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| Report number: LBNL-948E | Year: 2008 |
| Title: Energy Implications of Economizer Use in California Data Centers | Published in: |
| Authors: Shehabi, A., Ganguly, S., Travel, K., Price, H., Horvath, A., Nazaroff, W.W., Gadgil, A.J. | Type: Report |
| Report number: LBNL-306E | Year: 2008 |
| Title: Towards a Sustainable Energy Balance: Progressive Efficiency and the Return of Energy Conservation | Published in: Submitted to Energy Efficiency. |
| Authors: Harris, J., Diamond, R.C., Iyer, M., Payne, C., Blumstein, C., Siderius, H.P. | Type: Journal Article |
| Report number: LBNL-322E | Year: 2008 |
| Title: Greening the U.S. House of Representatives | Published in: |
| Authors: Diamond, R.C., Payne, C. | Type: Report |
| Report number: LBNL-59293 | Year: 2006 |
| Title: Indoor Air Quality Impacts of a Peak Load Shedding Strategy for a Large Retail Building | Published in: |
| Authors: Hotchi, T., Hodgson, A., Fisk, W. J. | Type: Report |
| Report number: LBNL-59853 | Year: 2006 |
| Title: Evaluating the energy performance of the first generation of LEED-certified commercial buildings | Published in: ACEEE 2006 Summer Study, Volume 3, Pages 245-257. |
| Authors: Diamond, R., Opitz, M., Hicks, T., Vonneida, B., Herrera, S. | Type: Conference Proceedings |
| Abstract: Over three hundred buildings have been certified under the Leadership in Energy and Environmental Design (LEED) rating system for sustainable commercial buildings as of January 2006. This paper explores the modeled and actual energy performance of a sample of 21 of these buildings that certified under LEED between December 2001 and August 2005, including how extensively the design teams pursued LEED energy-efficiency credits, the modeled design and baseline energy performance, and the actual energy use during the first few years of operation. We collected utility billing data from 2003-2005 and compared the billed energy consumption with the modeled energy use. We also calculated Energy Star ratings for the buildings and compared them to peer groups where possible. The mean savings modeled for the sample was 27% compared to their modeled baseline values. For the group of 18 buildings for which we have both modeled and billed energy use, the mean value for actual consumption was 1% lower than modeled energy use, with a wide variation around the mean. The mean Energy Star score was 71 out of a total of 100 points, higher than the average score of 50 but slightly below the Energy Star award threshold of 75 points. The paper discusses the limitations inherent to this type of analysis, such as the small sample size of disparate buildings, the uncertainties in actual floor area, and the discrepancies between metered sections of the buildings. Despite these limitations, the value of the work is that it presents an early view of the actual energy performance for a set of 21 LEED-certified buildings. | |
| Report number: LBNL-58252 | Year: 2005 |
| Title: Rationale For Measuring Duct Leakage Flows in Large Commercial Buildings | Published in: 26th AIVC International Conference, Pages pp. 83-88. |
| Authors: Wray, C.P., Diamond, R., Sherman, M. | Type: Conference Proceedings |
| Abstract: Industry-wide methods of assessing duct leakage are based on duct pressurization tests, and focus on "high pressure" ducts. Even though "low pressure" ducts can be a large fraction of the system and tend to be leaky, few guidelines or construction specifications require testing these ducts. We report here on the measured leakage flows from ten large commercial duct systems at operating conditions: three had low leakage (less than 5% of duct inlet flow), and seven had substantial leakage (9 to 26%). By comparing these flows with leakage flows estimated using the industry method, we show that the latter method by itself is not a reliable indicator of whole-system leakage flow, and that leakage flows need to be measured. | |
| Report number: LBNL-58580 | Year: 2005 |
| Title: Is Efficiency Enough? Towards a New Framework for Carbon Savings in the California Residential Sector | Published in: |
| Authors: Moezzi, M., Diamond, R. | Type: Report |
| Abstract: Mainstream implementations of energy efficiency in the United States are not adequately aligned with the environmental benefits claimed for efficiency, as they do not consider absolute levels of energy use, pollutant emissions, or consumption, and at times even encourage consumption. By understanding the lack of synchronization between environmental objectives and efficiency as it has been implemented, a more effective basis for policy can be reached. Our research seeks to motivate and initiate exploration of alternative modes of defining efficiency or otherwise moderating energy use toward addressing environmental objectives, as applicable to residential electricity use in California. We offer three main recommendations: 1) Consider integrating absolute consumption into technical definitions of efficiency, 2) Attend to the social messages of energy efficiency communications and in general better integrate the environmental consequences of energy use, and 3) Develop a more critical perspective on benefits and limitations of energy efficiency for delivering environmental benefits. In keeping with the exploratory nature of this project, we identify ten questions for further investigation. | |
| Report number: LBNL-57277 | Year: 2005 |
| Title: Improving Indoor Environmental Quality and Energy Performance of Modular Classroom HVAC Systems | Published in: Proceedings of Sustainable Buildings 2005 Conference, Pages 1432-1437. |
| Authors: Apte, M G., Spears, M., Lai, C.M., Shendel, D.G. | Type: Conference Proceedings |
| Abstract: The factory-built relocatable classroom (RC) is a dominant force in the school facility construction industry in the United States (U.S.) and elsewhere. It is estimated that there are approximately 650,000 RCs currently occupied in the U.S., housing about 16 million students. RCs receive public attention due to complaints about poor indoor environmental quality (IEQ). Both measured data and anecdotal evidence in California have suggested excessive acoustical noise from heating, ventilation, and air conditioning (HVAC) equipment as a central factor leading to degraded IEQ. In the U.S., RCs are typically equipped with unitary exterior wall-mount HVAC systems, and interior acoustical noise due to structural and airborne transmission can reach levels of about 58dB(A) with compressor cycling, under unoccupied conditions. Due to these noise levels teachers often simply choose to turn off the HVAC, leading to inadequate ventilation, as well as poor thermal conditioning, and thus to poor indoor air quality. Elevated levels of carbon dioxide and volatile organic compounds including formaldehyde are common. We discuss the acoustic component of our efforts to develop and test energy efficient HVAC systems that address the ventilation, controls, and acoustic requirements necessary to ensure high quality indoor environments in RCs. | |
| Report number: LBNL-57172 | Year: 2005 |
| Title: Improving Relocatable Classroom HVAC For Improved IEQ And Energy Efficiency | Published in: Indoor Air 2005 Conference - The 10th International Conference on Indoor Air Quality and Climate, Volume 1(7), Pages 1121-1125. |
| Authors: Apte, M G., Faulkner, D, Fisk, W.J., Hodgson, A.T., Hotchi, T., Lai, C.M., Spears, M., Sullivan, D.P., Wang, D. | Type: Conference Proceedings |
| Abstract: Relocatable classrooms (RCs) in California (CA) alone house about 2 million students in more than 80,000 structures. These buildings are typically under-ventilated, often due to low HVAC utilization because of excessive HVAC acoustic noise, and because when automatically operated they only ventilate during thermal conditioning. It can be predicted that such conditions affect the quality education and student health. These systems are also energy inefficient and peak-load demanding. With a manufacturer of wall-mounted HVAC systems, we are developing a new system addressing these problems. Design goals include a =30% increase the seasonal energy efficiency ratio (SEER) over the current SEER 10 system, noise reduction =45 dB(A), continuous ventilation meeting CA State code requirements (e.g. ASHRAE 62.1 ventilation standard of 7 l s-1 per occupant and a pre-occupancy air purge). The prototype was operated in an RC test-bed to characterize its performance from the standpoint of ventilation, and thermal control, acoustical noise, and energy consumption. Ten of the new HVAC systems are also being monitored for one year in matched pairs with the current standard HVAC systems after being installed in identical occupied RCs in four schools in Northern and Southern CA. Continuous measurements include indoor and outdoor carbon dioxide, temperature, relative humidity, and HVAC power consumption. Additionally, acoustical noise levels; thermal comfort; and concentrations of volatile organic compounds, formaldehyde and acetaldehyde, and ozone will be measured on a regular schedule throughout the study year. Daily classroom occupancy rates will be collected from the class records. The potential IEQ and energy savings benefits of the system will be presented from preliminary data collected in the field. | |
| Report number: LBNL-54230 | Year: 2004 |
| Title: Energy savings estimates and cost benefit calculations for high performance relocatable classrooms | Published in: |
| Authors: Rainer, L., Hoeschele, M., Apte, M.G., Shendell, D.G., Fisk, W.J. | Type: Report |
| Abstract: This report addresses the results of detailed monitoring completed under Program Element 6 of Lawrence Berkeley National Laboratory's High Performance Commercial Building Systems (HPCBS) PIER program. The purpose of the Energy Simulations and Projected State-Wide Energy Savings project is to develop reasonable energy performance and cost models for high performance relocatable classrooms (RCs) across California climates. A key objective of the energy monitoring was to validate DOE2 simulations for comparison to initial DOE2 performance projections. The validated DOE2 model was then used to develop statewide savings projections by modeling base case and high performance RC operation in the 16 California climate zones. The HPCBS energy efficient RC design is based upon earlier work by Davis Energy Group with Pacific Gas and Electric Company (PG&E), which culminated in the PG&E Premium Efficient Relocatable Classroom (PERC) program (DEG 1997). The envelope energy efficiency measures selected for the HPCBS project are similar to the PERC Package 1 except the HPCBS package substitutes a white ("Cool Roof") coating for the radiant barrier in the attic space. In addition to the standard wall-mount heat pump system (HPAC), the HPCBS RCs utilize an advanced hybrid system combining an Indirect/Direct Evaporative Cooler (IDEC), which provides two-stage evaporative cooling, and an instantaneous gas-fired heater and hydronic coil for heating. Simulations described in this report add upon those conducted in program year one, with the benefit of data collected during the energy and indoor air and environmental quality (IEQ) field monitoring. Data from the field studies have been used to improve model inputs. The revised DOE2 analyses presented here provide an improved assessment of statewide energy performance for both base case and high performance RCs. Since the initiation of this project a new revision of the California Title 24 Building Standards has begun (scheduled for release in 2005). As part of this process, RCs were examined and new code enforcement procedures were developed which will result in new RCs having envelope energy features very close to the HPCBS design. Table 1 summarizes key energy features of the HPCBS RC package. Additional background information on the construction details and assumed operating characteristics of RCs, as well as full-year DOE2 performance projections, can be found in the 2001 project report entitled Relocatable Classroom DOE2 Analysis Report, (Apte et al 2001, Shendell et al 2002) | |
| Report number: LBNL-54191 | Year: 2004 |
| Title: A prototype data archive for the PIER "thermal distribution systems in commercial buildings" project | Published in: |
| Authors: Diamond, R.C., Wray, C.P., Smith, B.V., Dickerhoff, D.J., Matson, N.E., Cox, S.A. | Type: Report |
| Abstract: A prototype archive for a selection of building energy data on thermal distribution systems in commercial buildings was developed and pilot tested. While the pilot demonstrated the successful development of the data archive prototype, several questions remain about the usefulness of such an archive. Specifically, questions on the audience, frequency of use, maintenance, and updating of the archive would need to be addressed before this prototype is taken to the next level. | |
| Report number: LBNL-56173 | Year: 2004 |
| Title: An R&D guide and multiyear plan for improving energy use in existing commercial buildings | Published in: |
| Authors: Diamond, R. | Type: Report |
| Report number: LBNL-53785 | Year: 2003 |
| Title: Worker productivity and ventilation rate in a call center: Analyses of time-series data for a group of registered nurses | Published in: |
| Authors: Fisk, W.J., Price, P.N., Faulkner, D., Sullivan, D.P., DiBartolomeo, D.L., Federspiel, C., Liu, G., Lahiff, M. | Type: Report |
| Abstract: We investigated the relationship of ventilation rates with the performance of advice nurses working in a call center. Ventilation rates were manipulated; temperatures, humidities, and CO2 concentrations were monitored; and worker performance data, with 30-minute resolution, were collected. Multivariate linear regression was used to investigate the association of worker performance with indoor minus outdoor CO2 concentration (which increases with decreasing ventilation rate per worker) and with building ventilation rate. Results suggest that the effect of ventilation rate on worker performance in this call center was very small (probably less than 1%) or nil, over most of the range of ventilation rate (roughly 12 L s-1 to 48 L s-1 per person). However, there is some evidence of worker performance improvements of 2% or more when the indoor CO2 concentration exceeded the outdoor concentration by less than 75 ppm.[1067] | |
| Report number: LBNL-50969 | Year: 2003 |
| Title: A lifestyle-based scenario for U.S. buildings: Implications for energy us | Published in: Energy Policy, Volume 31, Pages 1205-1211. |
| Authors: Diamond, Rick. 2003. | Type: Journal Article |
| Abstract: Can lifestyle-based scenarios provide insight into the nature of energy use in our future buildings? Participants in a design charrette brainstormed ideas about the future of US homes and workplaces. The teams started from several descriptions of daily lifestyles, and developed specific building characteristics as the place settings for these narratives. In addition to characterizing the physical environment, the teams also identified the forces that would be influential in making these changes. Further reflection was made on the possible unintended consequences of these changes. The energy implications of these changes were characterized with respect to magnitude and direction. While acknowledging the speculative nature of the exercise, the rationale was to broaden the discussion on future energy use by looking at future scenarios in the context of everyday life. | |
| Report number: LBNL-52690 | Year: 2003 |
| Title: Simultaneous Energy Savings and IEQ Improvements in Relocatable Classrooms | Published in: |
| Authors: Apte, M.G., Hodgson, A.T., Shendell, D.G., Dibartolomeo, D., Hotchi, T., Lee, S.M., Liff, S.M., Rainer, L.I., Sullivan, D.P., Fisk, W.J.. | Type: Report |
| Abstract: Relocatable classrooms (RCs) are commonly used by school districts with changing demographics and enrollment sizes. We designed and constructed four energy-efficient RCs for this study to demonstrate technologies with the potential to simultaneously improve energy efficiency and indoor environmental quality (IEQ). Two were installed at each of two school districts, and energy use and IEQ parameters were monitored during occupancy. Two RCs (one per school) were finished with materials selected for reduced emissions of toxic and odorous volatile organic compounds (VOCs). Each had two HVAC systems, operated on alternate weeks, consisting of a standard heat-pump system and an indirect-direct evaporative cooling (IDEC) system with gas-fired hydronic heating. The IDEC system provides continuous outside air ventilation at "15 CFM (7.5 L s-1) person-1, efficient particle filtration while using significantly less energy for cooling. School year long measurements included: carbon dioxide (CO2), particles, VOCs, temperature, humidity, thermal comfort, noise, meteorology, and energy use. IEQ monitoring results indicate that important ventilation-relevant indoor CO2 and health-relevant VOC concentration reductions were achieved while average cooling and heating energy costs were simultaneously reduced by 50% and 30%, respectively. | |
| Report number: LBNL-54870 | Year: 2003 |
| Title: Simultaneous Improvements in Relocatable Classrooms | Published in: ASHRAE IAQ Applications, Pages 7-10. |
| Authors: Apte, M G., Hodgson, A., Shendel, D.G., Dibartolomeo, D., Hotchi, T., Lee, S-M, Liff, S., Rainer, L., Sullivan, D, Fisk, W.J. | Type: Journal Article |
| Report number: LBNL-50704 | Year: 2002 |
| Title: Becoming allies: Combining social science and technological perspectives to improve energy research and policy making | Published in: Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 4, Pages 89-104. |
| Authors: Diamond, R.C., M. Moezzi | Type: Conference Proceedings |
| Abstract: Within the energy research community, social sciences tends to be viewed fairly narrowly, often as simply a marketing tool to change the behavior of consumers and decision makers, and to "attack market barriers." As we see it, social sciences, which draws on sociology, psychology, political science, business administration, and other academic disciplines, is capable of far more. A social science perspective can re- align questions in ways that can lead to the development of technologies and technology policy that are much stronger and potentially more successful than they would be otherwise. In most energy policies governing commercial buildings, the prevailing R&D directives are firmly rooted in a technology framework, one that is generally more quantitative and evaluative than that fostered by the social sciences. To illustrate how social science thinking would approach the goal of achieving high energy performance in the commercial building sector, we focus on the U.S. Department of Energy's Roadmap for commercial buildings (DOE 2000) as a starting point. By "deconstructing" the four strategies provided by the Roadmap, we set the stage for proposing a closer partnership between advocates of technology-based and social science-based approaches. | |
| Report number: LBNL-45867 | Year: 2001 |
| Title: Fault Detection in HVAC Systems Using Model-Based Feedforward Control | Published in: Energy & Buildings, Volume 33, Pages 403-415. |
| Authors: Salsbury, T.I., Diamond, R.C. | Type: Journal Article |
| Report number: LBNL-47942 | Year: 2001 |
| Title: Demand-Responsive and Efficient Building Systems as a Resource for Electricity Reliability | Published in: |
| Authors: Piette, M.A., J.H. Eto, I.S. Walker, S. Selkowitz, C.P. Wray, B. Nordman, A. Meier, P. Haves, R. Diamond, J. Harris, M. Moezzi, C. Payne, J. Koomey | Type: Report |
| Report number: LBNL-45863 | Year: 2000 |
| Title: Implementation and testing of a fault detection software tool for improving control system performance in a large commercial building | Published in: Proceedings of the ACEEE 2000 Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 7, Pages 147-158. |
| Authors: Salsbury, T.I., Diamond, R.C. | Type: Conference Proceedings |
| Report number: LBNL-43640 | Year: 2000 |
| Title: An Overview of the U.S. Building Sector | Published in: Chapter 6 in Indoor Air Quality Handbook. |
| Authors: Diamond, R.C., Spengler, J.D., Samet, J.M., McCarthy, J.F. | Type: Book Section |
| Report number: LBNL-43256 | Year: 1999 |
| Title: Phillip Burton Federal Building: EMCS Retrofit Analysis | Published in: |
| Authors: Diamond, R.C., Salsbury, T., Bell, G., Huang, Y.J., Sezgen, O., Mazzuchi, R., Roberger, J. | Type: Report |
| Report number: LBNL-42556 | Year: 1998 |
| Title: Model Procurement Documents | Published in: |
| Authors: Matson, N.E., Sartor, D.A., Diamond, R.C. | Type: Report |
| Report number: PUB-798 | Year: 1997 |
| Title: Tenant Guidelines for Energy-Efficient Renovation of Buildings at the Presidio of San Francisco | Published in: |
| Authors: Warner, J., Sartor, D., Diamond, R. | Type: Report |
| Report number: | Year: 1997 |
| Title: Multifamily ventilation | Published in: Home Energy, Volume 14. |
| Authors: Diamond,R.C. | Type: Journal Article |
| Report number: | Year: 1996 |
| Title: Designing an Environmental Showcase: The San Francisco Presidio | Published in: Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 5, Pages 209-218. |
| Authors: Sartor, D. A., Diamond, R. C., Walker, A., Giller, M., Brown, K., Crawley, A. S. | Type: Conference Proceedings |
| Report number: LBL-31636 | Year: 1996 |
| Title: Improving the Energy Efficiency of Air Distribution Systems in New California Homes | Published in: Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 2, Pages 85-95. |
| Authors: Hammon, R.W., Modera M.P. | Type: Conference Proceedings |
| Report number: | Year: 1996 |
| Title: User Satisfaction with Innovative Cooling Retrofits in Sacramento Public Housing | Published in: Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 8, Pages 21. |
| Authors: Diamond, R.C., Remus, J., Vincent, B. | Type: Conference Proceedings |
| Report number: | Year: 1996 |
| Title: Improving Energy Efficiency in Apartment Buildings | Published in: |
| Authors: DeCicco, J., Diamond, R. C., Nolden, S., Wilson, T. | Type: Book Section |
| Report number: | Year: 1996 |
| Title: Does the Feebate Approach to A/E Compensation Lead to and Energy-Efficient Building? | Published in: Proceedings of the 4th National Energy-Efficient New Construction Conference, Vancouver, BC. |
| Authors: Busch, J., Diamond, R. C. | Type: Conference Proceedings |
| Report number: | Year: 1995 |
| Title: Architecture in North America since 1960 | Published in: |
| Authors: Tzonis, A., Lefaivre, L., Diamond, R. | Type: Book Section |
| Report number: LBL-36506 | Year: 1995 |
| Title: Findings from a Low-Energy, New Commercial-Buildings Research and Demonstration Project | Published in: Energy, Volume 20, Pages 471-482. |
| Authors: Piette, M. A., Nordman, B., Buen, O. D., Diamond, R. C. | Type: Journal Article |
| Report number: | Year: 1995 |
| Title: Energy and Ventilation Research in Highrise Apartments: The Chelsea Public Housing Study | Published in: Proceedings of the 15th AIVC Annual Conference, Palm Springs, CA. |
| Authors: Diamond, R.C., Feustel, H.E., Dickerhoff, D.J. | Type: Conference Proceedings |
| Report number: | Year: 1995 |
| Title: An Overview of the Multifamily Sector | Published in: Home Energy, Volume 12, Pages 22-25. |
| Authors: Diamond, R.C. | Type: Journal Article |
| Report number: LBNL-61870 | Year: 2008 |
| Title: Risk factors in heating, ventilating, and air-conditioning systems for occupant symptoms in U.S. office buildings: the U.S. EPA BASE study | Published in: Indoor Air (In Press). |
| Authors: Mendell, M.J., Lei-Gomez, Q., Mirrer, A., Seppanen, O., Brunner, G. | Type: Journal Article |
| Abstract: Background: Nonspecific building-related symptoms among occupants of modern office buildings worldwide are common and may be associated with important reductions in work performance, but their etiology remains uncertain. Characteristics of heating, ventilating, and air-conditioning (HVAC) systems in office buildings that increase risk of indoor contaminants or reduce effectiveness of ventilation may cause adverse exposures and subsequent increase in these symptoms among occupants. Methods: We analyzed data collected by the U.S. Environmental Protection Agency (EPA) from a representative sample of 100 large U.S. office buildings – the Building Assessment and Survey Evaluation (BASE) study – using multivariate-adjusted logistic regression models with generalized estimating equations. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between seven building-related symptom outcomes and selected HVAC system characteristics (excluding ventilation rate, analyzed elsewhere) in the 97 airconditioned study buildings. Results: Among factors of HVAC design or configuration: Outdoor air intakes less than 60 m above the ground were associated with substantially increased odds of most symptoms assessed (ORs up to 2.7). Among factors of HVAC condition, maintenance, or operation: the presence of humidification systems in good condition was associated with reduction in skin symptoms (OR=0.5), whereas the presence of humidification systems in poor condition was associated with increases in upper respiratory symptoms, eye symptoms, fatigue/difficulty concentrating, and skin symptoms (ORs=1.5 to 1.7). Lack of regularly scheduled inspections for HVAC components was associated with increased eye and upper respiratory symptoms (ORs=2.2, 1.6). Less frequent cleaning of cooling coils or condensate drain pans was associated with increased headache and eye symptoms (ORs=1.5, 1.5). Ventilation for 10-12 hours per day (relative to more) was associated with a general slight increase in symptoms, especially fatigue/difficulty concentrating (OR=1.3). Several specific associations opposite of predicted were found, such as with cleanliness of air handler components and operational condition of air handling components. Discussion: Most of the many potential risk factors assessed here had not been investigated previously, and associations found with single symptom groups may have been by chance, including some that were the reverse of expected. Risk factors newly identified in these analyses that deserve attention include outdoor air intakes less than 60 m above the ground (which were correlated with higher levels of some outdoor vehicle-emitted pollutants), poorly maintained humidification systems, and lack of scheduled inspection for HVAC systems. Infrequent cleaning of cooling coils and drain pans were associated with increases in several symptoms in these as well as prior analyses of BASE data. Replication of these findings is needed, using more objective measurements of both exposure and health response. Confirmation of the specific HVAC factors responsible for increased symptoms in buildings, and development of prevention strategies could have major public health and economic benefits worldwide. | |
| Report number: LBNL-62419 | Year: 2008 |
| Title: Outdoor Ozone and Building Related Symptoms in the BASE Study | Published in: Indoor Air, Volume 18, Pages 156-170. |
| Authors: Apte, M.G., Buchanan, I.S., Mendell, M. J. | Type: Journal Article |
| Abstract: Reactions between ozone and indoor contaminants can influence human health and indoor air quality. The U.S. EPA Building Assessment Survey and Evaluation (BASE) study data were analyzed for associations between outdoor ozone concentrations and building related symptom (BRS) prevalence. Multiple logistic regression (MLR) models, adjusted for personal, workplace and environmental variables, revealed positive relationships (p<0.05) between ozone concentrations and upper respiratory (UR), dry eyes, neurological and headache BRS (odds ratios ranged from 1.03-1.04 per 10 μg m 3 increase in outdoor ozone concentrations). Other BRS had marginally significant relationships with ozone (p<0.10). A linear dose-response in UR symptoms was observed with increasing outdoor ozone (p=0.03); most other symptoms showed similar but not statistically significant trends. Outdoor ozone correlated with indoor concentrations of several aldehydes, a pattern suggesting that indoor ozone chemistry was occurring. Coupled with the MLR ozone-BRS analysis, this correlation supports the hypothesis that ozone-initiated indoor reactions play an important role in the indoor air quality and building occupant health. Replication with increased statistical power and with longitudinal data is needed. If the observed associations are confirmed as causal, ventilation system ozone removal technologies could improve building occupant health when higher ambient ozone levels are present. | |
| Report number: LBNL-63005 | Year: 2007 |
| Title: Indoor Environment, Productivity in Offices | Published in: ASHRAE IAQ Applications, Volume 8, Pages 1-15. |
| Authors: Seppanen, O., Fisk, W.J., Wargocki, P. | Type: Journal Article |
| Report number: LBNL-63007 | Year: 2007 |
| Title: Public health and economic impact of dampness and mold | Published in: Indoor Air, Volume 17, Pages 226-235. |
| Authors: Mudarri, D., Fisk, W.J. | Type: Journal Article |
| Abstract: The public health risk and economic impact of dampness and mold exposures was assessed using current asthma as a health endpoint. Individual risk of current asthma from exposure to dampness and mold in homes from Fisk et al. (2007), and asthma risks calculated from additional studies that reported the prevalence of dampness and mold in homes were used to estimate the proportion of U.S. current asthma cases that are attributable to dampness and mold exposure at 21% (95% confidence internal 12-29%). An examination of the literature covering dampness and mold in schools, offices, and institutional buildings, which is summarized in the appendix, suggests that risks from exposure in these buildings are similar to risks from exposures in homes. Of the 21.8 million people reported to have asthma in the U.S., approximately 4.6 (2.7-6.3) million cases are estimated to be attributable to dampness and mold exposure in the home. Estimates of the national cost of asthma from two prior studies were updated to 2004 and used to estimate the economic impact of dampness and mold exposures. By applying the attributable fraction to the updated national annual cost of asthma, the national annual cost of asthma that is attributable to dampness and mold exposure in the home is estimated to be $3.5 billion ($2.1 - 4.8 billion). Analysis indicates that exposure to dampness and mold in buildings poses significant public health and economic risks in the U.S. These findings are compatible with public policies and programs that help control moisture and mold in buildings. | |
| Report number: LBNL-63370 | Year: 2007 |
| Title: Contaminants in Buildings and Occupied Spaces as Risk Factors for Occupant Symptoms in U.S. Office Buildings: Findings from the U.S. EPA BASE Study | Published in: |
| Authors: Mendell, M. J., Mirer, A., Lei-Gomez, Q. | Type: Report |
| Abstract: Background: Nonspecific building-related symptoms among occupants of modern office buildings worldwide are common and may be associated with important reductions in work performance, but their etiology remains uncertain. Most reported research into environmental risk factors for these symptoms has focused on ventilation system-related factors, dampness, and particle removal through filtration and cleaning, with relatively few studies of other potential sources of indoor contaminants. Methods: We analyzed data collected by the U.S. Environmental Protection Agency (EPA) from a representative sample of 100 large U.S. office buildings – the Building Assessment and Survey Evaluation (BASE) study – using multivariate-adjusted logistic regression models with generalized estimating equations. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between seven building-related symptom outcomes and a diverse set of potential indoor and outdoor sources for indoor pollutants. Results: Although most of the investigated risk factors showed no apparent association with building-related symptoms, some interesting associations resulted. Increased prevalence of symptoms was associated with carpets older than one year (lower respiratory symptoms), non-carpeted floors (upper and lower respiratory symptoms), older furniture (eye and skin symptoms), infrequent vacuuming (upper respiratory, eye, and skin symptoms and headache), and masonry exterior walls (cough, eye symptoms, and fatigue/concentration difficulty). Discussion: For the many potential risk factors assessed, almost none had been investigated previously, and many associations found here may have been by chance. Additional confirmatory research focused on risk factors initially identified here is needed, using more objective measures of health outcomes and risk factors or exposures | |
| Report number: LBNL-61280 | Year: 2007 |
| Title: Indoor residential chemical emissions as risk factors for respiratory and allergic effects in children: A Review | Published in: Indoor Air, Volume 17, Pages 259-277. |
| Authors: Mendell, M. | Type: Journal Article |
| Report number: LBNL-58516 | Year: 2006 |
| Title: Ventilation and Work Performance in office work | Published in: Indoor Air, Volume 16, Pages 28-36. |
| Authors: Seppanen, O., Fisk, W.J., Lei-Gomez, Q. | Type: Journal Article |
| Abstract: Outdoor air ventilation rates vary considerably between and within buildings, and may be too low in some spaces. The purpose of this study was to evaluate the potential work performance benefits of increased ventilation. We analysed the literature relating work performance with ventilation rate and employed statistical analyses with weighting factors to combine the results of different studies. The studies included in the review assessed performance of various tasks in laboratory experiments and measured performance at work in real buildings. Almost all studies found increases in performance with higher ventilation rates. The studies indicated typically a 1-3 % improvement in average performance per 10 L/s-person increase in outdoor air ventilation rate. The performance increase per unit increase in ventilation was bigger with ventilation rates below 20 L/s-person and almost negligible with ventilation rates over 45 L/s-person. The performance increase was statistically significant with increased ventilation rates up to 15 L/s-person with 95% CI and up to 17 L/s-person with 90% CI. | |
| Report number: LBNL-60946 | Year: 2006 |
| Title: Effect of temperature on task performance in office environment | Published in: 5th International Conference on Cold Climate Heating, Ventilating and Air Conditioning, Pages 53-16. |
| Authors: Seppanen, O., Fisk, W. J., Lei, Q. H. | Type: Conference Proceedings |
| Abstract: Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with a degree of accuracy dependent on the building and its HVAC system. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance at work. In this study, we focused on the effects of temperature on performance at office work. . We included those studies that had used objective indicators of performance that are likely to be relevant in office type work, such as text processing, simple calculations (addition, multiplication), length of telephone customer service time, and total handling time per customer for call-center workers. We excluded data from studies of industrial work performance. We calculated from all studies the percentage of performance change per degree increase in temperature, and statistically analyzed measured work performance with temperature. The results show that performance increases with temperature up to 21-22 oC, and decreases with temperature above 23-24 oC. The highest productivity is at temperature of around 22 oC. For example, at the temperature of 30 oC the performance is only 91.1% of the maximum i.e. the reduction in performance is 8.9% | |
| Report number: LBNL-60952 | Year: 2006 |
| Title: Room temperature and productivity in office work | Published in: Healthy Buildings 2006 Conference, Volume 1, Pages 243-247. |
| Authors: Seppanen, O., Fisk, W.J., Lei, Q. H. | Type: Conference Proceedings |
| Abstract: Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with a degree of accuracy dependent on the building and its HVAC system. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance at work. In this study, we focused on the effects of temperature on performance at office work. . We included those studies that had used objective indicators of performance that are likely to be relevant in office type work, such as text processing, simple calculations (addition, multiplication), length of telephone customer service time, and total handling time per customer for call-center workers. We excluded data from studies of industrial work performance. We calculated from all studies the percentage of performance change per degree increase in temperature, and statistically analyzed measured work performance with temperature. The results show that performance increases with temperature up to 21-22 °C, and decreases with temperature above 23-24 °C. The highest productivity is at temperature of around 22 °C. For example, at the temperature of 30 °C the performance is only 91.1% of the maximum i.e. the reduction in performance is 8.9% | |
| Report number: LBNL-60951 | Year: 2006 |
| Title: A procedure to estimate the cost-effectiveness of the indoor environment improvements in office work | Published in: Creating the Productive Workplace, Pages 407-433. |
| Authors: Seppanen, O., Fisk, W.J., Derek Clements Croome | Type: Book Section |
| Report number: LBNL-59876 | Year: 2006 |
| Title: Some quantitative relations between Indoor environmental quality and work performance or health | Published in: International Journal of HVAC&R Research, Volume 12, Pages 957-973. |
| Authors: Seppanen, O., Fisk, W.J. | Type: Journal Article |
| Abstract: Poor indoor environmental quality (IEQ) has been related to increases in sick building syndrome symptoms, respiratory illnesses, sick leave, and losses in productivity. Calculations indicate that the cost of poor IEQ can be higher than energy costs space conditioning and ventilation, and that many measures taken to improve indoor IEQ will be highly cost-effective when accounting for the monetary savings resulting from an improved health or productivity. To enable building professionals to make selections of building designs and operating practices that account for effects on health and productivity, we need models for quantifying the health and productivity benefits of better indoor environments. Therefore, we have reviewed the literature on the effects of indoor environment on health and performance and used existing data, when possible, to develop some initial models. Based on the best-available evidence we present quantitative relationships between ventilation rate and short term sick leave, ventilation rate and work performance, perceived air quality and performance, temperature and performance, and temperature and sick building syndrome symptoms. We show also that a relationship exists between SBS symptoms (sick building syndrome symptoms) and work performance. | |
| Report number: LBNL-59659 | Year: 2006 |
| Title: Indoor Environmental Risk Factors for Occupant Symptoms in 100 U.S. Office Buildings: Summary of Three Analyses from the EPA BASE Study | Published in: Healthy Buildings 2006 Conference, Volume 111, Pages 371-376. |
| Authors: Mendell, M., Lei-Gomez, Q., Cozen, M., Brightman, H.S., Apte, M G., Erdmann, C.A., Brunner, G., Girman, J.R. | Type: Conference Proceedings |
| Abstract: This paper summarizes three analyses of data on building-related environmental factors and occupant symptoms collected from 100 representative large U.S. office buildings. Using multivariate logistic regression models, we found increased occupant symptoms associated with a number of building-related factors, including lower ventilation rates even at the current guideline levels, lack of scheduled cleaning for air-conditioning drain pans and cooling coils, poor condition of cooling coils, poorly maintained humidification systems, and lower outdoor air intake height. Some expected relationships were not found, and several findings were opposite of expected. Although requiring replication, these findings suggest preventive actions to reduce occupant symptoms in office buildings. | |
| Report number: LBNL-59329 | Year: 2006 |
| Title: Causes and prevention of symptom complaints in office buildings: Distilling the experience of indoor environmental quality investigators | Published in: Facilities 2006, Volume 24, Pages 436-444. |
| Authors: Mendell, M., Brennan, T, Hathon, L., Odom, J.D., Offerman, F.J., Turk, B.H., Wallingford, K.M., Diamond, R., Fisk, B. | Type: Journal Article |
| Abstract: ABSTRACT Purpose The goal of this project was to develop, based on the experience of those who investigate health complaints in buildings, practical strategies for preventing building-related symptoms in office buildings, suitable for use by those who own, lease, or manage office space. Methodology/approach Ideas from six experienced building investigators on primary causes and key prevention strategies were gathered and prioritized through consensus and voting in a structured, multi-day workshop. Findings The top ranked problems identified were, in priority order: excessive building moisture, inadequate outdoor air, dust on indoor surfaces, indoor gases and odors, inadequate thermal control, and inadequate attention by management to indoor environments. The highest priority strategies recommended for preventing building-related symptoms were: managing moisture at building exteriors, operating ventilation systems per design intent, providing at least minimum ventilation rates, and maintaining indoor temperatures at 72°F ±2°. Findings in the scientific literature were generally consistent with these recommendations. Research limitations/implications Findings reported here result from a subjective synthesis of empirical knowledge, not from scientific research, and have not yet been scientifically confirmed. Still, IEQ investigators showed considerable agreement on the most important causes of symptom complaints in office buildings and the key methods for preventing these problems. Practical implications These recommendations, generally consistent with available research findings, provide useful practical guidelines for those who own, manage or maintain office buildings. Originality/value The empirical knowledge of practitioners, concentrated and synthesized here, offers more guidance for choosing health-protective strategies in office buildings than current science. | |
| Report number: LBNL-59663 | Year: 2006 |
| Title: Air Filter Materials and Building Related Symptoms in the BASE Study | Published in: Healthy Buildings Conference 2006, Volume 4, Pages 455-460. |
| Authors: Buchanan, I.S., Apte, M.G. | Type: Conference Proceedings |
| Abstract: Mechanical ventilation of buildings is a risk factor for building related symptoms (BRS). This analysis examines air filters within mechanical ventilation systems to determine their effect on BRS. We hypothesize that certain ventilation filter materials will contribute more than others to the burden of building related headaches, mucous membrane (MM) and lower respiratory (LR) BRS within a building. This hypothesis was tested using the USEPA Building Assessment, Survey and Evaluation (BASE) study. Logistic regression models constructed to control for personal, workplace, and environmental factors reveled statistically significant (p<0.05) associations between the increased prevalence of building related headaches, certain MM and LR BRS and polyester or synthetic containing air filters in a ventilation system, relative to fiberglass or cotton air filters. | |
| Report number: LBNL-55447 | Year: 2005 |
| Title: A model to estimate the cost effectiveness of indoor environment improvements in office work | Published in: ASHRAE Transactions, Volume 111, Pages 663-679. |
| Authors: Seppanen, O., Fisk, W.J. | Type: Journal Article |
| Abstract: Deteriorated indoor climate is commonly related to increases in sick building syndrome symptoms, respiratory illnesses, sick leave, reduced comfort and losses in productivity. The cost of deteriorated indoor climate for the society is high. Some calculations show that the cost is higher than the heating energy costs of the same buildings. Also building-level calculations have shown that many measures taken to improve indoor air quality and climate are cost-effective when the potential monetary savings resulting from an improved indoor climate are included as benefits gained. As an initial step towards systemizing these building level calculations we have developed a conceptual model to estimate the cost-effectiveness of various measures. The model shows the links between the improvements in the indoor environment and the following potential financial benefits: reduced medical care cost, reduced sick leave, better performance of work, lower turn over of employees, and lower cost of building maintenance due to fewer complaints about indoor air quality and climate. The pathways to these potential benefits from changes in building technology and practices go via several human responses to the indoor environment such as infectious diseases, allergies and asthma, sick building syndrome symptoms, perceived air quality, and thermal environment. The model also includes the annual cost of investments, operation costs, and cost savings of improved indoor climate. The conceptual model illustrates how various factors are linked to each other. SBS symptoms are probably the most commonly assessed health responses in IEQ studies and have been linked to several characteristics of buildings and IEQ. While the available evidence indicates that SBS symptoms can affect these outcomes and sugpects that such a linkage exists, at present we can not quantify the relationships sufficiently for cost-benefit modeling. New research and analyses of existing data to quantify the financial importance of SBS symptoms would enable more widespread consideration of the effects of IEQ in cost benefit calculations. | |
| Report number: LBNL-55448 | Year: 2005 |
| Title: Control of temperature for health and productivity in offices | Published in: ASHRAE Transactions, Volume 111, Pages 680-686. |
| Authors: Seppanen, O., Fisk, W.J. | Type: Journal Article |
| Abstract: Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with different accuracy depending on the building and its HVAC system. The purpose of this study was to evaluate the potential benefits of improved temperature control, and apply the information for a cost-benefit analyses. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance in work. In this study we focused on the effects of temperature on performance in work. We collected and analyzed the literature relating the performance in work and temperature. The results of multiple studies are relatively consistent and show an average relationship of 2% decrement in work performance per degree oC when the temperature is above 25oC. Less data were available on the performance in low temperatures. However, studies show a strong effect on manual tasks with temperatures below thermal neutrality as soon as the temperature of hands decreased due to control of blood flow. When the estimated productivity decrement from elevated temperetures was applied to data from a study of night-time ventilative cooling, the estimated value of productivty improvements were 32 to 120 times greater than the cost of energy to run fans during the night. | |
| Report number: No LBNL number | Year: 2005 |
| Title: Some quantitative relations between indoor environment, performance and health | Published in: Proceedings of The 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume I(1), Pages 40-53. |
| Authors: Seppanen, O., Fisk, B. | Type: Conference Proceedings |
| Report number: LBNL-56381 | Year: 2005 |
| Title: Outdoor Air Ventilation and Work-Related Symptoms in U.S. Office Buildings - Results from the Base Study | Published in: |
| Authors: Mendell, M.J. , Lei, Q., Apte, M.G. , Fisk, W.J. | Type: Report |
| Abstract: Background: Recommendations for outdoor air ventilation rates in office buildings balance the need to dilute indoor pollutants for both health and comfort of the occupants against the costs of thermally conditioning the outdoor air. Although little scientific information has been available on the relationships between measured ventilation rates and health symptoms in office workers, a recently collected data set allows investigation of these relationships. Methods: We performed analyses using data on work-related symptoms and ventilation rates collected by the U.S. EPA from a representative sample of 100 large U.S. office buildings – the Building Assessment and Survey Evaluation (BASE) study. Using multivariate logistic regression models for building-related lower respiratory and mucous membrane irritation symptoms, we estimated relative risks, as odds ratios, for three methods of estimating ventilation rate/person, adjusted for occupancy density and other confounders. The three ventilation rate measurement methods were based on CO2 ratio in airstreams, peak CO2 concentrations indoors, and volumetric estimates of flow rates. Results: We found a general but irregular association of lower symptom prevalence with ventilation rates above the current recommended minimum for office space (about 20 cfm/person), but found no evidence for further increased benefits as ventilation rates continued to increase above 26, 32, or 37 cfm/person (depending on the measurement method). This relationship, however, did not hold for the volumetric method and lower respiratory symptoms. Also, for all measurement methods, even with ventilation per person held constant, medium to high occupancy density was associated with more symptoms than low occupancy density. Discussion: These findings suggest, although not with complete consistency, that raising ventilation rates above current recommendations would reduce symptoms in office workers. The inconsistent findings for different measurement methods of ventilation were surprising. Occupancy density may play an unrecognized role in ventilation requirements. Further clarification of these relationships is necessary, as is the validation of accurate methods for measuring ventilation rates. | |
| Report number: LBNL-57102 | Year: 2005 |
| Title: Estimated Ventilation Rates and Work-Related Symptoms in U.S. Office Buildings - The Base Study | Published in: 10th International Conference on Indoor Air Quality and Climate, Volume 5(6), Pages 3758-3762. |
| Authors: Mendell, M.J., Lei, Q., Apte, M G., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: Insufficient information has been available on measured ventilation rates and symptoms in office workers. Using U.S. EPA data from 100 large U.S. office buildings, we assessed relationships in multivariate models between ventilation/person and lower respiratory and mucous membrane symptoms. Three preliminary ventilation estimates were used, based on CO2 ratio in airstreams, peak indoor CO2 concentrations, and volumetric estimates of flow rates. Ventilation rates (VRs) from 6-17 cfm/person above the current 20 cfm/person guideline for offices were associated generally with reduced symptom prevalence, but further benefits were not evident from higher VRs. For all ventilation estimates, higher occupant density was independently associated with more symptoms. Findings suggest that VRs somewhat above current guidelines would reduce symptoms in office workers, and that occupant density may play an unrecognized role in ventilation requirements. Different findings for the various ventilation estimates were surprising. Clarification of these relationships, and validation of VR measurement methods are necessary. | |
| Report number: LBNL-51780 | Year: 2005 |
| Title: Do Indoor Pollutants and Thermal Conditions in Schools Influence Student Performance? A Critical Review of the Literature | Published in: Indoor Air 2005, Volume 15, Pages 27-52. |
| Authors: Mendell, M.J., Heath, G.A. | Type: Journal Article |
| Abstract: Limited research is available on potential adverse effects of school environments on academic performance, despite strong public concern. We examine the scientific evidence relevant to this relationship by reviewing available research relating schools and other indoor environments to human performance or attendance. As a primary focus, we critically review evidence for direct relationships between indoor environmental quality (IEQ) in buildings and performance or attendance. As a secondary focus, we summarize, without critique, evidence on potential connections indirectly linking IEQ to performance or attendance: relationships between IEQ and health, between health and performance or attendance, and between attendance and performance. The most persuasive direct evidence showed increases in indoor concentrations of nitrogen dioxide and outdoor concentrations of several specific pollutants to be related to reduced school attendance. The most persuasive indirect evidence showed indoor dampness and microbiologic pollutants to be related to asthma and respiratory infections, which have in turn been related to reduced performance and attendance. Furthermore, a substantial scientific literature links poor IEQ (e.g., low ventilation rate, excess moisture or formaldehyde) with respiratory and other health effects in children and adults. Overall, evidence suggests that poor IEQ in schools can influence the performance and attendance of students, primarily through health effects from indoor pollutants. Also, inadequate IEQ in schools seems sufficiently common to merit strong public concern. Evidence is available to justify (1) immediate actions to protect IEQ in schools and (2) focused research on exposures, prevention, and causation, to better guide policies and actions on IEQ in schools. | |
| Report number: LBNL-57101 | Year: 2005 |
| Title: Indicators Of Moisture And Ventilation System Contamination In U.S. Office Buildings as Risk Factors for Respiratory and Mucous Membrane Symptoms: Analyses of the EPA Base Data | Published in: 10th International Conference on Indoor Air Quality and Climate, Volume 5(6), Pages 3763-3767. |
| Authors: Mendell, M., Cozen, M., Lei, Q., Brightman, H.S., Edrmann, C.A., Girman, J.R., Womble, S.E. | Type: Conference Proceedings |
| Report number: LBNL-56382 | Year: 2005 |
| Title: Causes And Prevention Of Symptom Complaints In Office Buildings: Distilling The Experience Of Indoor Environmental Quality Investigators | Published in: Indoor Air 2005 Conference - The 10th International Conference on Indoor Air Quality and Climate, Volume 4(8), Pages 3500-3504. |
| Authors: Mendell, M., Brennan, T, Hathon, L., Odom, J.D., Offerman, F.J., Turk, B.H., Wallingford, K.M., Diamond, R.C., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: The goal of this project was to recommend empirically based strategies to prevent building-related symptoms in office buildings, for owners and managers. Ideas from six experienced building investigators were gathered and prioritized in a multi-day workshop. The top ranked problems identified were, in priority order: excessive building moisture, inadequate outdoor air, excessive dust, pollutant gases and odors, inadequate thermal control, and inadequate attention by management to indoor environments. Available findings in the scientific literature were generally consistent with these recommendations. The highest priority strategies recommended for preventing building-related symptoms were: managing water at building exteriors, operating ventilation systems per design intent, providing at least minimum ventilation rates, and maintaining indoor temperatures at 22°C ±1° (72°F ±2°). Despite the range of climates in which they worked, IEQ investigators showed considerable agreement, including top-ranking managing of water at building exteriors as a prevention strategy. Efficacy of these empirically based strategies generally has not been confirmed. | |
| Report number: LBNL-54475 | Year: 2005 |
| Title: Economic benefits of an economizer system: energy savings and reduced sick leave | Published in: ASHRAE Transactions, Volume 111, Pages 673-679. |
| Authors: Fisk, W.J., Seppanen, O., Faulkner, D., Huang, J. | Type: Journal Article |
| Abstract: Abstract: This study estimated the health, energy, and economic benefits of an economizer ventilation control system that increases outside air supply during mild weather to save energy. A model of the influence of ventilation rate on airborne transmission of respiratory illnesses was used to extend the limited data relating ventilation rate with illness and sick leave. An energy simulation model calculated ventilation rates and energy use versus time for an office building in Washington, D.C. with fixed minimum outdoor air supply rates, with and without an economiser. Sick leave rates were estimated with the disease transmission model. In the modelled 72-person office building, our analyses indicate that the economizer reduces energy costs by approximately $2000 and, in addition, reduces sick leave. The annual financial benefit of the decrease in sick leave is estimated to be between $6,000 and $16,000. This modelling suggests that economizers are much more cost effective than currently recognized. | |
| Report number: | Year: 2005 |
| Title: Health-related costs of indoor ETS, dampness and mold in the United States and in California | Published in: 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume I(3), Pages 308-313. |
| Authors: Fisk, W.J. | Type: Conference Proceedings |
| Report number: LBNL-54413 | Year: 2004 |
| Title: Associations between classroom CO2 concentrations and student attendance in Washington and Idaho | Published in: Indoor Air 2004, Volume 14, Pages 333-341. |
| Authors: Shendell, D.G, Prill,R., Fisk, W.J., Apte, M.G., Blake, D., Faulkner, D | Type: Journal Article |
| Abstract: Student attendance in American public schools is a critical factor in securing limited operational funding. Student and teacher attendance influence academic performance. Limited data exist on indoor air and environmental quality (IEQ) in schools, and how IEQ affects attendance, health, or performance. This study explored the association of student absence with measures of indoor minus outdoor carbon dioxide concentration (dCO2). Absence and dCO2 data were collected from 409 traditional and 25 portable classrooms from 22 schools located in six school districts in the states of Washington and Idaho. Study classrooms had individual heating, ventilation, and air conditioning (HVAC) systems, except two classrooms without mechanical ventilation. Classroom attributes, student attendance and school-level ethnicity, gender, and socioeconomic status (SES) were included in multivariate modeling. Forty-five percent of classrooms studied had short-term indoor CO2 concentrations above 1000 parts-per-million (ppm). A 1000 ppm increase in dCO2 was associated (p < 0.05) with a 0.5% to 0.9% decrease in annual average daily attendance (ADA), corresponding to a relative 10% to 20% increase in student absence. Annual ADA was 2% higher (p < 0.0001) in traditional than in portable classrooms. | |
| Report number: LBNL-55748 | Year: 2004 |
| Title: Summary of human responses to ventilation | Published in: Indoor Air (Supplement 7), Volume 14, Pages 102-118. |
| Authors: Seppanen, O., Fisk, W.J. | Type: Journal Article |
| Abstract: The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppänen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarised by Seppänen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppänen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarises the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually more complex and case specific. They are subject to occupational safety legislation and not discussed here. | |
| Report number: LBNL-55476 | Year: 2004 |
| Title: Commentary: Air-conditioning as a risk for increased use of health services | Published in: International Journal of Epidemiology, Volume 33, Pages 1123-1126. |
| Authors: Mendell, M. | Type: Journal Article |
| Report number: LBNL-55032 | Year: 2004 |
| Title: Worker Performance and Ventilation in a Call Center: Analyses of Work Performance Data for Registered Nurses | Published in: Indoor Air (Supplement 8), Volume 14, Pages 41-50. |
| Authors: Federspiel, C.C., Fisk, W.J., Price, P. N., Liu, G., Faulkner, D, DiBartolomeo, D.L., Sullivan, D.P., Lahiff, M. | Type: Journal Article |
| Abstract: We investigated the relationship between ventilation rates and individual work performance in a call center, and controlled for other factors of the indoor environment. We randomized the position of the outdoor air control dampers, and measured ventilation rate, differential (indoor minus outdoor) carbon dioxide (DCO2) concentration, supply air velocity, temperature, humidity, occupant density, degree of under-staffing, shift length, time of day, and time required to complete two different work performance tasks (talking with clients and post-talk wrap-up to process information). DCO2 concentrations ranged from 13 to 611 ppm. We used multi-variable regression to model the association between the predictors and the responses. We found that agents performed talk tasks fastest when the ventilation rate was highest, but that the relationship between talk performance and ventilation was not strong or monotonic. We did not find a statistically significant association between wrap-up performance and ventilation rate. Agents were slower at the wrap-up task when the temperature was high (>25.4 °C). Agents were slower at wrap-up during long shifts and when the call center was under-staffed. | |
| Report number: LBNL-53842 | Year: 2004 |
| Title: Associations of Indoor Carbon Dioxide Concentrations and Environmental Susceptibilities with Mucous Membrane and Lower Respiratory Building Related Symptoms in the BASE Study: Analyses of the 100 Building Dataset | Published in: Indoor Air (Suppl 8), Volume 14, Pages 127-34. |
| Authors: Erdmann, C.A., Apte, M.G. | Type: Journal Article |
| Abstract: Using the U.S. EPA 100 office-building BASE Study dataset, we conducted multivariate logistic regression analyses to quantify the relationship between indoor CO2 concentrations (dCO2) and mucous membrane (MM) and lower respiratory system (LResp) building related symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. In addition, we tested the hypothesis that certain environmentally-mediated health conditions (e.g., allergies and asthma) confer increased susceptibility to building related symptoms within office buildings. Adjusted odds ratios (ORs) for statistically significant, dose-dependant associations (p < 0.05) for dry eyes, sore throat, nose/sinus congestion, and wheeze symptoms with 100 ppm increases in dCO2 ranged from 1.1 to 1.2. These results suggest that increases in the ventilation rates per person among typical office buildings will, on average, reduce the prevalence of several building related symptoms by up to 70%, even when these buildings meet the existing ASHRAE ventilation standards for office buildings. Building occupants with certain environmentally-mediated health conditions are more likely to experience building related symptoms than those without these conditions (statistically significant ORs ranged from 2 to 11). | |
| Report number: LBNL-53586 | Year: 2003 |
| Title: Associations between classroom CO2 concentrations and student attendance | Published in: |
| Authors: Shendell, D.G., Prill, R., Fisk, W.J., Apte, M.G., Blake, D., Faulkner, D. | Type: Report |
| Abstract: Student attendance in American public schools is a critical factor in securing limited operational funding. Student and teacher attendance influence academic performance. Limited data exist on indoor air and environmental quality (IEQ) in schools, and how IEQ affects attendance, health, or performance. This study explored the association of student absence with measures of indoor minus outdoor carbon dioxide concentration (dCO2). Absence and dCO2 data were collected from 409 traditional and 25 portable classrooms from 14 schools located in six school districts in the states of Washington and Idaho. Study classrooms had individual heating, ventilation, and air conditioning (HVAC) systems, except two classrooms without mechanical ventilation. Classroom attributes, student attendance and school-level ethnicity, gender, and socioeconomic status (SES) were included in multivariate modeling. Forty-five percent of classrooms studied had short-term indoor CO2 concentrations above 1000 parts-per-million (ppm). A 1000 ppm increase in dCO2 was associated (p< 0.05) with a 0.5% to 0.9% decrease in annual average daily attendance (ADA), corresponding to a relative 10% to 20% increase in student absence. Outside air (ventilation) rates estimated from dCO2 and other collected data were not associated with absence. Annual ADA was 2% higher (p < 0.0001) in traditional than in portable classrooms. | |
| Report number: LBNL-53191 | Year: 2003 |
| Title: Cost benefit analysis of the night-time ventilative cooling in office building | Published in: Proceedings of the Healthy Buildings 2003 Conference, Singapore, Volume 3, Pages 394-399. |
| Authors: Seppänen, O., Fisk, W.J., Faulkner, D. | Type: Conference Proceedings |
| Abstract: The indoor temperature can be controlled with different levels of accuracy depending on the building and its HVAC system. The purpose of this study was to evaluate the potential productivity benefits of improved temperature control, and to apply the information for a cost-benefit analyses of night-time ventilative cooling, which is a very energy efficient method of reducing indoor daytime temperatures. We analyzed the literature relating work performance with temperature, and found a general decrement in work performance when temperatures exceeded those associated with thermal neutrality. These studies included physiological modelling, performance of various tasks in laboratory experiments and measured productivity at work in real buildings. The studies indicate an average 2% decrement in work performance per degree oC temperature rise, when the temperature is above 25 oC. When we use this relationship to evaluate night- time ventilative cooling, the resulting benefit to cost ratio varies from 32 to 120. | |
| Report number: LBNL-53193 | Year: 2003 |
| Title: A conceptual model to estimate cost effectiveness of the indoor environment improvements | Published in: Proceedings of the Healthy Buildings 2003 Conference, Singapore, Volume 3, Pages 368-374. |
| Authors: Seppänen, O., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: Macroeconomic analyses indicate a high cost to society of a deteriorated indoor climate. The few example calculations performed to date indicate that measures taken to improve IEQ are highly cost-effective when health and productivity benefits are considered. We believe that cost-benefit analyses of building designs and operations should routinely incorporate health and productivity impacts. As an initial step, we developed a conceptual model that shows the links between improvements in IEQ and the financial gains from reductions in medical care and sick leave, improved work performance, lower employee turn over, and reduced maintenance due to fewer complaints. | |
| Report number: LBNL-51761 | Year: 2003 |
| Title: Environmental Risk Factors and Work-Related Lower Respiratory Symptoms in 80 Office Buildings: An Exploratory Analysis of NIOSH Data | Published in: American Journal of Industrial Medicine, Volume 43, Pages 630-641. |
| Authors: Mendell, MJ, Naco, GN., Wilcox, TG., Sieber, WK. | Type: Journal Article |
| Abstract: Background: We evaluated relationships between lower respiratory symptoms and risk factors for microbiological contamination in office buildings. Methods: The National Institute for Occupational Safety and Health collected data from 80 office buildings during standardized indoor environmental health hazard evaluations. Present analyses included lower respiratory symptom-based outcome definitions and risk factors for potential microbiologic contamination. Multivariate logistic regression models for selected outcomes identified key risk factors. Results: Adjusted odds ratios (95% confidence intervals) for "at least three of four work-related lower respiratory symptoms" were, for debris in ventilation air intake, 2.0 (1.0- 3.9), and for poor drainage in air-conditioning drip pans, 2.6 (1.3-5.2). Adjusted associations with risk factors were consistently stronger for outcomes requiring both multiple symptoms and improvement away from work, and somewhat stronger among diagnosed asthmatics. Conclusions: Moisture and debris in ventilation systems, possibly by supporting microbiologic growth, may increase adverse respiratory effects, particularly among asthmatics. Data from more representative buildings are needed to confirm these findings. | |
| Report number: LBNL-53908 | Year: 2003 |
| Title: Association of Airborne Moisture-Indicating Microorganisms with Building-Related Symptoms and Water Damage in 100 U.S. Office Buildings: Analyses of the U.S. EPA BASE Data | Published in: |
| Authors: Mendell, M., lei, Q., Cozen, M., Shendel, D.G. | Type: Report |
| Abstract: Metrics of culturable airborne microorganisms for either total organisms or suspected harmful subgroups have generally not been associated with symptoms among building occupants. However, the visible presence of moisture damage or mold in residences and other buildings has consistently been associated with respiratory symptoms and other health effects. This relationship is presumably caused by adverse but uncharacterized exposures to moisture-related microbiological growth. In order to assess this hypothesis, we studied relationships in U.S. office buildings between the prevalence of respiratory and irritant symptoms, the concentrations of airborne microorganisms that require moist surfaces on which to grow, and the presence of visible water damage. | |
| Report number: LBNL-53964 | Year: 2003 |
| Title: Indices for IEQ and building-related symptoms | Published in: Indoor Air, Volume 13, Pages 364-368. |
| Authors: Mendell, M. | Type: Journal Article |
| Report number: LBNL-53192 | Year: 2003 |
| Title: Economizer system cost effectiveness: Accounting for the influence of ventilation rate on sick leave | Published in: Proceedings of the Healthy Buildings 2003 Conference, Singapore, Volume 3, Pages 361-367. |
| Authors: Fisk,W.J, Seppänen, O., Faulkner, D., Huang, J. | Type: Conference Proceedings |
| Abstract: This study estimated the health, energy, and economic benefits of an economizer ventilation control system that increases outside air supply during mild weather to save energy. A model of the influence of ventilation rate on airborne transmission of respiratory illnesses was used to extend the limited data relating ventilation rate with illness and sick leave. An energy simulation model calculated ventilation rates and energy use versus time for an office building in Washington, D.C. with fixed minimum outdoor air supply rates, with and without an economiser. Sick leave rates were estimated with the disease transmission model. In the modelled 72-person office building, our analyses indicate that the economizer reduces energy costs by approximately $2000 and, in addition, reduces sick leave. The financial benefit of the decrease in sick leave is estimated to be between $6,000 and $16,000. This modelling suggests that economizers are much more cost effective than currently recognized. | |
| Report number: LBNL-50046 | Year: 2002 |
| Title: Relationship of SBS-symptoms and ventilation system type in office buildings | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 3, Pages 437-442. |
| Authors: Seppänen, O., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: This paper provides a summary of current knowledge about the associations of ventilation system types in office buildings with sick building syndrome symptoms. Most studies completed to date indicate that relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms, by approximately 30% to 200%. In two of three analyses from a single study (assessments), symptom prevalences were also significantly higher in air-conditioned buildings than in buildings with simple mechanical ventilation and no humidification. The available data also suggest, with less consistency, an increase in risk of symptoms with simple mechanical ventilation relative to natural ventilation. The statistically significant associations of mechanical ventilation and air conditioning with SBS symptoms are much more frequent than expected from chance and also not likely to be a consequence of confounding by several potential personal, job, or building-related confounders. Multiple deficiencies in HVAC system design, construction, operation, or maintenance, including some of which cause pollutant emissions from HVAC systems, may contribute to the increases in symptom prevalences but other possible reasons remain unclear. | |
| Report number: LBNL-49566 | Year: 2002 |
| Title: Building-related risk factors and work-related lower respiratory symptoms in 80 office building | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 103-108. |
| Authors: Mendell, M.J., Naco, G.M. , Wilcox, T.G. , Sieber, W.K. | Type: Conference Proceedings |
| Abstract: We assessed building-related risk factors for lower respiratory symptoms in office workers. The National Institute for Occupational Safety and Health in 1993 collected data during indoor environmental health investigations of workplaces. We used multivariate logistic regression analyses to assess relationships between lower respiratory symptoms in office workers and risk factors plausibly related to microbiologic contamination. Among 2,435 occupants in 80 office buildings, frequent, work-related multiple lower respiratory symptoms were strongly associated, in multivariate models, with two risk factors for microbiologic contamination: poor pan drainage under cooling coils and debris in outside air intake. Associations tended to be stronger among those with a history of physician-diagnosed asthma. These findings suggest that adverse lower respiratory health effects from indoor work environments, although unusual, may occur in relation to poorly designed or maintained ventilation systems, particularly among previously diagnosed asthmatics. These findings require confirmation in more representative buildings. | |
| Report number: LBNL-48217 | Year: 2002 |
| Title: Indoor Particles and Symptoms Among Office Workers: Results from a Double-Blind Cross-Over Study | Published in: Epidemiology, Volume 13, Pages 296-304. |
| Authors: Mendell, M.J., Fisk, W.J., Petersen, M.R., Hines, C.J., Dong, M., Faulkner, D., Deddens, J.A., Ruder, A.M., Sullivan, D.P., Boeniger, M.F. | Type: Journal Article |
| Abstract: Background We studied the effects of removing small airborne particles in an office building without unusual contaminant sources or occupant complaints. Methods We conducted a double-blind crossover study of enhanced particle filtration in an office building in the Midwest U.S. in 1993. We replaced standard particle filters, in separate ventilation systems on two floors, with highly efficient filters, on alternate floors weekly over four weeks. Repeated-measures models were used to analyze data from weekly worker questionnaires and multiple environmental measurements. Results Bioaerosol concentrations were low. Enhanced filtration reduced concentrations of the smallest airborne particles by 94%. This reduction was not associated with reduced symptoms among the 396 respondents, but three performance-related mental states improved; for example, the confusion scale decreased (-3.7%; 95% confidence limits (CL) = -6.5, -0.9). Most environmental dissatisfaction variables also improved; eg, "stuffy" air, -5.3% (95% CL = -10.3, -0.4). Cooler temperatures within the recommended comfort range were associated with remarkably large improvement in most outcomes; for example, per 1ºC decrease, chest tightness decreased -23.4% (95% CL = -38.1, -8.7). Conclusions Benefits of enhanced filtration require assessment in buildings with higher particulate contaminant levels, in studies controlling for temperature effects. Benefits from lower indoor temperatures need confirmation. | |
| Report number: LBNL-51288 | Year: 2002 |
| Title: IEQ and the impact on building occupants | Published in: ASHRAE Journal, Volume 44, Pages 50-52. |
| Authors: Kumar, S., Fisk, W.J. | Type: Journal Article |
| Abstract: Research into indoor environmental quality (IEQ) and its effects on health, comfort, and performance of occupants is becoming an increasing priority as interest in high performance buildings and organizational productivity grows. Facility managers are interested in IEQ's close relationship to energy use in facilities. Employers, by providing excellent indoor environments, hope to enhance employee comfort and productivity, reduce absenteeism and health care costs, and reduce risk of litigation. The increasing interest in this field has put additional pressure on the research community as architects, engineers, facility managers, building investors, health officials, jurists, and the public seek practical guidelines on creating a safe, healthy, and comfortable indoor environment. Research on the relationships of IEQ to the health, comfort, and productivity of occupants has advanced considerably within the last decade. One of the primary goals of the Indoor Health and Productivity (IHP) Project is to communicate the results of this research, currently reported primarily in research publications, to building professionals. Consequently, the IHP project has worked with a peer review panel to select five key IHP papers and prepare summaries of these papers for publication in ASHRAE Journal. This article precedes those five summary articles, which will appear in the next five issues of the journal. This article summarizes the methodology employed to select the five papers, briefly summarizes the message of each paper, and discusses the practical implications for architects and engineers. More information about the objectives of the IHP project, results of research conducted under this project, and project sponsors and partners can be found at www.IHPCentral.org. The web site also has an online bibliography of approximately 900 papers on the topic of indoor health and productivity, drawn primarily from approximately 100 leading international journals and international conferences. | |
| Report number: LBNL-51289 | Year: 2002 |
| Title: IEQ and the impact on employee sick leave | Published in: ASHRAE Journal, Volume 44, Pages 97-98. |
| Authors: Kumar, S., Fisk, W.J. | Type: Journal Article |
| Abstract: When selecting minimum ventilation rates, employers need to strike a balance between the well-recognized energy costs of providing higher minimum ventilation rates and the expected, but less well quantified, health benefits from higher rate of ventilation. This is a summary of the paper by Milton et al. (2000) that found low employee sick leave associated with high ventilation rates in a set of buildings located in Massachusetts. A simple cost-benefit analysis is also presented. | |
| Report number: LBNL-49706 | Year: 2002 |
| Title: The role of Emerging Energy-Efficient Technology in Promoting Workplace Productivity and Health: Final Report | Published in: |
| Authors: Kumar, S., Fisk, W.J. | Type: Report |
| Abstract: When selecting minimum ventilation rates, employers need to strike a balance between the well-recognized energy costs of providing higher minimum ventilation rates and the expected, but less well quantified, health benefits from higher rate of ventilation. This is a summary of the paper by Milton et al. (2000) that found low employee sick leave associated with high ventilation rates in a set of buildings located in Massachusetts. A simple cost-benefit analysis is also presented. | |
| Report number: LBNL-49567 | Year: 2002 |
| Title: Do Indoor Environments in Schools Influence Student Performance? A Review of the Literature | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 802-807. |
| Authors: Heath, G.A., Mendell, M.J. | Type: Conference Proceedings |
| Abstract: The goal of this paper was to critically review available evidence on relationships between indoor environmental quality (IEQ) in schools and student performance. Because available evidence from schools was limited, the review expanded to include studies on direct relationships between the performance of children and adults and the indoor environments in schools, workplaces, residences, and controlled laboratory settings. The most persuasive available evidence suggests that some aspects of IEQ, including low ventilation rate and less daylight or light, may reduce the performance of occupants, including students in schools. Other evidence identifies additional possible influences, such as pollen and some carpets. Substantial limitations in the quantity and quality of available research findings suggest many questions for future study. Sufficient evidence is available to justify (1) actions to safeguard IEQ in schools and (2) the conduct of focused, well-designed research to help guide future policies and actions regarding IEQ in schools. | |
| Report number: LBNL-51724 | Year: 2002 |
| Title: Worker Performance and ventilation: analysis of time-series data for a group of call-center workers | Published in: Proceedings of the Indoor Air 2002, Monterey, CA, Volume 1, Pages 790-795. |
| Authors: Fisk, W.J., Price, P. N., Faulkner, D, Sullivan, D, Dibartolomeo, D., Federspiel, C., Liu, D.L., Lahiff, M. | Type: Conference Proceedings |
| Abstract: We investigated the relationship of ventilation rates with the performance of advice nurses working in a call center. Ventilation rates were manipulated; temperatures, humidities, and CO2 concentrations were monitored; and worker performance data, with 30-minute resolution, were collected. Multivariate linear regression was used to investigate the association of worker performance with building ventilation rate, or with indoor CO2 concentration (which is related to ventilation rate per worker). Results suggest that the effect of ventilation rate on worker performance in this call center was very small (probably less than 1%) or nil, over most of the range of ventilation rate (roughly 12 L s-1 to 48 L s-1 per person). However, there is some evidence of worker performance improvements of 2% or more when the ventilation rate per person was very high, as indicated by the indoor CO2 concentration exceeding the outdoor concentration by less than 75 ppm. | |
| Report number: LBNL-51382 | Year: 2002 |
| Title: Ventilation rates and health | Published in: ASHRAE Journal, Volume 44, Pages 56-58. |
| Authors: Fisk, W.J., M.J. Mendell | Type: Journal Article |
| Abstract: This article summarizes the review by Seppänen et al. (1999) of current literature on the relationship of ventilation rates and carbon dioxide concentrations in non-residential and non-industrial buildings (primarily offices) with the health of the building's occupants and with the occupants' perceptions of indoor air quality (IAQ). While ventilation rates do not directly affect occupant health or perception outcomes, they affect indoor environmental conditions including air pollutant concentrations that, in turn, may modify the occupants' health or perceptions. The review aims to provide a better scientific basis for setting health-related ventilation standards. Space constraints prohibit a detailed description of both ventilation rate and carbon dioxide concentration studies; therefore, this summary focuses primarily on the ventilation rate studies. | |
| Report number: LBNL-51381 | Year: 2002 |
| Title: How IAQ affects health, productivity | Published in: ASHRAE Journal, Volume 44, Pages 56, 58-60. |
| Authors: Fisk, W.J. | Type: Journal Article |
| Abstract: This article, a summary of Fisk (2000a, 2000b), estimates the nationwide improvements in health and productivity potentially attainable by providing better indoor environmental quality (IEQ) in U.S. buildings. Estimates include the potential reductions in three categories of health effects, the associated economic benefits, and the potential direct improvements in productivity not mediated through health. Expected costs and benefits of improving IEQ are compared, with a brief discussion of energy implications. | |
| Report number: LBNL-50124 | Year: 2002 |
| Title: Worker performance and ventilation: Analyses of individual data for call-center workers | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 796-801. |
| Authors: Federspiel, C.C., Liu, G., Lahiff, M., Faulkner, D., Dibartolomeo, D.L., Fisk, W.J., Price, P.N., Sullivan, D.P. | Type: Conference Proceedings |
| Abstract: We investigated the relationship between ventilation rates and work performance in a call center. We randomized the ventilation controls and measured ventilation rate, differential carbon dioxide (?CO2) concentration, temperature, humidity, occupant density, degree of under-staffing, shift length, time of day, and time required to complete two different work performance tasks (talk and wrap-up). ?CO2 concentrations ranged from 13 to 611 ppm. We used multi-variable regression to model the association between the predictors and the responses. We found that agents performed talk tasks fastest when the ventilation rate was highest, but that the relationship between talk performance and ventilation was not monotone. We did not find a statistically significant association between wrap-up performance and ventilation. At high temperatures agents were slower at both the talk and wrap-up tasks. Agents were slower at wrap-up during long shifts and when the call center was under-staffed. | |
| Report number: LBNL-49584 | Year: 2002 |
| Title: Indoor carbon dioxide concentrations and SBS symptoms in office buildings revisited: Analyses of the 100 building BASE Study dataset | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 3, Pages 443-448. |
| Authors: Erdmann, C.A., Steiner, K.C., Apte, M.G. | Type: Conference Proceedings |
| Abstract: In previously published analyses of the 41-building 1994-1996 USEPA Building Assessment Survey and Evaluation (BASE) dataset, higher workday time-averaged indoor minus outdoor CO2 concentrations (dCO2) were associated with increased prevalence of certain mucous membrane and lower respiratory sick building syndrome (SBS) symptoms, even at peak dCO2 concentrations below 1,000 ppm. For this paper, similar analyses were performed using the larger 100-building 1994-1998 BASE dataset. Multivariate logistic regression analyses quantified the associations between dCO2 and the SBS symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. Adjusted dCO2 prevalence odds ratios for sore throat and wheeze were 1.17 and 1.20 per 100-ppm increase in dCO2 (p <0.05), respectively. These new analyses generally support our prior findings. Regional differences in climate, building design, and operation may account for some of the differences observed in analyses of the two datasets. | |
| Report number: LBNL-47457 | Year: 2001 |
| Title: Association of ventilation system type with SBS symptoms in office workers | Published in: Indoor Air, Volume 12, Pages 98-112. |
| Authors: Seppänen, O., Fisk, W.J. | Type: Journal Article |
| Report number: | Year: 2001 |
| Title: Letters to the Editor | Published in: Journal of the Air and Waste Management Association, Volume 50, Pages 322. |
| Authors: Apte, M G., Lefohn, A.S. | Type: Journal Article |
| Report number: LBNL-48219 | Year: 2000 |
| Title: Research needs and approaches pertaining to the indoor climate and productivity | Published in: Healthy Buildings 2000, Volume 2, Pages 327-332. |
| Authors: Wyon, D., Fisk, W.J., Rautio, S., O. Seppanen, M. Tuomainen, J. Sateri | Type: Conference Proceedings |
| Abstract: The indoor environment affects the health, comfort and performance of occupants. All three are important, but the cost of improved design, operation, maintenance and energy use in buildings must usually be justified in terms of the expected effects on productivity. While there is no doubt that effects on health, comfort and performance translate into effects on productivity, there is an urgent need to discover which of the hypothesised mechanisms of cause and effect are valid to quantify how much each mechanism affects productivity in different work situations, and to validate predictions in the field. | |
| Report number: LBNL-48246 | Year: 2000 |
| Title: Association of ventilation rates with health and other responses in commercial and institutional buildings | Published in: Healthy Buildings 2000 Conference, Pages 1-8. |
| Authors: Seppanen, O., Fisk, B., Olli Seppanen, Marianna Tuomainen, Jorma Sateri | Type: Conference Proceedings |
| Report number: LBNL-48218 | Year: 2000 |
| Title: Review of health and productivity gains from better IEQ | Published in: Healthy Buildings 2000, Volume 4, Pages 23-24. |
| Authors: Fisk, W.J., O. Seppanen, M. Tuomainen, J. Sateri | Type: Conference Proceedings |
| Abstract: The available scientific data suggest that existing technologies and procedures can improve indoor environmental quality (IEQ) in a manner that significantly increases productivity and health. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billion from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment. | |
| Report number: LBNL-45484 | Year: 2000 |
| Title: Health and productivity gains from better indoor environments and their relationship with building energy efficiency | Published in: Annual Review of Energy and the Environment, Volume 25, Pages 537-566. |
| Authors: Fisk, W.J. | Type: Journal Article |
| Report number: LBNL-42123 | Year: 2000 |
| Title: Estimates of potential nationwide productivity and health benefits from better indoor environments: An update | Published in: Chapter 4 in Indoor Air Quality Handbook. |
| Authors: Fisk, W.J., Spengler, J.D., Samet, J.M., McCarthy, J.F. | Type: Book Section |
| Report number: LBNL-45019 | Year: 2000 |
| Title: Indoor carbon dioxide concentrations and SBS in office workers | Published in: Proceedings of the Healthy Buildings 2000 Conference, Helsinki, Finland, Volume 1, Pages 133-138. |
| Authors: Apte, M., Fisk, W., Daisey, J. | Type: Conference Proceedings |
| Report number: LBNL-44385 | Year: 2000 |
| Title: Associations between Indoor CO2 Concentrations and Sick Building Syndrome Symptoms in US Office Buildings: An Analysis of the 1994-1996 BASE Study Data | Published in: Indoor Air, Volume 10, Pages 246-257. |
| Authors: Apte, M., Fisk, B., Daisey, J. | Type: Journal Article |
| Report number: LBNL-43334 | Year: 1999 |
| Title: Association of ventilation rates and CO2 -concentrations with health and other responses in commercial and institutional buildings | Published in: Indoor Air, Volume 9, Pages 226-252. |
| Authors: Seppänen, O.A., Fisk, W.J., Mendell, M.J. | Type: Journal Article |
| Report number: LBNL-42221 | Year: 1999 |
| Title: Effects on Occupants of Enhanced Particle Filtration in a Non-Problem Office Environment: A Double-Blind Crossover Intervention Study | Published in: The American Journal of Industrial Medicine, Volume Supp 1, Pages 55-57. |
| Authors: Mendell, M. J., Fisk, W. J., Petersen, M., Hines, C. J., Faulkner, D., Deddens, J. A., Dong, M. X., Ruder, A. M., Sullivan, D., Boeniger, M. F. | Type: Journal Article |
| Report number: LBNL-42698 | Year: 1999 |
| Title: VOCs and "Sick Building Syndrome": Application of a New Statistical Approach for SBS Research to U.S. EPA BASE Study Data | Published in: Proceedings of the Indoor Air '99, Edinburgh, Scotland, Volume 1, Pages 117-112. |
| Authors: Apte, M.G. | Type: Conference Proceedings |
| Report number: LBNL-41849 | Year: 1998 |
| Title: Potential Nationwide Improvements in Productivity and Health from Better Indoor Environments | Published in: Proceedings of the 1998 ACEEE Summer Study on Energy and Efficiency in Buildings, Pacific Grove, CA, Volume 8, Pages 85-97. |
| Authors: Fisk, W.J., A.H. Rosenfeld | Type: Conference Proceedings |
| Report number: | Year: 1998 |
| Title: The indoor environment -- productivity and health -- and $$$ | Published in: Planning for Energy and the Environment, Volume 17, Pages 53-57. |
| Authors: Fisk, W.J., Rosenfeld, A.H. | Type: Journal Article |
| Report number: LBNL-41546 | Year: 1998 |
| Title: The healthy building intervention study: Objectives, methods and results of Selected Environment Measurements | Published in: |
| Authors: Fisk, W.J., D. Faulkner, D. Sullivan, M. Dong, C. Dabrowski, Jr., J.J. Thomas, M.J. Mendell, C.J. Hines, A. Ruder, M. Boeniger | Type: Report |
| Report number: LBNL-39596 | Year: 1997 |
| Title: Estimates of Improved Productivity and Health from Better Indoor Environments | Published in: Indoor Air, Volume 7, Pages 158-172. |
| Authors: Fisk, W.J., Rosenfeld, A.H. | Type: Journal Article |
| Report number: LBNL-42555 | Year: 1996 |
| Title: Elevated symptom prevalence associated with ventilation type in office buildings: findings from the California Healthy Building Study | Published in: Epidemiology, Volume 7, Pages 583-589. |
| Authors: Mendell, MJ, Fisk, WJ, Deddens, JA, Seavey, WG, Smith AH, Smith DF, Hodgson, AT, Daisey JM, Goldman L. | Type: Journal Article |
| Report number: LBNL-37652 | Year: 1995 |
| Title: Development of New VOC Exposure Metrics and their Relationship to "Sick Building Syndrome" Symptoms | Published in: Environmental Health Sciences, School of Public Health, Pages 223. |
| Authors: Ten Brinke, J., Dr. Joan M. Daisey, Prof. Catherine P. Koshland | Type: Thesis |
| Report number: LBNL-260E | Year: 2008 |
| Title: A Pilot study of the accuracy of CO2 sensors in commercial buildings | Published in: IAQ 2007 Healthy and Sustainable Buildings. |
| Authors: Fisk, W.J., Faulkner, D., Sullivan, D.P. | Type: Conference Proceedings |
| Abstract: Carbon dioxide (CO2) sensors are often deployed in commercial buildings to obtain CO2 data that are used to automatically modulate rates of outdoor air supply. The goal is to keep ventilation rates at or above design requirements and to save energy by avoiding ventilation rates exceeding design requirements. However, there have been many anecdotal reports of poor CO2 sensor performance in actual commercial building applications. This study evaluated the accuracy of 44 CO2 sensors located in nine commercial buildings to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. CO2 measurement errors varied widely and were sometimes hundreds of parts per million. Despite its small size, this study provides a strong indication that the accuracy of CO2 sensors, as they are applied and maintained in commercial buildings, is frequently less than needed to measure typical values of maximum one-hour-average indoor-outdoor CO2 concentration differences with less than a 20% error. Thus, we conclude that there is a need for more accurate CO2 sensors and/or better sensor maintenance or calibration procedures. | |
| Report number: LBNL-255E | Year: 2008 |
| Title: Can sorbent-based gas phase air cleaning for VOCs substitute for ventilation in commercial buildings? | Published in: IAQ 2007 Healthy and Sustainable Buildings. |
| Authors: Fisk, W.J. | Type: Conference Proceedings |
| Abstract: This paper reviews current knowledge about the suitability of sorbent-based air cleaning for removing volatile organic compounds (VOCs) from the air in commercial buildings, as needed to enable reductions in ventilation rates and associated energy savings. The principles of sorbent air cleaning are introduced, criteria are suggested for sorbent systems that can counteract indoor VOC concentration increases from reduced ventilation, major findings from research on sorbent performance for this application are summarized, and related priority research needs are identified. Major conclusions include: sorbent systems can remove a broad range of VOCs with moderate to high efficiency, sorbent technologies perform effectively when challenged with VOCs at the low concentrations present indoors, and there is a large uncertainty about the lifetime and associated costs of sorbent air cleaning systems when used in commercial buildings for indoor VOC control. Suggested priority research includes: experiments to determine sorbent system VOC removal efficiencies and lifetimes considering the broad range and low concentration of VOCs indoors; evaluations of in-situ regeneration of sorbents; and an updated analysis of the cost of sorbent air cleaning relative to the cost of ventilation. | |
| Report number: LBNL-53E | Year: 2008 |
| Title: Commentary on Predictive Models of Control Strategies involved in Containing Indoor Airborne Infections | Published in: Indoor Air, Volume 16, Pages 469-481. |
| Authors: Fisk, W.J. | Type: Journal Article |
| Report number: LBNL-63006 | Year: 2007 |
| Title: Providing better indoor environmental quality brings economic benefits | Published in: REHVA World Congress - CLIMA 2007. |
| Authors: Fisk, W.J., Seppanen, O. | Type: Conference Proceedings |
| Abstract: This paper summarizes the current scientific evidence that improved indoor environmental quality can improve work performance and health. The review indicates that work and school work performance is affected by indoor temperature and ventilation rate. Pollutant source removal can sometimes improve work performance. Based on formal statistical analyses of existing research results, quantitative relationships are provided for the linkages of work performance with indoor temperature and outdoor air ventilation rate. The review also indicates that improved health and related financial savings are obtainable from reduced indoor tobacco smoking, prevention and remediation of building dampness, and increased ventilation. Example cost-benefit analyses indicate that many measures to improve indoor temperature control and increase ventilation rates will be highly cost effective, with benefit-cost ratios as high as 80 and annual economic benefits as high as $700 per person. | |
| Report number: LBNL-60291 | Year: 2006 |
| Title: Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities | Published in: Healthy Buildings 2006 Conference, Pages A-34. |
| Authors: Morrison, G.C., Corsi, R.L., Destaillats, H., Nazaroff, W., Wells, J.R. | Type: Conference Proceedings |
| Report number: LBNL-59329 | Year: 2006 |
| Title: Causes and prevention of symptom complaints in office buildings: Distilling the experience of indoor environmental quality investigators | Published in: Facilities 2006, Volume 24, Pages 436-444. |
| Authors: Mendell, M., Brennan, T, Hathon, L., Odom, J.D., Offerman, F.J., Turk, B.H., Wallingford, K.M., Diamond, R., Fisk, B. | Type: Journal Article |
| Abstract: ABSTRACT Purpose The goal of this project was to develop, based on the experience of those who investigate health complaints in buildings, practical strategies for preventing building-related symptoms in office buildings, suitable for use by those who own, lease, or manage office space. Methodology/approach Ideas from six experienced building investigators on primary causes and key prevention strategies were gathered and prioritized through consensus and voting in a structured, multi-day workshop. Findings The top ranked problems identified were, in priority order: excessive building moisture, inadequate outdoor air, dust on indoor surfaces, indoor gases and odors, inadequate thermal control, and inadequate attention by management to indoor environments. The highest priority strategies recommended for preventing building-related symptoms were: managing moisture at building exteriors, operating ventilation systems per design intent, providing at least minimum ventilation rates, and maintaining indoor temperatures at 72°F ±2°. Findings in the scientific literature were generally consistent with these recommendations. Research limitations/implications Findings reported here result from a subjective synthesis of empirical knowledge, not from scientific research, and have not yet been scientifically confirmed. Still, IEQ investigators showed considerable agreement on the most important causes of symptom complaints in office buildings and the key methods for preventing these problems. Practical implications These recommendations, generally consistent with available research findings, provide useful practical guidelines for those who own, manage or maintain office buildings. Originality/value The empirical knowledge of practitioners, concentrated and synthesized here, offers more guidance for choosing health-protective strategies in office buildings than current science. | |
| Report number: LBNL-58694 | Year: 2005 |
| Title: National Expenditures for IAQ Problem Prevention or Mitigation | Published in: |
| Authors: Levin, H. | Type: Report |
| Abstract: The objectives of this study were to develop an initial semi-quantitative estimate of costs of indoor air quality problem prevention, mitigation, and remediation activities in U.S. buildings and to provide useful information for a more comprehensive and accurate survey. This is intended to be more of a map of the territory rather than a precise cost estimate. | |
| Report number: LBNL-57277 | Year: 2005 |
| Title: Improving Indoor Environmental Quality and Energy Performance of Modular Classroom HVAC Systems | Published in: Proceedings of Sustainable Buildings 2005 Conference, Pages 1432-1437. |
| Authors: Apte, M G., Spears, M., Lai, C.M., Shendel, D.G. | Type: Conference Proceedings |
| Abstract: The factory-built relocatable classroom (RC) is a dominant force in the school facility construction industry in the United States (U.S.) and elsewhere. It is estimated that there are approximately 650,000 RCs currently occupied in the U.S., housing about 16 million students. RCs receive public attention due to complaints about poor indoor environmental quality (IEQ). Both measured data and anecdotal evidence in California have suggested excessive acoustical noise from heating, ventilation, and air conditioning (HVAC) equipment as a central factor leading to degraded IEQ. In the U.S., RCs are typically equipped with unitary exterior wall-mount HVAC systems, and interior acoustical noise due to structural and airborne transmission can reach levels of about 58dB(A) with compressor cycling, under unoccupied conditions. Due to these noise levels teachers often simply choose to turn off the HVAC, leading to inadequate ventilation, as well as poor thermal conditioning, and thus to poor indoor air quality. Elevated levels of carbon dioxide and volatile organic compounds including formaldehyde are common. We discuss the acoustic component of our efforts to develop and test energy efficient HVAC systems that address the ventilation, controls, and acoustic requirements necessary to ensure high quality indoor environments in RCs. | |
| Report number: LBNL-58824 | Year: 2005 |
| Title: Improving Ventilation and Saving Energy: Relocatable Classroom Field Study Interim Report | Published in: |
| Authors: Apte, M G., Faulkner, D, Hodgson, A., Hotchi, T., Spears, M., Sullivan, D, Wang, D. | Type: Report |
| Abstract: The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many classrooms are under-ventilated, and public concerns about indoor environmental quality in classrooms. This report presents an interim status update and preliminary findings from energy and indoor environmental quality (IEQ) measurements in sixteen relocatable classrooms in California. The field study includes measurements of HVAC energy use, ventilation rates, and IEQ conditions. Ten of the classrooms were equipped with a new HVAC technology and six control classrooms were equipped with a standard HVAC system. Energy use and many IEQ parameters have been monitored continuously, while unoccupied acoustic measurements were measured in one of four planned seasonal measurement campaigns. Continuously monitored data are remotely accessed via a LonWorks® network and stored in a relational database at LBNL. Preliminary results are presented here. | |
| Report number: LBNL-57172 | Year: 2005 |
| Title: Improving Relocatable Classroom HVAC For Improved IEQ And Energy Efficiency | Published in: Indoor Air 2005 Conference - The 10th International Conference on Indoor Air Quality and Climate, Volume 1(7), Pages 1121-1125. |
| Authors: Apte, M G., Faulkner, D, Fisk, W.J., Hodgson, A.T., Hotchi, T., Lai, C.M., Spears, M., Sullivan, D.P., Wang, D. | Type: Conference Proceedings |
| Abstract: Relocatable classrooms (RCs) in California (CA) alone house about 2 million students in more than 80,000 structures. These buildings are typically under-ventilated, often due to low HVAC utilization because of excessive HVAC acoustic noise, and because when automatically operated they only ventilate during thermal conditioning. It can be predicted that such conditions affect the quality education and student health. These systems are also energy inefficient and peak-load demanding. With a manufacturer of wall-mounted HVAC systems, we are developing a new system addressing these problems. Design goals include a =30% increase the seasonal energy efficiency ratio (SEER) over the current SEER 10 system, noise reduction =45 dB(A), continuous ventilation meeting CA State code requirements (e.g. ASHRAE 62.1 ventilation standard of 7 l s-1 per occupant and a pre-occupancy air purge). The prototype was operated in an RC test-bed to characterize its performance from the standpoint of ventilation, and thermal control, acoustical noise, and energy consumption. Ten of the new HVAC systems are also being monitored for one year in matched pairs with the current standard HVAC systems after being installed in identical occupied RCs in four schools in Northern and Southern CA. Continuous measurements include indoor and outdoor carbon dioxide, temperature, relative humidity, and HVAC power consumption. Additionally, acoustical noise levels; thermal comfort; and concentrations of volatile organic compounds, formaldehyde and acetaldehyde, and ozone will be measured on a regular schedule throughout the study year. Daily classroom occupancy rates will be collected from the class records. The potential IEQ and energy savings benefits of the system will be presented from preliminary data collected in the field. | |
| Report number: LBNL-55774 | Year: 2004 |
| Title: Indoor Air Pollutants Part 2: Description of sources and control/mitigation measures | Published in: AIVC - Ventilation Information Paper, Volume 7, Pages 1-7. |
| Authors: Levin, H. | Type: Journal Article |
| Abstract: This Ventilation Information Paper (VIP) addresses the sources of pollutants and effective measures to control them or to mitigate their impacts on occupants and building contents. The most effective means to control indoor air pollution is through reduction or elimination of pollution sources. Indoor pollutants originate both within the building and from outside. The first step in controlling the sources of indoor air pollution is to identify them. Building materials, occupants and their activities, and equipment and appliances can all be sources of indoor pollutants. Once the sources have been identified, control strategies can be developed and implemented. Appropriate ventilation strategies can reduce concentrations of pollutants that can't be eliminated by source control. Air cleaning and filtration can reduce the concentrations of contaminants in buildings where ventilation systems recirculate air within the building. | |
| Report number: LBNL-54859 | Year: 2004 |
| Title: Designing Building Systems to Save Energy and Improve Indoor Environments: A Practical Demonstration | Published in: 2004 ACEEE Summer Study on Energy Efficiency in Buildings, Volume 3, Pages 13-27. |
| Authors: Apte, M G., Hodgson, A.T, Shendel, D.G., Rainer, L.I., Hoeschele, M.A. | Type: Conference Proceedings |
| Abstract: Building design concepts that focus on energy efficiency may conflict with those intended to provide excellent indoor environmental quality (IEQ). Careful selection of a heating, ventilating, and air-conditioning (HVAC) system, and low-emission interior finish materials, can result in winwin designs that minimize tradeoffs between energy and IEQ. We demonstrated energy and IEQ benefits in four new relocatable classrooms (RCs) monitored in two climate regions of California for one year. We used a case-crossover experimental design to compare energy and IEQ characteristics of a hybrid HVAC system that provides continuous ventilation (indirect-direct evaporative cooler with high-efficiency hydronic gas heat) to a standard heat pump system. Additionally, we explored the IEQ benefits of measurement-based selection of interior finish materials with low emissions of health-relevant volatile organic compounds (VOCs) including formaldehyde. Monitored data were used to calibrate DOE-2 models that simulated California-wide energy saving potential of RCs employing energy efficient building components including the hybrid HVAC system. IEQ monitoring results from our field investigation indicated that VOC concentration reductions, typically 50% or more, were achieved through improved ventilation while simultaneously average cooling and heating energy costs were reduced by 50% and 30%, respectively. Incremental annual California-wide energy impacts from installation of hybrid HVAC systems in 4,000 new RCs were projected to be: 5,975 MWh of electricity savings; 23.8 MW winter and 13.1 MW summer peak electric load reduction; 1,025 MBtu natural gas consumption from switch to gas heating; 50,931 MBtu source energy reduction; and a combined school district annual operating cost reduction of $880,900. | |
| Report number: LBNL-56527 | Year: 2004 |
| Title: Classroom HVAC: Improving ventilation and saving energy field study plan | Published in: |
| Authors: Apte, M G., Faulkner, D, Hodgson, A., Sullivan, D | Type: Report |
| Abstract: The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms (CRs) with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many CRs are under-ventilated, and public concerns about indoor environmental quality in CRs. This document provides a summary of the detailed plans developed for the field study that will take place in 2005 to evaluate the energy and IAQ performance of a new classroom HVAC technology. The field study will include measurements of HVAC energy use, ventilation rates, and IEQ conditions in 10 classrooms with the new HVAC technology and in six control classrooms with a standard HVAC system. Energy use and many IEQ parameters will be monitored continuously, while other IEQ measurements will be performed seasonally. Continuously monitored data will be remotely accessed via a LonWorks network. Instrument calibration plans that vary with the type of instrumentation used are established. Statistical tests will be employed to compare energy use and IEQ conditions with the new and standard HVAC systems. Strengths of this study plan include the collection of real time data for a full school year, the use of high quality instrumentation, the incorporation of many quality control measures, and the extensive collaborations with industry that limit costs to the sponsors. | |
| Report number: LBNL-53804 | Year: 2003 |
| Title: Assessment of organic compound exposures, thermal comfort parameters, and HVAC system-driven air exchange rates in public school portable classrooms in California | Published in: |
| Authors: Shendell, D.G. | Type: Report |
| Abstract: The prevalence of prefabricated, portable classrooms (portables, relocatables, RCs) has increased due to class size reduction initiatives and limited resources. Classroom mechanical wall-mount heating, ventilation, and air conditioning (HVAC) systems may function improperly or not be maintained; lower ventilation rates may impact indoor air and environmental quality (IEQ). Materials in portables may off- gas volatile organic compounds (VOCs), including formaldehyde, as a function of age, temperature, and humidity. For a pilot study, public K-12 schools located in or serving target areas within five Los Angeles County communities were identified. In two communities where school districts (SD) consented, 1-3 randomly selected portables, one newer and one older, and one main building control classroom from each participating school were included. Sampling was conducted over a five-day school week in the cooling and heating seasons, or repeated twice in the cooling season. Measurements included passive samplers for VOCs, formaldehyde and acetaldehyde, and air exchange rate (AER) calculation; indoor air temperature and humidity; technician walk-through surveys; an interview questionnaire about HVAC system operation and maintenance (O&M). For an intervention study evaluating advanced HVAC technologies in comparison to the common conventional technology, and materials for source reduction of VOCs, four RC were manufactured and located in pairs at two schools in two recruited Northern California SD in different climate zones. RCs were built with the two HVAC systems, cabinetry and conduit for monitoring equipment, and standard or advanced interior finish materials. Each RC was its own control in a case-crossover design -- HVAC systems alternately operated for 1-2 week intervals in the 2001-02 school year, with IEQ monitoring including aldehyde and indoor air temperature and humidity data. Measured classroom AER were low, formaldehyde concentrations were below the state indoor air guideline "target level," and concentrations of most target VOCs were low. O&M questionnaire results suggested insufficient training and communication between custodians and SD offices concerning HVAC systems. Future studies should attempt larger sample sizes and cover larger geographical areas but continue to assess multiple IEQ parameters during occupied hours. Teachers, custodians, and SD staff must be educated on the importance of adequate ventilation with filtered outdoor air. | |
| Report number: LBNL-48287 | Year: 2003 |
| Title: Indoor air quality, ventilation and health symptoms in schools: An analysis of existing information | Published in: Indoor Air, Volume 13, Pages 53-64. |
| Authors: Daisey, J., Apte, M G., Angell, W.J. | Type: Journal Article |
| Abstract: We reviewed the literature on indoor air quality (IAQ), ventilation, and building-related health problems in schools and identified commonly reported building-related health symptoms involving schools until 1999. We collected existing data on ventilation rates, carbon dioxide (CO2) concentrations and symptom-relevant indoor air contaminants, and evaluated information on causal relationships between pollutant exposures and health symptoms. Reported ventilation and CO2 data strongly indicate that ventilation is inadequate in many classrooms, possibly leading to health symptoms. Adequate ventilation should be a major focus of design or remediation efforts. Total volatile organic compounds, formaldehyde and microbiological contaminants are reported. Low formaldehyde concentrations were unlikely to cause acute irritant symptoms (<0.05 ppm), but possibly increased risks for allergen sensitivities, chronic irritation, and cancer. Reported microbiological contaminants included allergens in deposited dust, fungi and bacteria. Levels of specific allergens were sufficient to cause symptoms in allergic occupants. Measurements of airborne bacteria and airborne and surface fungal spores were reported in schoolrooms. Asthma and "sick building syndrome" symptoms are commonly reported. The few studies investigating causal relationships between health symptoms and exposures to specific pollutants suggest that such symptoms in schools are related to exposures to volatile organic compounds (VOCs), molds and microbial VOCs, and allergens. | |
| Report number: LBNL-52690 | Year: 2003 |
| Title: Simultaneous Energy Savings and IEQ Improvements in Relocatable Classrooms | Published in: |
| Authors: Apte, M.G., Hodgson, A.T., Shendell, D.G., Dibartolomeo, D., Hotchi, T., Lee, S.M., Liff, S.M., Rainer, L.I., Sullivan, D.P., Fisk, W.J.. | Type: Report |
| Abstract: Relocatable classrooms (RCs) are commonly used by school districts with changing demographics and enrollment sizes. We designed and constructed four energy-efficient RCs for this study to demonstrate technologies with the potential to simultaneously improve energy efficiency and indoor environmental quality (IEQ). Two were installed at each of two school districts, and energy use and IEQ parameters were monitored during occupancy. Two RCs (one per school) were finished with materials selected for reduced emissions of toxic and odorous volatile organic compounds (VOCs). Each had two HVAC systems, operated on alternate weeks, consisting of a standard heat-pump system and an indirect-direct evaporative cooling (IDEC) system with gas-fired hydronic heating. The IDEC system provides continuous outside air ventilation at "15 CFM (7.5 L s-1) person-1, efficient particle filtration while using significantly less energy for cooling. School year long measurements included: carbon dioxide (CO2), particles, VOCs, temperature, humidity, thermal comfort, noise, meteorology, and energy use. IEQ monitoring results indicate that important ventilation-relevant indoor CO2 and health-relevant VOC concentration reductions were achieved while average cooling and heating energy costs were simultaneously reduced by 50% and 30%, respectively. | |
| Report number: LBNL-54870 | Year: 2003 |
| Title: Simultaneous Improvements in Relocatable Classrooms | Published in: ASHRAE IAQ Applications, Pages 7-10. |
| Authors: Apte, M G., Hodgson, A., Shendel, D.G., Dibartolomeo, D., Hotchi, T., Lee, S-M, Liff, S., Rainer, L., Sullivan, D, Fisk, W.J. | Type: Journal Article |
| Report number: LBNL-50419 | Year: 2002 |
| Title: A compilation of papers for the Indoor Air 2002 Conference in memory of Joan M. Daisey | Published in: |
| Authors: IED Staff | Type: Report |
| Abstract: No Abstract available | |
| Report number: LBNL-51101 | Year: 2002 |
| Title: Final methodology for a field study of indoor environmental quality and energy efficiency in new relocatable classrooms in Northern California | Published in: |
| Authors: Shendell, D.G., DiBartolomeo, D. , Fisk, W.J., Hodgson, A.T., Hotchi, T. , Lee, S. M., Sullivan, D.P. , Apte, M.G., Rainer, L.I. | Type: Report |
| Abstract: The prevalence of relocatable classrooms (RCs) at schools is rising due to federal and state initiatives to reduce K-3 class size, and limited capital resources. Concerns regarding inadequate ventilation and indoor air and environmental quality (IEQ) in RCs have been raised. Adequate ventilation is an important link between improved IEQ and energy efficiency for schools. Since students and teachers spend the majority of a 7-8 hour school day inside classrooms, indoor contaminant concentrations are assumed to drive personal school-day exposures. We conducted a demonstration project in new relocatable classrooms (RCs) during the 2001-02 school year to address these issues. Four new 24' x 40' (960 ft2) RCs were constructed and sited in pairs at an elementary school campus in each of two participant school districts (SD) in Northern California. Each RC was equipped with two heating, ventilation, and air conditioning (HVAC) systems, one per module. The two HVAC systems were a standard heat pump with intermittent 25-50% outdoor air ventilation and an energy-efficient advanced system, based on indirect-direct evaporative cooling with an integrated natural gas-fired hydronic heating loop and improved particle filtration, providing continuous 100% outdoor air ventilation at = 15 ft3 min-1 occupant-1. Alternate carpets, wall panels, and ceiling panels were installed in two classrooms - one in each pair - based on the results of a laboratory study of VOC emissions from standard and alternate materials. Numerous IEQ and outdoor air quality and meteorological parameters were measured either continuously over the school year or as integrated school day samples during the fall cooling and winter heating seasons. Details of the RC designs, the field monitoring methodology including handling, storage, transport and management of chemical samples and data, and analyses to be conducted are presented. | |
| Report number: LBNL-50377 | Year: 2002 |
| Title: Building effective partnerships to conduct school indoor environmental quality assessments and interventions. Submitted as Field Action Report to American Journal of Public Health, July 19, 2002 | Published in: |
| Authors: Shendell, D.G., Apte, M.G., Kim, J. , Smorodinsky, S. | Type: Report |
| Abstract: Public, private, government, and university stakeholders have focused increasing attention on children's environmental health. Priority areas include healthy school environments; susceptibilities of children to environmental factors and associated illness; and, understanding exposure to biological, chemical, and physical agents. As multidisciplinary teams, we have conducted studies and intervention demonstrations in California public schools. A common theme among them was a "partnership," the collaboration between stakeholders from the aforementioned sectors. Federal funding and local bond measures for planning, maintenance, and modernization of school facilities have recently been authorized. Therefore, beneficial "partnerships" should be established to conduct needed IEQ, environmental health, and productivity research, development and demonstration. This field action report describes benefits for stakeholders and five strategies for future effective collaborations. | |
| Report number: Abstract (no LBNL number) | Year: 2002 |
| Title: Assessment of Noise Exposures in New Relocatable Classrooms with Standard and Advanced HVAC Systems | Published in: Epidemiology, Volume 13, Pages S223. |
| Authors: Shendell, DG, Lee, S-M, Apte, MG, DiBartolomeo, DB, Sullivan, DP, Liff, SM, Fisk, WJ, Rainer, LI | Type: Journal Article |
| Abstract: Anecdotal evidence suggests heating, ventilation, and air conditioning (HVAC) systems in modular classrooms are not operated effectively. Teachers are usually in charge of thermal control. Due to inadequate training in HVAC system operation and indoor environmental quality (IEQ) issues, and the relatively loud noise produced by the HVAC system while meeting cooling or heating demands, teachers may avoid using mechanical ventilation. Adequate ventilation is an important link between improved IEQ and energy efficiency for schools. Indoor air quality and physical environmental stresses including noise can adversely impact the health of young children and teachers. During the school year these occupants spend the majority of the 7-8 hour school day inside their classrooms. Therefore, classroom noise levels can be assumed to drive personal school day exposures. As part of a field project of IEQ and energy efficiency, we investigated noise levels in four new relocatable classrooms (RCs). The RCs were equipped with both standard and advanced HVAC systems, alternately operated in a case-crossover study design. Classroom noise data, measured as A-weighted decibels (dB(A)), were collected continuously for the 2001-02 school year with sound level meters (SLM; Extech #407736, Type II, 1.5 dB(A) accuracy, 0.1 dB(A) resolution). A SLM was suspended downward below the ceiling at the center of each 960 ft2 RC from a specially designed mobile located ~7.0 ft above the floor. The microphone placement and orientation complied with ANSI and IEC specifications; weekly calibration was performed. Reflectance off ceiling tiles, walls, and student desks were negligible. Descriptive statistics were calculated for each classroom for six distinct time periods: start of school day to recess; recess to lunch; the unoccupied lunch period; lunch to end of school day; overnight; and, weekend. Data were stratified by HVAC system in operation and summarized for four periods: fall cooling season; fall-to-winter transitional period; winter heating season; and spring. This study suggests HVAC systems and occupants were the dominant sources of noise exposure for the RCs indoor environment. In the cooling season, at one school, school-day time-weighted average (Leq) values, in dB(A), were 60.0 and 61.0; at the other school, the values in September were 52.2 and 55.7, and in October were 54.3 and 56.0. Examining specific early morning and lunch periods when HVAC systems were on but RCs unoccupied, the advanced system contributed less noise (4-8 dB(A)) than the standard system (10-15 dB(A)). Mean observed classroom noise levels for several time periods, as well as school-day and school morning Leq values, exceeded existing school district, state, and international guidelines of 40-50 dB(A). | |
| Report number: LBNL-51583 | Year: 2002 |
| Title: Measuring rates of outdoor airflow into HVAC systems | Published in: |
| Authors: Fisk, W.J., Faulkner, D, Sullivan, D, Delp, W. | Type: Journal Article |
| Abstract: During the last few years, new technologies have been introduced for measuring the flow rates of outside air into HVAC systems. This document describes one particular technology for measuring these airflows, a system and a related protocol developed to evaluate this and similar measurement technologies under conditions without wind, and the results of our evaluations. We conclude that the measurement technology evaluated can provide a reasonably accurate measurement of OA flow rate over a broad range of flow, without significantly increasing airflow resistance. | |
| Report number: LBNL-50612 | Year: 2002 |
| Title: A priority agenda for energy-related indoor environmental quality research | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 2, Pages 984-989. |
| Authors: Fisk, W.J., Brager, G., Brook, M., Burge, H., Cole, J., Cummings, J., Levin, H., Loftness, V., Logee, T., Mendell, M.J., Persily, A., Taylor, S., Zhang, J. | Type: Conference Proceedings |
| Abstract: A multidisciplinary team of IEQ and energy researchers is working together to define a program of priority energy-related IEQ research. This paper describes the methods employed, ten high priority broad research and development (R&D) goals, and 34 high priority R&D project areas linked to these goals. | |
| Report number: LBNL-49581 | Year: 2002 |
| Title: Energy and indoor environmental quality in relocatable classrooms | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 2, Pages 62-69. |
| Authors: Apte, M., Hodgson, A., Shendell, D., Dibartolomeo, D., Hotchi, T., Kumar, S., Lee, S.M., Liff, S., Rainer, L., Schmidt, R., Sullivan, D., Diamond, R., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: Relocatable classrooms (RCs) are commonly utilized by school districts with changing demographics and enrollment sizes. Four energy-efficient RCs were designed and constructed for this study to demonstrate technologies that simultaneously attempt to improve energy efficiency and indoor environmental quality (IEQ). Two were installed at each of two school districts, and energy use and IEQ parameters were monitored during occupancy. Two (one per school) were finished with materials selected for reduced emissions of toxic and odorous volatile organic compounds (VOCs). Each RC had two HVAC systems, alternated weekly, consisting of a standard heat-pump system and an indirect-direct evaporative cooling (IDEC) system with gas-fired hydronic heating. The hypothesized advantages of the IDEC include continuous outside air ventilation at ?7.5 L s-1 per person, ~70% less cooling energy and efficient particle filtration. Measurements include: carbon dioxide, particles, VOCs, temperature, humidity, thermal comfort, noise, meteorology, and energy use. Preliminary IEQ monitoring results are reported. | |
| Report number: | Year: 2001 |
| Title: Linking Energy Efficiency and Indoor Environmental Quality to Provide Thermal Comfort and Reduce Children's Exposure to Volatile Organic Compounds: Demonstration Project in New Relocatable Classrooms at Northern California Public Schools | Published in: Proceedings of the 11th Annual Meeting of the International Society for Exposure Analysis, Charleston, SC, Pages 148. |
| Authors: Shendell, D.G., M.G. Apte, D. DiBartolomeo, W. J. Fisk, A.T. Hodgson, S. Kumar, D.P. Sullivan, L.I. Rainer. | Type: Conference Proceedings |
| Report number: | Year: 2001 |
| Title: Studying the Public School Environment and Classroom Indoor Air Quality: Community-based Exposure Assessments Through Public-Private-Government Partnerships, Examples from CA and TX | Published in: |
| Authors: Shendell, D.G., Apte, M.G., Corsi, R., Jenkins, M.P., Kim, J., Smorodinsky, S., Torres, V., J.M. Waldman | Type: |
| Report number: | Year: 2001 |
| Title: California Demonstration Energy Efficiency-Indoor Environmental Quality Project: Predicted Relocatable Classroom Indoor Air Quality due to Low-Emitting Interior Materials and Enhanced Ventilation | Published in: Proceedings of the 11th Annual Meeting of the International Society of Exposure Analysis, Charleston, SC. |
| Authors: Apte, M.G., Fisk, W.J., Hodgson, A.T., Russell, M., Shendell. D.G. | Type: Conference Proceedings |
| Report number: LBNL-45463 | Year: 2000 |
| Title: Recent Research on Indoor Air Quality: A Compilation in Memory of Joan Daisey | Published in: |
| Authors: IED Staff | Type: Journal Article |
| Report number: LBNL-43835 | Year: 2000 |
| Title: Particle concentrations and sizes with normal and high efficiency filtration in a sealed air-conditioned office building | Published in: Aerosol Science & Technology, Volume 32, Pages 527-544. |
| Authors: Fisk, W.J., Faulkner D., Sullivan, D., Mendell, M.J. | Type: Journal Article |
| Report number: | Year: 1999 |
| Title: Characterization of endotoxin and 3-hydroxy fatty acids in an office building | Published in: Indoor Air, Volume 10, Pages 2-12. |
| Authors: Hines, C.J., Milton, D.K., Larsson, L., Petersen, M.R., Fisk, W.J., Mendell, M.J. | Type: Journal Article |
| Report number: | Year: 1999 |
| Title: Indoor Air Quality, Ventilation and Health Symptoms in Schools: An Analysis of Existing Information | Published in: Proceedings of the Indoor Air '99, Edinburgh, Scotland, Volume 2, Pages 1-6. |
| Authors: Daisey, J. | Type: Conference Proceedings |
| Report number: LBNL-43832 | Year: 1999 |
| Title: A New Carbon Monoxide Occupational Dosimeter: Results from a Worker Exposure Assessment Survey | Published in: Journal of Exposure Analysis and Environmental Epidemiology, Volume 9, Pages 546-559. |
| Authors: Apte, M.G., Hammond, S.K., Gundel, L.A., Cox, D. | Type: Journal Article |
| Report number: LBNL-42099 | Year: 1998 |
| Title: Demonstration and Field Test of air jacket technology | Published in: |
| Authors: Faulkner, D., W.J. Fisk, A.J. Gadgil, D.P. Sullivan | Type: Report |
| Report number: LBNL-41517 | Year: 1998 |
| Title: Survey and Critical Review of the Literature on Indoor Air Quality, Ventilation and Health Symptoms in Schools | Published in: |
| Authors: Daisey, J.M., Angell, W.J. | Type: Report |
| Report number: LBNL-53605 | Year: 2003 |
| Title: Duct Leakage Impacts on VAV System Performance in Large Commercial Buildings | Published in: |
| Authors: Wray, Craig P., Matson, Nance E. | Type: Report |
| Abstract: The purpose of this study is to evaluate the variability of duct leakage impacts on air distribution system performance for typical large commercial buildings in California. Specifically, a hybrid DOE-2/TRNSYS sequential simulation approach was used to model the energy use of a low-pressure terminal-reheat variable-air-volume (VAV) HVAC system with six duct leakage configurations (tight to leaky) in nine prototypical large office buildings (representing three construction eras in three California climates where these types of buildings are common). Combined fan power for the variable-speed-controlled supply and return fans at design conditions was assumed to be 0.8 W/cfm. The VAV system that we simulated had perfectly insulated ducts, and maintained constant static pressure in the ducts upstream of the VAV boxes and a constant supply air temperature at the air-handler. Further evaluations of duct leakage impacts should be carried out in the future after methodologies are developed to deal with duct surface heat transfer effects, to deal with airflows entering VAV boxes from ceiling return plenums (e.g., to model parallel fan-powered VAV boxes), and to deal with static pressure reset and supply air temperature reset strategies. | |
| Report number: LBNL-53410 | Year: 2003 |
| Title: Duct Thermal Performance Models for Large Commercial Buildings | Published in: |
| Authors: Wray, Craig P. | Type: Report |
| Abstract: Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy- saving benefits associated with efficient duct systems in large commercial buildings. | |
| Report number: LBNL-51860 | Year: 2003 |
| Title: Thermal distribution systems in commercial buildings | Published in: |
| Authors: Diamond, R.C., Wray, C.P., Dickerhoff, D.J., Matson, N.E., Wang, D. | Type: Journal Article |
| Abstract: Previous research suggests that HVAC thermal distribution systems in commercial buildings suffer from thermal losses, such as those caused by duct air leakage and poor duct location. Due to a lack of metrics and data showing the potentially large energy savings from reducing these losses, the California building industry has mostly overlooked energy efficiency improvements in this area. The purpose of this project is to obtain the technical knowledge needed to properly measure and understand the energy efficiency of these systems. This project has three specific objectives: to develop metrics and diagnostics for determining system efficiencies, to develop design and retrofit information that the building industry can use to improve these systems, and to determine the energy impacts associated with duct leakage airflows in an existing large commercial building. The primary outcome of this project is the confirmation that duct leakage airflows can significantly impact energy use in large commercial buildings: our measurements indicate that adding 15% duct leakage at operating conditions leads to an increase in fan power of about 25 to 35%. This finding is consistent with impacts of increased duct leakage airflows on fan power that have been predicted by previous simulations. Other project outcomes include the definition of a new metric for distribution system efficiency, the demonstration of a reliable test for determining duct leakage airflows, and the development of new techniques for duct sealing. We expect that the project outcomes will lead to new requirements for commercial thermal distribution system efficiency in future revisions of California's Title 24. | |
| Report number: LBNL-44331 | Year: 2002 |
| Title: Performance of thermal distribution systems in large commercial buildings | Published in: Energy and Buildings, Volume 34, Pages 215-226. |
| Authors: Xu, T.T., Carrie, F.R., Dickerhoff, D.J., Fisk, W.J., McWilliams, J., Wang, D., Modera, M.P. | Type: Journal Article |
| Abstract: This paper presents major findings of a field study on the performance of five thermal distribution systems in four large commercial buildings. The five systems studied are typical single-duct or dual-duct constant air volume (CAV) systems and variable air volume (VAV) systems, each of which serves an office building or a retail building with floor area over 2,000 m2. The air leakage from ducts are reported in terms of effective leakage area (ELA) at 25 Pa reference pressure, the ASHRAE-defined duct leakage class, and air leakage ratios. The specific ELAs ranged from 0.7 to 12.9 cm2 per m2 of duct surface area, and from 0.1 to 7.7 cm2 per square meter of floor area served. The leakage classes ranged from 34 to 757 for the five systems and systems sections tested. The air leakage ratios are estimated to be up to one-third of the fan- supplied airflow in the constant-air-volume systems. The specific ELAs and leakage classes indicate that air leakage in large commercial duct systems varies significantly from system to system, and from system section to system section even within the same thermal distribution system. The duct systems measured are much leakier than the ductwork specified as "unsealed ducts" by ASHRAE. Energy losses from supply ducts by conduction (including convection and radiation) are found to be significant, on the scale similar to the losses induced by air leakage in the duct systems. The energy losses induced by leakage and conduction suggest that there are significant energy-savings potentials from duct-sealing and insulation practice in large commercial buildings. | |
| Report number: LBNL-49470 | Year: 2002 |
| Title: Thermal Distribution System Characteristics and Energy Impacts of Duct Leaks in Light Commercial Buildings | Published in: |
| Authors: Sherman, M.H., Xu, T.T., Abushakra, B., Dickerhoff, D.J., Wang, D.M., Wray, C.P., Modera, M.P. | Type: Journal Article |
| Abstract: No Abstract Available | |
| Report number: LBNL-44220 | Year: 2002 |
| Title: Laboratory and field testing of an aerosol-based duct-sealing technology for large commercial buildings | Published in: ASHRAE Transactions. |
| Authors: Carrie, F. R., Levinson, R., Xu, T. T., Dickerhoff, D. J., Fisk, W. J., McWilliams, J., Modera, M. P., Wang, D. | Type: Journal Article |
| Abstract: Laboratory and field experiments were performed to evaluate the feasibility of sealing leaks in commercial duct systems with an aerosol sealant. The method involves blowing an aerosol through the duct system to seal the leaks from the inside, the principle being that the aerosol particles deposit in the cracks as they try to escape under pressure. It was shown that the seals created with the current sealant material can withstand pressures far in excess of what is found in commercial-building duct systems. We also performed two field experiments in two large-commercial buildings. The ASHRAE leakage classes of the systems were reduced from 653 down to 103, and from 40 down to 3. Methods and devices specifically devised for this application proved to be very efficient at (a) increasing the sealing rate and (b) attaining state-of-the-art duct leakage classes. Additional research is needed to improve the aerosol injection and delivery processes. | |
| Report number: LBNL-42414 | Year: 2001 |
| Title: Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles | Published in: Energy & Buildings, Volume 34, Pages 705-714. |
| Authors: Modera, M.P, Brzozowski, O, Carrie, F.R, Dickerhoff, D.J, Delp, W.W, Fisk, W.J, Levinson, R, Wang, D. | Type: Journal Article |
| Report number: LBNL-48774 | Year: 2001 |
| Title: Experimental investigation of aerosol deposition on slot-and joint-type leaks | Published in: Journal of Aerosol Science, Volume 33, Pages 1447-1462. |
| Authors: Carrie, F.R., Modera, M.P. | Type: Journal Article |
| Report number: LBNL-45080 | Year: 2000 |
| Title: Commercial Thermal Distribution Systems: Final Report for CIEE/CEC | Published in: |
| Authors: Xu, T. | Type: Report |
| Report number: LBNL-45080 | Year: 2000 |
| Title: Performance Diagnostics of Thermal Distribution Systems in Light Commercial Buildings: Final Report for CIEE/CEC | Published in: Proceedings of the ACEEE 2000 Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 3, Pages 383-394. |
| Authors: Xu, T. | Type: Conference Proceedings |
| Report number: LBNL-42499 | Year: 2000 |
| Title: Effects of air infiltration on the effective thermal conductivity of internal fiberglass insulation and on the delivery of thermal capacity via ducts | Published in: |
| Authors: Levinson, R.M., Delp, W.W., Dickerhoff, D.J., Modera, M.P. | Type: Report |
| Report number: LBNL-45447 | Year: 2000 |
| Title: Effects of Airflow Infiltration on the Thermal Performance of Internally-insulated Ducts | Published in: Energy & Buildings, Volume 32, Pages 345-354. |
| Authors: Levinson, R., Delp, W., Dickerhoff, D., Modera, M. | Type: Journal Article |
| Report number: LBNL-42339 | Year: 2000 |
| Title: Duct systems in large commercial buildings: physical characterization, air leakage and heat conduction gains | Published in: Energy & Buildings, Volume 32, Pages 109-119. |
| Authors: Fisk, W.J., Delp, W.W., Diamond, R.C., Dickerhoff, D.J., Levinson, R., Modera, M.P., Nematollahi, M., Wang, D. | Type: Journal Article |
| Report number: LBNL-44221 | Year: 1999 |
| Title: Duct System Performance and Energy Losses in Large Commercial Building | Published in: |
| Authors: Xu, T. | Type: Report |
| Report number: LBNL-41365 | Year: 1999 |
| Title: Efficient thermal energy distribution in commercial buildings -- Final Report | Published in: |
| Authors: Modera, M., Xu, T., Feustel, H.E., Matson, N.E., Huizenga, C., Baumann, F., Arens, E. | Type: Report |
| Report number: LBNL-43188 | Year: 1998 |
| Title: Measuring advances in HVAC distribution system designs | Published in: |
| Authors: Franconi, Ellen | Type: Report |
| Report number: LBNL-41956 | Year: 1998 |
| Title: Measuring Advances in HVAC Distribution System Design | Published in: Proceedings of the 1998 ACEEE Summer Study on Energy and Efficiency in Buildings, Pacific Grove, CA, Volume 3, Pages 153-165. |
| Authors: Franconi, E. | Type: Conference Proceedings |
| Report number: LBNL-39083 | Year: 1998 |
| Title: Exterior Exposed Ductwork: Delivery Effectiveness and Efficiency | Published in: ASHRAE Transactions, Volume 104, Pages 709-721. |
| Authors: Delp, W.W., Matson, N.E., Modera, M.P. | Type: Journal Article |
| Report number: LBNL-40105 | Year: 1997 |
| Title: Commercial Thermal Distribution Systems: Final Report for CIEE | Published in: |
| Authors: Levinson, R., Delp, W., Dickerhoff, D., Fisk, W., Nematollahi, M., Stordahl, I., Torre, C., Wang, D., Diamond, R., Modera, M. | Type: Report |
| Report number: LBNL-40102 | Year: 1997 |
| Title: Field Investigation of Duct System Performance in California-Light Commercial Buildings | Published in: |
| Authors: Delp, W., Matson, N., Tschudy, E., Modera, M., Diamond, R. | Type: Report |
| Report number: LBL-38538 | Year: 1996 |
| Title: Energy effectiveness of duct sealing and insulation in two multifamily buildings | Published in: Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 1, Pages 247-254. |
| Authors: Walker, I., Modera, M., Tuluca, A., Graham, I. | Type: Conference Proceedings |
| Abstract: Energy losses from forced air distribution systems have a significant impact on the energy efficiency of buildings. Little work has been done to quantify these losses in apartment buildings. In this paper we will discuss field measurements made on four forced air heating systems to evaluate the duct system energy losses to unconditioned basements. The apartments were heated by natural gas furnaces located in the basements. The systems had bare sheet metal ductwork exposed to the basement conditions. The pre- retrofit measurements were made on the systems after sealing large easily visible leaks. The post-retrofit measurements were made after wrapping the ducts in foil backed glass fiber insulation and additional leak sealing. Only the sections of duct exposed to the basement were retrofitted because only these sections were accessible. This study examines the potential energy savings for this type of limited retrofit. The energy losses were separated into leakage and conduction terms. Leakage measurements were made using register flowhood techniques. Conduction losses were estimated by measuring temperatures in the plenums and at the registers. Analysis of the measurements has shown typical reduction in leakage flow due to duct sealing of about 40%. The reduction in leakage translated into a reduction in energy consumption of about 10%. | |
| Report number: LBL-36636 | Year: 1995 |
| Title: Development of a Model to Simulate the Performance of Hydronic Radiant Cooling Ceilings | Published in: |
| Authors: Stetiu, C., Feustel, H. E. | Type: Journal Article |
| Report number: LBNL-62508 | Year: 2008 |
| Title: Air Filter Materials, Outdoor Ozone and Building-Related Symptoms in the BASE Study | Published in: Indoor Air, Volume 18, Pages 144-155. |
| Authors: Buchanan, I.S., Mendell, M. J., Mirer, A., Apte, M.G. | Type: Journal Article |
| Abstract: Used ventilation air filters have been shown to reduce indoor environmental quality and worker performance and increase symptoms, with effects stronger after reaction of filters with ozone. We analyzed data from the U.S. EPA Building Assessment Survey and Evaluation (BASE) study to determine if ozone and specific filter media have interactive effects on building-related symptoms (BRS). We analyzed a subset of 34 buildings from the BASE study of 100 U.S. office buildings to determine the separate and joint associations of filter medium (polyester/synthetic (PS) or fiberglass (FG)) and outdoor ozone concentration (above/below the median, 67.6 mg/m3) with BRS. Using logistic regression models and general estimating equations, we estimated odds ratios (ORs) and 95% confidence intervals for the association of filter medium, ozone, and filter medium*ozone with BRS. Relative to FG+low ozone, PS alone or high ozone alone each were significantly (p<0.05) associated only with fatigue/difficulty concentrating (ORs = 1.93, 1.54, respectively). However, joint exposure to both PS+high ozone, relative to FG+low ozone, had significant associations with lower and upper respiratory, cough, eye, fatigue, and headache BRS (ORs ranged from 2.26-5.90). Joint ORs for PS+high ozone for lower and upper respiratory and headache BRS were much greater than multiplicative, with interaction p-values < 0.10. Attributable risk proportion (ARP) estimates indicate that removing both risk factors might, given certain assumptions, reduce BRS by 26%-62%. These findings suggest possible adverse health consequences from chemical interactions between outdoor ozone and PS filters in buildings. Results need confirmation before recommending changes in building operation. However, if additional research confirms causality, ARP estimates indicate that appropriate filter selection may substantially reduce BRS in buildings, especially in high ozone areas. | |
| Report number: LBNL-59631 JArt | Year: 2007 |
| Title: Performance of ultra-violet Photocatalytic Oxidation for Indoor Air Cleaning Applications | Published in: Indoor Air, Volume 17, Pages 305-316. |
| Authors: Hodgson, A., Destaillats, H., Sullivan, D, Fisk, W.J. | Type: Journal Article |
| Abstract: Acceptable indoor air quality in office buildings may be achieved with less energy by combining effective air cleaning systems for volatile organic compounds (VOCs) with particle filtration than by relying solely on ventilation. For such applications, ultraviolet photocatalytic oxidation (UVPCO) systems are being developed for VOC removal. An experimental evaluation of a UVPCO system with tungsten oxide modified titanium dioxide as the photocatalyst is reported. The evaluation is unique in that it employed complex VOC mixtures. One of the mixtures contained 27 VOCs commonly found in office buildings, and the other comprised 10 VOCs emitted by cleaning products, in both cases at realistically low concentrations. VOC conversion efficiencies varied over a broad range, usually exceeded 20%, and were as high as ~80%. Conversion efficiency generally diminished with increased air flow rate, and followed the approximate order: alcohols and glycol ethers > aldehydes, ketones, and terpene hydrocarbons > aromatic and alkane hydrocarbons > halogenated aliphatic hydrocarbons. Conversion efficiencies were observed to correlate with the Henry's law constant of the studied VOCs more closely than with other physicochemical parameters. An empirical model based on the Henry's law constant and the gas-phase reaction rate with hydroxyl radical facilitated an estimate of pseudo-first order photocatalytic reaction rates for the studied VOCs. Significant amounts of formaldehyde and acetaldehyde were produced due to incomplete mineralization suggesting that safe deployment of UVPCO in buildings likely will require mitigation methods for these undesirable pollutants. | |
| Report number: LBNL-63420 | Year: 2007 |
| Title: Demand Controlled Filtration in an Industrial Cleanroom | Published in: |
| Authors: Faulkner, D., DiBartolomeo, D., Wang, D. | Type: Report |
| Report number: LBNL-60682 | Year: 2006 |
| Title: Indoor-outdoor air leakage of apartments and commercial buildings. | Published in: |
| Authors: Price, P. N., Shehabi, A., Chan, W.R., Gadgil, A. | Type: Report |
| Report number: LBNL-59631 | Year: 2006 |
| Title: Evaluation of Ultra-Violet Photocatalytic Oxidation for Indoor Air Applications | Published in: Proceedings of Healthy Buildings 2006 Conference, Volume 2, Pages 243-248. |
| Authors: Hodgson, A., Sullivan, D, Fisk, W.J. | Type: Conference Proceedings |
| Abstract: This paper summarizes three analyses of data on building-related environmental factors and occupant symptoms collected from 100 representative large U.S. office buildings. Using multivariate logistic regression models, we found increased occupant symptoms associated with a number of building-related factors, including lower ventilation rates even at the current guideline levels, lack of scheduled cleaning for air-conditioning drain pans and cooling coils, poor condition of cooling coils, poorly maintained humidification systems, and lower outdoor air intake height. Some expected relationships were not found, and several findings were opposite of expected. Although requiring replication, these findings suggest preventive actions to reduce occupant symptoms in office buildings. | |
| Report number: LBNL-60254 | Year: 2006 |
| Title: Photocatalytic Reactor System with Tungsten Oxide-Modified Titanium Dioxide for Indoor Air Applications | Published in: The 11th International Conference on Ti02 Photocatalysis: Fundamentals and Applications (Ti02-11). |
| Authors: Hodgson, A., Destaillats, H., Sullivan, D, Fisk, W.J. | Type: Conference Proceedings |
| Report number: LBNL-61862 | Year: 2006 |
| Title: Accuracy of CO2 Sensors in Commercial Buildings: A Pilot Study. | Published in: |
| Authors: Fisk, W.J., Faulkner, D., Sullivan, D.P. | Type: Report |
| Abstract: Carbon dioxide (CO2) sensors are often deployed in commercial buildings to obtain CO2 data that are used to automatically modulate rates of outdoor air supply. The goal is to keep ventilation rates at or above code requirements, but to also to save energy by avoiding over-ventilation relative to code requirements. However, there have been many anecdotal reports of poor CO2 sensor performance in actual commercial building applications. This study evaluated the accuracy of 44 CO2 sensors located in nine commercial buildings to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. CO2 measurement errors varied widely and were sometimes hundreds of parts per million. Despite its small size, this study provides a strong indication that the accuracy of CO2 sensors used in commercial buildings is frequently less than is needed to measure peak indoor-outdoor CO2 concentration differences with less than a 20% error. Thus, we conclude that there is a need for more accurate CO2 sensors and/or better sensor maintenance or calibration procedures. | |
| Report number: LBNL-58753 | Year: 2006 |
| Title: Measuring Outdoor Airflow into HVAC Systems | Published in: ASHRAE Journal, Volume 48, Pages 50-57. |
| Authors: Fisk, W.J., Faulkner, D, Sullivan, D | Type: Journal Article |
| Report number: LBNL-60162 | Year: 2006 |
| Title: Sorbent-based gas phase air cleaning for VOCs in Commercial Buildings. | Published in: |
| Authors: Fisk, W.J. | Type: Report |
| Report number: LBNL-59663 | Year: 2006 |
| Title: Air Filter Materials and Building Related Symptoms in the BASE Study | Published in: Healthy Buildings Conference 2006, Volume 4, Pages 455-460. |
| Authors: Buchanan, I.S., Apte, M.G. | Type: Conference Proceedings |
| Abstract: Mechanical ventilation of buildings is a risk factor for building related symptoms (BRS). This analysis examines air filters within mechanical ventilation systems to determine their effect on BRS. We hypothesize that certain ventilation filter materials will contribute more than others to the burden of building related headaches, mucous membrane (MM) and lower respiratory (LR) BRS within a building. This hypothesis was tested using the USEPA Building Assessment, Survey and Evaluation (BASE) study. Logistic regression models constructed to control for personal, workplace, and environmental factors reveled statistically significant (p<0.05) associations between the increased prevalence of building related headaches, certain MM and LR BRS and polyester or synthetic containing air filters in a ventilation system, relative to fiberglass or cotton air filters. | |
| Report number: LBNL-60170 | Year: 2006 |
| Title: A Review of Demand Control Ventilation | Published in: Proceedings of Healthy Buildings 2006, Volume IV. |
| Authors: Apte, M G. | Type: Conference Proceedings |
| Abstract: This paper provides background and update on demand control ventilation (DCV) technology for commercial buildings, its penetration and acceptance in the market, and to identify what evidence there is that such systems are benefiting current building stakeholders in terms of energy savings, improved indoor environmental quality, and reduced complaints. The paper also provides a basis for a study design to assess the effectiveness of existing DCV systems operating under real conditions. | |
| Report number: LBNL-56381 | Year: 2005 |
| Title: Outdoor Air Ventilation and Work-Related Symptoms in U.S. Office Buildings - Results from the Base Study | Published in: |
| Authors: Mendell, M.J. , Lei, Q., Apte, M.G. , Fisk, W.J. | Type: Report |
| Abstract: Insufficient information has been available on measured ventilation rates and symptoms in office workers. Using U.S. EPA data from 100 large U.S. office buildings, we assessed relationships in multivariate models between ventilation/person and lower respiratory and mucous membrane symptoms. Three preliminary ventilation estimates were used, based on CO2 ratio in airstreams, peak indoor CO2 concentrations, and volumetric estimates of flow rates. Ventilation rates (VRs) from 6-17 cfm/person above the current 20 cfm/person guideline for offices were associated generally with reduced symptom prevalence, but further benefits were not evident from higher VRs. For all ventilation estimates, higher occupant density was independently associated with more symptoms. Findings suggest that VRs somewhat above current guidelines would reduce symptoms in office workers, and that occupant density may play an unrecognized role in ventilation requirements. Different findings for the various ventilation estimates were surprising. Clarification of these relationships, and validation of VR measurement methods are necessary. | |
| Report number: LBNL-57102 | Year: 2005 |
| Title: Estimated Ventilation Rates and Work-Related Symptoms in U.S. Office Buildings - The Base Study | Published in: 10th International Conference on Indoor Air Quality and Climate, Volume 5(6), Pages 3758-3762. |
| Authors: Mendell, M.J., Lei, Q., Apte, M G., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: Insufficient information has been available on measured ventilation rates and symptoms in office workers. Using U.S. EPA data from 100 large U.S. office buildings, we assessed relationships in multivariate models between ventilation/person and lower respiratory and mucous membrane symptoms. Three preliminary ventilation estimates were used, based on CO2 ratio in airstreams, peak indoor CO2 concentrations, and volumetric estimates of flow rates. Ventilation rates (VRs) from 6-17 cfm/person above the current 20 cfm/person guideline for offices were associated generally with reduced symptom prevalence, but further benefits were not evident from higher VRs. For all ventilation estimates, higher occupant density was independently associated with more symptoms. Findings suggest that VRs somewhat above current guidelines would reduce symptoms in office workers, and that occupant density may play an unrecognized role in ventilation requirements. Different findings for the various ventilation estimates were surprising. Clarification of these relationships, and validation of VR measurement methods are necessary. | |
| Report number: LBNL-59074 | Year: 2005 |
| Title: Parametric Evaluation of an Innovative Ultra-Violet Photocatalytic Oxidation (UVPCO) Air Cleaning Technology for Indoor Applications | Published in: |
| Authors: Hodgson, A., Sullivan, D, Fisk, W.J. | Type: Report |
| Abstract: An innovative Ultra-Violet Photocatalytic Oxidation (UVPCO) air cleaning technology employing a semitransparent catalyst coated on a semitransparent polymer substrate was evaluated to determine its effectiveness for treating mixtures of volatile organic compounds (VOCs) representative of indoor environments at low, indoor-relevant concentration levels. The experimental UVPCO contained four 30 by 30-cm honeycomb monoliths irradiated with nine UVA lamps arranged in three banks. A parametric evaluation of the effects of monolith thickness, air flow rate through the device, UV power, and reactant concentrations in inlet air was conducted for the purpose of suggesting design improvements. The UVPCO was challenged with three mixtures of VOCs. A synthetic office mixture contained 27 VOCs commonly measured in office buildings. A building product mixture was created by combining sources including painted wallboard, composite wood products, carpet systems, and vinyl flooring. The third mixture contained formaldehyde and acetaldehyde. Steady state concentrations were produced in a classroom laboratory or a 20-m3 chamber. Air was drawn through the UVPCO, and single-pass conversion efficiencies were measured from replicate samples collected upstream and downstream of the reactor. Thirteen experiments were conducted in total. In this UVPCO employing a semitransparent monolith design, an increase in monolith thickness is expected to result in general increases in both reaction efficiencies and absolute reaction rates for VOCs oxidized by photocatalysis. The thickness of individual monolith panels was varied between 1.2 and 5 cm (5 to 20 cm total thickness) in experiments with the office mixture. VOC reaction efficiencies and rates increased with monolith thickness. However, the analysis of the relationship was confounded by high reaction efficiencies in all configurations for a number of compounds. These reaction efficiencies approached or exceeded 90% for alcohols, glycol ethers, and other individual compounds including d-limonene, 1,2,4-trimethylbenzene, and decamethylcyclopentasiloxane. This result implies a reaction efficiency of about 30% per irradiated monolith face, which is in agreement with the maximum efficiency for the system predicted with a simulation model. In these and other experiments, the performance of the system for highly reactive VOCs appeared to be limited by mass transport of reactants to the catalyst surface rather than by photocatalytic activity. Increasing the air flow rate through the UVPCO device decreases the residence time of the air in the monoliths and improves mass transfer to the catalyst surface. The effect of gas velocity was examined in four pairs of experiments in which the air flow rate was varied from approximately 175 m3/h to either 300 or 600 m3/h. Increased gas velocity caused a decrease in reaction efficiency for nearly all reactive VOCs. For all of the more reactive VOCs, the decrease in performance was less, and often substantially less, than predicted based solely on residence time, again likely due to mass transfer limitations at the low flow rate. The results demonstrate that the UVPCO is capable of achieving high conversion efficiencies for reactive VOCs at air flow rates above the base experimental rate of 175 m3/h. The effect of UV power was examined in a series of experiments with the building product mixture in which the number of lamps was varied between nine and three. For the most reactive VOCs in the mixture, the effects of UV power were surprisingly small. Thus, even with only one lamp in each section, there appears to be sufficient photocatalytic activity to decompose most of the mass of reactive VOCs that reach the catalyst surface. For some less reactive VOCs, the trend of decreasing efficiency with decreasing UV intensity was in general agreement with simulation model predictions. The UVPCO device easily decomposed formaldehyde. At an air flow rate near 300 m3/h, the reaction efficiency was about 60%. There was no apparent effect on conversion of formaldehyde concentration in the range of 24 to 88 ppb. However, the reaction efficiency was about 40 - 50% higher than predicted based on unreported experiments conducted at 1 ppm. Formaldehyde, acetaldehyde, and acetone were produced as reaction products in these experiments. Overall, about 22% of the carbon introduced into the device was converted to these products instead of completely oxidizing to carbon dioxide. Acetone, a compound with relatively low toxicity, comprised about 60% of the products formed. In experiments with the office VOC mixture there was substantial formation of acetaldehyde and low net formation of formaldehyde. The mixture contained ethanol, a likely reactant leading to acetaldehyde formation. In experiments with the building product mixture, both formaldehyde and acetaldehyde were formed. The design of a UVPCO device for use in occupied buildings needs to minimize the formation of these two unwanted byproducts as they are considered to be carcinogens and have relatively low exposure guidelines for noncancer effects. | |
| Report number: LBNL-58936 | Year: 2005 |
| Title: Evaluation of Ultra-Violet Photocatalytic Oxidation (UVPCO) for Indoor Air Applications: Conversion of Volatile Organic | Published in: |
| Authors: Hodgson, A., Sullivan, D, Fisk, B. | Type: Report |
| Abstract: Efficient removal of indoor generated airborne particles and volatile organic compounds (VOCs) in office buildings and other large buildings may allow for a reduction in outdoor air supply rates with concomitant energy savings while still maintaining acceptable indoor air quality in these buildings. Ultra-Violet Photocatalytic Oxidation (UVPCO) air cleaners have the potential to achieve the necessary reductions in indoor VOC concentrations at relatively low cost. In this study, laboratory experiments were conducted with a scaled, prototype UVPCO device designed for use in a duct system. The experimental UVPCO contained two 30 by 30-cm honeycomb monoliths coated with titanium dioxide and 3% by weight tungsten oxide. The monoliths were irradiated with 12 UVC lamps arranged in four banks. The UVPCO was challenged with four mixtures of VOCs typical of mixtures encountered in indoor air. A synthetic office mixture contained 27 VOCs commonly measured in office buildings. A cleaning product mixture contained three cleaning products with high market shares. A building product mixture was created by combining sources including painted wallboard, composite wood products, carpet systems, and vinyl flooring. A fourth mixture contained formaldehyde and acetaldehyde. Steady-state concentrations were produced in a classroom laboratory or a 20-m3 environmental chamber. Air was drawn through the UVPCO, and single pass conversion efficiencies were measured from replicate air samples collected upstream and downstream of the reactor section. Concentrations of the mixtures were manipulated, with concentrations of individual VOCs mostly maintained below 10 ppb. Device flow rates were varied between 165 and 580 m3/h. Production of formaldehyde, acetaldehyde, acetone, formic acid, and acetic acid as reaction products was investigated. Conversion efficiency data were generated for 48 individual VOCs or groups of closely related compounds. Alcohols and glycol ethers were the most reactive chemical classes with conversion efficiencies often near or above 70% at the low flow rate and near 40% at the high flow rate. Ketones and terpene hydrocarbons were somewhat less reactive. The relative VOC conversion rates are generally favorable for treatment of indoor air since many contemporary products used in buildings employ oxygenated solvents. A commercial UVPCO device likely would be installed in the supply air stream of a building and operated to treat both outdoor and recirculated air. Assuming a recirculation rate comparable to three times the normal outdoor air supply rate, simple mass-balance modeling suggests that a device with similar characteristics to the study unit has sufficient conversion efficiencies for most VOCs to compensate for a 50% reduction in outdoor air supply without substantially impacting indoor VOC concentrations. Formaldehyde, acetaldehyde, acetone, formic acid, and acetic acid were produced in these experiments as reaction byproducts. No other significant byproducts were observed. A coupled steady-state mass balance model is presented and applied to VOC data from a study of a single office building. For the operating assumptions described above, the model estimated a three-fold increase in indoor formaldehyde and acetaldehyde concentrations. The outcome of this limited assessment suggests that evaluation of the potential effects of the operation of a UVPCO device on indoor concentrations of these contaminants is warranted. Other suggested studies include determining VOC conversion efficiencies in actual buildings and evaluating changes in VOC conversion efficiency as monoliths age with long-term operation. | |
| Report number: LBNL-58856 | Year: 2005 |
| Title: Real-Time Measurement of Rates of Outdoor Airflow into HVAC Systems: A Field Study of Three Technologies | Published in: |
| Authors: Fisk, W.J., Sullivan, D, Faulkner, D | Type: Report |
| Abstract: Technologies for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems are now available commercially. Our prior papers reported on laboratory-based evaluations of these measurement technologies and this document describes the methods and results of a field study of the accuracy of three of these technologies. From the field study data, we determined that neither wind speed nor wind direction have an important adverse impact on measurement accuracy. The field study confirmed that these three measurement technologies can provide reasonably accurate measurements of outdoor air intake rates in field settings, if the pressure signals are measured with high accuracy. Some of the pressure transducers marketed for use with commercial HVAC systems were determined to be sufficiently accurate for this application. Given the significant impact of OA flow rates on both energy use and occupant health, more widespread use of technologies that provide for real time measurements of OA flow rates seems warranted. | |
| Report number: LBNL-54475 | Year: 2005 |
| Title: Economic benefits of an economizer system: energy savings and reduced sick leave | Published in: ASHRAE Transactions, Volume 111, Pages 673-679. |
| Authors: Fisk, W.J., Seppanen, O., Faulkner, D., Huang, J. | Type: Journal Article |
| Abstract: Abstract: This study estimated the health, energy, and economic benefits of an economizer ventilation control system that increases outside air supply during mild weather to save energy. A model of the influence of ventilation rate on airborne transmission of respiratory illnesses was used to extend the limited data relating ventilation rate with illness and sick leave. An energy simulation model calculated ventilation rates and energy use versus time for an office building in Washington, D.C. with fixed minimum outdoor air supply rates, with and without an economiser. Sick leave rates were estimated with the disease transmission model. In the modelled 72-person office building, our analyses indicate that the economizer reduces energy costs by approximately $2000 and, in addition, reduces sick leave. The annual financial benefit of the decrease in sick leave is estimated to be between $6,000 and $16,000. This modelling suggests that economizers are much more cost effective than currently recognized. | |
| Report number: LBNL-62102 | Year: 2005 |
| Title: Performance of underfloor air distribution in a field setting | Published in: International Journal of Ventilation, Volume 5, Pages 291-300. |
| Authors: Fisk, W.J., Faulkner, D., Sullivan, D.P., Chao, C., Wan, M.P., Zagreus, L., Webster, T. | Type: Journal Article |
| Report number: LBNL-57098 | Year: 2005 |
| Title: Results Of A Field Study Of Underfloor Air Distribution | Published in: Proceedings of The 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume 1(7), Pages 1016 – 1020. |
| Authors: Fisk, W.J., Faulkner, D., Sullivan, D., Chao, C., Wan, M.P., Zagreus, L., Webster, T. | Type: Conference Proceedings |
| Abstract: Underfloor air distribution (UFAD) is a method of supplying conditioned air via floor mounted air supply diffusers. We measured several aspects of the performance of an UFAD system in an office building. The air change effectiveness was very close to unity, which is comparable to that measured in buildings with typical overhead air distribution. The pollutant removal efficiency for carbon dioxide was 13% higher than expected with well-mixed air. The increase in air temperatures with height above the floor was only 1 to 2 oC. This amount of thermal stratification could reduce the sensible energy requirements for cooling of outdoor air by approximately 10%. The occupant's satisfaction with thermal conditions was well above average. Thus, the results of this study provide some evidence of moderate energy and IAQ-related benefits of UFAD; however, the benefits need to be confirmed in other studies. | |
| Report number: LBNL-56604 | Year: 2005 |
| Title: Technologies For Measuring Flow Rates Of Outdoor Air Into Hvac Systems: Some Causes And Suggested Cures For Measurement Errors | Published in: ASHRAE Transactions, Volume 111, Pages 456-463. |
| Authors: Fisk, W.J., Faulkner, D, Sullivan, D | Type: Journal Article |
| Abstract: Although the rate of outdoor air (OA) ventilation has a substantial influence on building energy consumption and occupant health, the available data indicate the outdoor air ventilation rates are poorly controlled in many buildings. Technologies being marketed for real time measurement of the flow rates of outdoor air into HVAC systems should enable better control of OA ventilation. In laboratory research we have studied the performance of these technologies. Sources of measurement errors identified during conduct of this research include: low air speeds; high spatial variability in air speed and direction; large eddies downstream of outdoor air intake louvers; and backwards airflow through a portion of outdoor air dampers. Several suggestions for overcoming these sources of errors were developed including: design and control of the outdoor air intake system to avoid low, hard-to measure, air speeds; use of highly sensitive pressure and velocity sensors; measuring air speeds between blades of louvers, rather than downstream of louvers; smoothing out the airflow between the outdoor air louver and damper through proper louver selection and insertion of components to straighten air flow; and maintaining a pressure drop across the outdoor air damper that exceeds approximately 0.04 IWG (10 Pa). | |
| Report number: LBNL-56603 | Year: 2005 |
| Title: An Evaluation Of Three Commercially Available Technologies For Real-Time Measurement Of Rates Of Outdoor Airflow Into Hvac Systems | Published in: ASHRAE Transactions, Volume 111, Pages 443-455. |
| Authors: Fisk, W.J., Faulkner, D, Sullivan, D | Type: Journal Article |
| Abstract: During the last few years, new technologies have been introduced for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems; however, an evaluation of these measurement technologies has not previously been published. This document describes a test system and protocols developed for a controlled evaluation of these measurement technologies. The results of tests of three commercially available measurement technologies are also summarized. The test system and protocol were judged practical and very useful. The three commercially available measurement technologies should provide reasonably, e.g., 20%, accurate measurements of OA flow rates as long as air velocities are maintained high enough to produce accurately measurable pressure signals. In HVAC systems with economizer controls, to maintain the required air velocities the OA intake will need to be divided into two sections in parallel, each with a separate OA damper. All of the measurement devices had pressure drops that are likely to be judged acceptable. The influence of wind on the accuracy of these measurement technologies still needs to be evaluated. | |
| Report number: LBNL-56257 | Year: 2005 |
| Title: Performance of underfloor air distribution: Results of a field study | Published in: |
| Authors: Fisk, W.J., Faulkner, D, Sullivan, D | Type: Report |
| Abstract: Underfloor air distribution (UFAD) is a new method of supplying heated or cooled air throughout a building. Reported advantages of UFAD include easy relocation of air supply diffusers, energy savings, and improved indoor air quality (IAQ). We measured several aspects of the performance of an UFAD system installed in a medium-size office building. The measured air change effectiveness was very close to unity, which is comparable to that measured in buildings with typical overhead air distribution. The pollutant removal efficiency for carbon dioxide was 13% higher than expected in a space with well-mixed air, suggesting a 13% reduction in exposures to occupant generated pollutants. The increase in indoor air temperatures with height above the floor was only 1 to 2 oC (2-4 oF). This amount of thermal stratification could reduce the sensible energy requirements for cooling of outdoor air by approximately 10%. The occupant's level of satisfaction with thermal conditions was well above average and this high satisfaction rating could possibly be due, in all or part, to the use of a UFAD system. The results of this study provide some evidence of moderate energy and IAQ-related benefits of UFAD. Before general conclusions are drawn, the benefits need to be confirmed in other studies. | |
| Report number: LBNL-57277 | Year: 2005 |
| Title: Improving Indoor Environmental Quality and Energy Performance of Modular Classroom HVAC Systems | Published in: Proceedings of Sustainable Buildings 2005 Conference, Pages 1432-1437. |
| Authors: Apte, M G., Spears, M., Lai, C.M., Shendel, D.G. | Type: Conference Proceedings |
| Abstract: The factory-built relocatable classroom (RC) is a dominant force in the school facility construction industry in the United States (U.S.) and elsewhere. It is estimated that there are approximately 650,000 RCs currently occupied in the U.S., housing about 16 million students. RCs receive public attention due to complaints about poor indoor environmental quality (IEQ). Both measured data and anecdotal evidence in California have suggested excessive acoustical noise from heating, ventilation, and air conditioning (HVAC) equipment as a central factor leading to degraded IEQ. In the U.S., RCs are typically equipped with unitary exterior wall-mount HVAC systems, and interior acoustical noise due to structural and airborne transmission can reach levels of about 58dB(A) with compressor cycling, under unoccupied conditions. Due to these noise levels teachers often simply choose to turn off the HVAC, leading to inadequate ventilation, as well as poor thermal conditioning, and thus to poor indoor air quality. Elevated levels of carbon dioxide and volatile organic compounds including formaldehyde are common. We discuss the acoustic component of our efforts to develop and test energy efficient HVAC systems that address the ventilation, controls, and acoustic requirements necessary to ensure high quality indoor environments in RCs. | |
| Report number: LBNL-58824 | Year: 2005 |
| Title: Improving Ventilation and Saving Energy: Relocatable Classroom Field Study Interim Report | Published in: |
| Authors: Apte, M G., Faulkner, D, Hodgson, A., Hotchi, T., Spears, M., Sullivan, D, Wang, D. | Type: Report |
| Abstract: The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many classrooms are under-ventilated, and public concerns about indoor environmental quality in classrooms. This report presents an interim status update and preliminary findings from energy and indoor environmental quality (IEQ) measurements in sixteen relocatable classrooms in California. The field study includes measurements of HVAC energy use, ventilation rates, and IEQ conditions. Ten of the classrooms were equipped with a new HVAC technology and six control classrooms were equipped with a standard HVAC system. Energy use and many IEQ parameters have been monitored continuously, while unoccupied acoustic measurements were measured in one of four planned seasonal measurement campaigns. Continuously monitored data are remotely accessed via a LonWorks® network and stored in a relational database at LBNL. Preliminary results are presented here. | |
| Report number: LBNL-57172 | Year: 2005 |
| Title: Improving Relocatable Classroom HVAC For Improved IEQ And Energy Efficiency | Published in: Indoor Air 2005 Conference - The 10th International Conference on Indoor Air Quality and Climate, Volume 1(7), Pages 1121-1125. |
| Authors: Apte, M G., Faulkner, D, Fisk, W.J., Hodgson, A.T., Hotchi, T., Lai, C.M., Spears, M., Sullivan, D.P., Wang, D. | Type: Conference Proceedings |
| Abstract: Relocatable classrooms (RCs) in California (CA) alone house about 2 million students in more than 80,000 structures. These buildings are typically under-ventilated, often due to low HVAC utilization because of excessive HVAC acoustic noise, and because when automatically operated they only ventilate during thermal conditioning. It can be predicted that such conditions affect the quality education and student health. These systems are also energy inefficient and peak-load demanding. With a manufacturer of wall-mounted HVAC systems, we are developing a new system addressing these problems. Design goals include a =30% increase the seasonal energy efficiency ratio (SEER) over the current SEER 10 system, noise reduction =45 dB(A), continuous ventilation meeting CA State code requirements (e.g. ASHRAE 62.1 ventilation standard of 7 l s-1 per occupant and a pre-occupancy air purge). The prototype was operated in an RC test-bed to characterize its performance from the standpoint of ventilation, and thermal control, acoustical noise, and energy consumption. Ten of the new HVAC systems are also being monitored for one year in matched pairs with the current standard HVAC systems after being installed in identical occupied RCs in four schools in Northern and Southern CA. Continuous measurements include indoor and outdoor carbon dioxide, temperature, relative humidity, and HVAC power consumption. Additionally, acoustical noise levels; thermal comfort; and concentrations of volatile organic compounds, formaldehyde and acetaldehyde, and ozone will be measured on a regular schedule throughout the study year. Daily classroom occupancy rates will be collected from the class records. The potential IEQ and energy savings benefits of the system will be presented from preliminary data collected in the field. | |
| Report number: LBNL-58577 | Year: 2005 |
| Title: Improving Ventilation and Saving Energy: Laboratory Study in a Modular Classroom Test Bed | Published in: |
| Authors: Apte, M G., Buchanan, C.R., Faulkner, D, Fisk, W.J., Lai, C.M., Spears, M., Sullivan, D | Type: Report |
| Abstract: The primary goals of this research effort were to develop, evaluate, and demonstrate a practical HVAC system for classrooms that consistently provides classrooms with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research was motivated by several factors, including the public benefits of energy efficiency, evidence that many classrooms are under-ventilated, and public concerns about indoor environmental quality in classrooms. This project involved the installation and verification of the performance of an Improved Heat Pump Air Conditioning (IHPAC) system, and its comparison, a standard HVAC system having an efficiency of 10 SEER. The project included the verification of the physical characteristics suitable for direct replacement of existing 10 SEER systems, quantitative demonstration of improved energy efficiency, reduced acoustic noise levels, quantitative demonstration of improved ventilation control, and verification that the system would meet temperature control demands necessary for the thermal comfort of the occupants. Results showed that the IHPAC met these goals. The IHPAC was found to be a direct bolt-on replacement for the 10 SEER system. Calculated energy efficiency improvements based on many days of classroom cooling or heating showed that the IHPAC system is about 44% more efficient during cooling and 38% more efficient during heating than the 10 SEER system. Noise reduction was dramatic, with measured A-weighed sound level for fan only operation conditions of 34.3 dB(A), a reduction of 19 dB(A) compared to the 10 SEER system. Similarly, the IHPAC stage-1 and stage-2 compressor plus fan sound levels were 40.8 dB(A) and 42.7 dB(A), reductions of 14 and 13 dB(A), respectively. Thus, the IHPAC is 20 to 35 times quieter than the 10 SEER systems depending upon the operation mode. The IHPAC system met the ventilation requirements and was able to provide consistent outside air supply throughout the study. Indoor CO2 levels with simulated occupancy were maintained below 1000 ppm. Finally temperature settings were met and controlled accurately. The goals of the laboratory testing phase were met and this system is ready for further study in a field test of occupied classrooms. | |
| Report number: LBNL-56397 | Year: 2004 |
| Title: An evaluation of technologies for real-time measurement of rates of outdoor airflow into HVAC systems | Published in: |
| Authors: Fisk, W.J., Faulkner, D, Sullivan, D | Type: Report |
| Abstract: During the last few years, new technologies have been introduced for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems; however, an evaluation of these measurement technologies has not previously been published. This document describes a test system and protocols developed for a controlled evaluation of these measurement technologies. The results of tests of four commercially available measurement technologies and one prototype based on a new design are also summarized. The test system and protocol were judged practical and very useful. The series of tests identified three commercially available measurement technologies that should provide reasonably accurate measurements of OA flow rates as long as air velocities are maintained high enough to produce accurately measurable pressure signals. In HVAC systems with economizer controls, to maintain the required air velocities the OA intake will need to be divided into two sections in parallel, each with a separate OA damper. The errors in OA flow rates measured with the fourth commercially available measurement technology were 20% to 30% with horizontal probes but much larger with vertical probes. The new prototype measurement technology was the only one that appears suitable for measuring OA flow rates over their full range from 20% OA to 100% OA without using two separate OA dampers. All of the measurement devices had pressure drops that are likely to be judged acceptable. The influence of wind on the accuracy of these measurement technologies still needs to be evaluated. | |
| Report number: LBNL-53798 | Year: 2004 |
| Title: Ventilation Efficiencies And Thermal Comfort Results Of A Desk-Edge-Mounted Task Ventilation System | Published in: Indoor Air (Supplement 8), Volume 14, Pages 92-97. |
| Authors: Faulkner, D., Fisk, W.J., Sullivan, D.P., Lee, S.M. | Type: Journal Article |
| Abstract: In chamber experiments, we investigated the ventilation effectiveness and thermal comfort of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin or a human volunteer seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15o to 45o from horizontal), and the supply flow rate of (3.5 to 6.5 L s-1). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air in the breathing zone) in experiments with the mannequin ranged from 1.4 to 2.7 (median, 1.8), whereas with human subjects the air change effectiveness ranged from 1.3 to 2.3 (median, 1.6). The majority of the air change effectiveness values with the human subjects were less than values with the mannequin at comparable tests. Similarly, the tests run with supply air temperature equal to the room air temperature had lower air change effectiveness values than comparable tests with the supply air temperature lower (~5 o C) than the room air temperature. The change effectiveness values are higher than typically reported for commercially available task ventilation or displacement ventilation systems. Based on surveys completed by the subjects, operation of the task ventilation system did not cause thermal discomfort. | |
| Report number: LBNL-54859 | Year: 2004 |
| Title: Designing Building Systems to Save Energy and Improve Indoor Environments: A Practical Demonstration | Published in: 2004 ACEEE Summer Study on Energy Efficiency in Buildings, Volume 3, Pages 13-27. |
| Authors: Apte, M G., Hodgson, A.T, Shendel, D.G., Rainer, L.I., Hoeschele, M.A. | Type: Conference Proceedings |
| Abstract: Building design concepts that focus on energy efficiency may conflict with those intended to provide excellent indoor environmental quality (IEQ). Careful selection of a heating, ventilating, and air-conditioning (HVAC) system, and low-emission interior finish materials, can result in winwin designs that minimize tradeoffs between energy and IEQ. We demonstrated energy and IEQ benefits in four new relocatable classrooms (RCs) monitored in two climate regions of California for one year. We used a case-crossover experimental design to compare energy and IEQ characteristics of a hybrid HVAC system that provides continuous ventilation (indirect-direct evaporative cooler with high-efficiency hydronic gas heat) to a standard heat pump system. Additionally, we explored the IEQ benefits of measurement-based selection of interior finish materials with low emissions of health-relevant volatile organic compounds (VOCs) including formaldehyde. Monitored data were used to calibrate DOE-2 models that simulated California-wide energy saving potential of RCs employing energy efficient building components including the hybrid HVAC system. IEQ monitoring results from our field investigation indicated that VOC concentration reductions, typically 50% or more, were achieved through improved ventilation while simultaneously average cooling and heating energy costs were reduced by 50% and 30%, respectively. Incremental annual California-wide energy impacts from installation of hybrid HVAC systems in 4,000 new RCs were projected to be: 5,975 MWh of electricity savings; 23.8 MW winter and 13.1 MW summer peak electric load reduction; 1,025 MBtu natural gas consumption from switch to gas heating; 50,931 MBtu source energy reduction; and a combined school district annual operating cost reduction of $880,900. | |
| Report number: LBNL-53191 | Year: 2003 |
| Title: Cost benefit analysis of the night-time ventilative cooling in office building | Published in: Proceedings of the Healthy Buildings 2003 Conference, Singapore, Volume 3, Pages 394-399. |
| Authors: Seppänen, O., Fisk, W.J., Faulkner, D. | Type: Conference Proceedings |
| Abstract: The indoor temperature can be controlled with different levels of accuracy depending on the building and its HVAC system. The purpose of this study was to evaluate the potential productivity benefits of improved temperature control, and to apply the information for a cost-benefit analyses of night-time ventilative cooling, which is a very energy efficient method of reducing indoor daytime temperatures. We analyzed the literature relating work performance with temperature, and found a general decrement in work performance when temperatures exceeded those associated with thermal neutrality. These studies included physiological modelling, performance of various tasks in laboratory experiments and measured productivity at work in real buildings. The studies indicate an average 2% decrement in work performance per degree oC temperature rise, when the temperature is above 25 oC. When we use this relationship to evaluate night- time ventilative cooling, the resulting benefit to cost ratio varies from 32 to 120. | |
| Report number: LBNL-52497 | Year: 2003 |
| Title: Effect of Outside Air Ventilation Rate on Volatile Organic Compound Concentrations in a Call Center | Published in: Atmospheric Environment, Volume 37, Pages 5517-5528. |
| Authors: Hodgson, A.T., Faulkner, D., Sullivan, D.P., Dibartolomeo, D.L., Russell, M.L., Fisk, W.J. | Type: Journal Article |
| Abstract: A study of the relationship between outside air ventilation rate and concentrations of volatile organic compounds (VOCs) generated indoors was conducted in a call center office building. The building, with two floors and a floor area of 4,600 m2, was located in the San Francisco Bay Area, CA. Ventilation rates were manipulated with the building's four air handling units (AHUs). VOC concentrations in the AHU returns were measured on seven days during a 13-week period. VOC emission factors were determined for individual zones on days when they were operating at near steady-state conditions. The emission factor data were subjected to principal component (PC) analysis to identify groups of co-varying compounds. Potential sources of the PC vectors were ascribed based on information from the literature supporting the associations. Two vectors with high loadings of compounds including formaldehyde, 2,2,4-trimethyl-1,3- pentanediol monoisobutyrate, decamethylcyclopentasiloxane (d5 siloxane), and isoprene likely identified occupant-related sources. One vector likely represented emissions from building materials. Another vector represented emissions of solvents from cleaning products. The relationships between indoor minus outdoor VOC concentrations and ventilation rate were qualitatively examined for eight VOCs. Of these, acetaldehyde and hexanal, which were likely associated with material sources, and d5 siloxane exhibited general trends of higher concentrations at lower ventilation rates. For other compounds, the operation of the building and variations in pollutant generation and removal rates apparently combined to obscure the inverse relationship between VOC concentrations and ventilation. This result emphasizes the importance of utilizing source control measures, in addition to adequate ventilation, to limit concentrations of VOCs of concern in office buildings. | |
| Report number: LBNL-53834 | Year: 2003 |
| Title: Outdoor airflow into HVAC systems: An evaluation of measurement technologies | Published in: |
| Authors: Fisk, W.J., Faulkner, D., Sullivan, D.P., Delp, W.W. | Type: Report |
| Abstract: During the last few years, new technologies have been introduced for measuring the flow rates of outdoor air (OA) into HVAC systems; however, an evaluation of these measurement technologies has not previously been published. This document describes a test system and protocols developed for controlled evaluation of these measurement technologies. The results of tests of three measurement technologies are also summarized. The test system and protocol were judged practical and very useful. The test results indicate that one measurement technology can measure OA flow rates with errors of 20% or less without a field-based calibration, as long as the OA velocities are sufficient to provide an accurately measurable pressure signal. The test results for a second measurement technology are similar; however, a difficult field-based calibration relating the OA flow rate with the pressure signal would be required to reduce errors below approximately 30%. The errors in OA flow rates measured with the third measurement technology, that uses six electronic airspeed sensors downstream of the OA inlet louver, exceeded 100%; however, these errors could be substantially reduced through a difficult field based calibration. The effects of wind on the accuracy of these measurement technologies still needs to be evaluated. | |
| Report number: LBNL-53212 | Year: 2003 |
| Title: Performance and Costs of Particle Air Filtration in HVAC Supply Airstreams | Published in: HPAC Engineering, Volume 75, Pages 24-36. |
| Authors: Fisk, W.J., Faulkner, D., Palonen, J., Seppänen, O. | Type: Journal Article |
| Abstract: This paper uses a model, and data on particle size distributions, filter efficiencies, and particle deposition rates to estimate the reductions in the indoor mass concentrations of particles attainable from use of filters in HVAC supply airstreams. Additionally, the energy and total costs of the filtration options are estimated. Predicted reductions in cat and dust-mite allergen concentrations range from 20% to 60%. Increasing filter efficiencies above approximately ASHRAE Dust Spot 65% (MERV 11) does not significantly reduce predicted indoor concentrations of these allergens. For environmental tobacco smoke particles and outdoor fine mode particles, calculations indicate that relatively large, e.g., 80%, decreases in indoor concentrations are attainable with practical filter efficiencies. Increasing the filter efficiency above ASHRAE Dust Spot 85% (MERV 13) results in only modest incremental decreases in concentrations. Energy costs and total costs do not always increase for higher efficiency filters. Total estimated filtration costs of $0.70 to $1.80 per person per month are insignificant relative to salaries, rent, or health insurance costs. | |
| Report number: LBNL-53201 | Year: 2003 |
| Title: Designing for Smoking Rooms | Published in: ASHRAE Journal, Volume 45, Pages 26-32. |
| Authors: Alevantis, L., Wagner, J., Fisk, W.J., Sullivan, D.P., Faulkner, D. | Type: Journal Article |
| Abstract: No Abstract available. | |
| Report number: LBNL-51836 | Year: 2002 |
| Title: A Pilot Study Of Energy Efficient Air Cleaning For Ozone | Published in: |
| Authors: Gundel, L.A., Sullivan, D.P., Katsapov, G.Y., Fisk, W.J. | Type: Report |
| Abstract: This report explores the feasibility of energy efficient low cost ozone removal from indoor air by examining carbon-based filtration options. Several candidate carbon-based materials and configurations were assessed by review of previous work and performance calculations. In addition, a laboratory pilot study was undertaken with the material that showed the most potential promise. This material was a commercially available filter that contained a thin layer of small activated carbon particles in a pleated configuration. For three months ozone (113 ? 13 ppm) in particle-filtered ambient air passed through the filter at a realistic ventilation system face velocity of 0.5 m s-1. Ozone was injected upstream of the filter, and its concentration was monitored continuously upstream and downstream of the filter, as well as in the incoming ambient air. Throughout the three-month period, continuous measurements were made of the ambient temperature and humidity, as well as flow rate and pressure drop through the filter. The ozone removal efficiency was initially 96% and remained at 50% or higher for two and a half months. The estimated ozone removal capacity, before the efficiency dropped below 50%, was 0.3 g ozone per gram carbon. The pressure drop of the air flowing through the ozone filter was 26 Pa. Based on the size, efficiency, measured lifetime, and pressure drop of the ozone filter, it appears that ozone air cleaning may be practical in commercial air handling systems. | |
| Report number: LBNL-49356 | Year: 2002 |
| Title: Worker productivity and ventilation rate in a call center: analyses of time-series data for a group of workers | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 790-795. |
| Authors: Fisk, W.J., Price, P.N., Faulkner, D., Sullivan, D.P., Dibartolomeo, D., Federspiel, C., Liu, L., Lahiff, M. | Type: Conference Proceedings |
| Abstract: In previous studies, increased ventilation rates and reduced indoor carbon dioxide concentrations have been associated with improvements in health at work and increased performance in work-related tasks. Very few studies have assessed whether ventilation rates influence performance of real work. This paper describes part one of a two-part analysis from a productivity study performed in a call center operated by a health maintenance organization. Outside air ventilation rates were manipulated, indoor air temperatures, humidities, and carbon dioxide concentrations were monitored, and worker performance data for advice nurses, with 30-minute resolution, were analyzed via multivariate linear regression to look for an association of performance with building ventilation rate, or with indoor carbon dioxide concentration (which is related to ventilation rate per worker). Results suggest that the effect of ventilation rate on worker performance in this call center was very small (probably less than 1%) or nil, over most of the range of ventilation rate experienced during the study (roughly 12 L s-1 to 48 L s-1 per person). However, there is some evidence suggesting performance improvements of 2% or more when the ventilation rate per person is very high, as indicated by indoor CO2 concentrations exceeding outdoor concentrations by less than 75 ppm. | |
| Report number: LBNL-47833 | Year: 2002 |
| Title: Performance and cost of particle air filtration technologies | Published in: Indoor Air, Volume 12, Pages 223-234. |
| Authors: Fisk, WJ, Faulkner, D, Palonen, J, Seppänen, O | Type: Journal Article |
| Abstract: This paper predicts the reductions in the indoor mass concentrations of particles attainable from use of filters in building supply airstreams and also from use of stand-alone fan-filter units. Filters with a wide efficiency range are considered. Predicted concentration reductions are provided for indoor-generated particles containing dust mite and cat allergen, for environmental tobacco smoke particles, and for outdoor- air fine mode particles. Additionally, this paper uses a simple model and available data to estimate the energy and total costs of the filtration options. Predicted reductions in cat and dust-mite allergen concentrations range from 20% to 80%. To obtain substantial, e.g., 50%, reductions in indoor concentrations of these allergens, the rate of airflow through the filter must be at least a few indoor volumes per hour. Increasing filter efficiencies above approximately ASHRAE Dust Spot 65% does not significantly reduce predicted indoor concentrations of these allergens. For environmental tobacco smoke particles and outdoor fine mode particles, calculations indicate that relatively large, e.g., 80%, decreases in indoor concentrations are attainable with practical filter efficiencies and flow rates. Increasing the filter efficiency above ASHRAE 85% results in only modest predicted incremental decreases in indoor concentration. Energy costs and total costs can be similar for filtration using filters with a wide range of efficiency ratings. Total estimated filtration costs of approximately $0.70 to $1.80 per person per month are insignificant relative to salaries, rent, or health insurance costs. | |
| Report number: LBNL-49939 | Year: 2002 |
| Title: Ventilation efficiencies of a desk-edge-mounted task ventilation system | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 4, Pages 1060-1065. |
| Authors: Faulkner, D., Fisk, W.J., Sullivan, D.P., Lee, S.M. | Type: Conference Proceedings |
| Abstract: In chamber experiments, we investigated the effectiveness of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15o to 45o from horizontal), and the supply flow rate of (3.5 to 6.5 L s-1). Using the tracer gas step-up and step- down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air at the mannequin's face) ranged from 1.4 to 2.7, which is higher than typically reported for commercially available task ventilation or displacement ventilation systems. | |
| Report number: LBNL-49026 | Year: 2001 |
| Title: Report on HVAC Option Selections for a Relocatable Classroom Energy and Indoor Environmental Quality Field Study | Published in: |
| Authors: Apte, M.G., Delp, W.W., Diamond, R.C., Hodgson, A.T., Kumar, S., Shendell, D.G., Sullivan, D.P., Fisk, W.J. | Type: Journal Article |
| Report number: LBNL-43174 | Year: 1999 |
| Title: Particle Concentrations in an Air-Conditioned Office Building with Normal and High Efficiency Filtration | Published in: Proceedings of the Indoor Air '99, Edinburgh, Scotland, Volume 4, Pages 19-24. |
| Authors: Fisk, W.J., Sullivan, D., Mendell, M. | Type: Conference Proceedings |
| Report number: LBNL-42700 | Year: 1999 |
| Title: Ventilation Efficiencies of Desk-Mounted Task/Ambient Conditioning Systems | Published in: Proceedings of the Indoor Air '99 Conference, Edinburgh, Scotland, Volume 9, Pages 273-281. |
| Authors: Faulkner, D., Fisk, W.J., Sullivan, D., Wyon, D.P. | Type: Conference Proceedings |
| Report number: LBNL-42597 | Year: 1999 |
| Title: Ventilation Efficiencies of Task Air Conditioning Systems With Desk-Mounted Air Supplies | Published in: Proceedings of the Indoor Air '99, Edinburgh, Scotland, Volume 2, Pages 356-361. |
| Authors: Faulkner, D., Fisk, W.J., Sullivan, D, Wyon, D.P. | Type: Conference Proceedings |
| Report number: LBNL-41698 | Year: 1998 |
| Title: Sensor based demand controlled ventilation: a review | Published in: Energy and Buildings, Volume 29, Pages 35-44. |
| Authors: Fisk, W.J., de Almeida, A.T. | Type: Journal Article |
| Report number: LBNL-40223 | Year: 1998 |
| Title: Characterizing Building Ventilation with the Pollutant Concentration Index: Results from Field Studies | Published in: Proceedings of the ASHRAE IAQ and Energy 1998, Pages 27-35. |
| Authors: Faulkner, D. F., Fisk, W.J., Sullivan, D.P., Thomas, J.M., Persily, A. | Type: Conference Proceedings |
| Report number: LBNL-40292 | Year: 1997 |
| Title: Air Change Effectiveness and Pollutant Removal Efficiency During Adverse Mixing Conditions | Published in: Indoor Air, Volume 7, Pages 55-63. |
| Authors: Fisk, W.J., Faulkner, D., Sullivan, D.P., Bauman, F. | Type: Journal Article |
| Report number: LBNL-38869 | Year: 1996 |
| Title: Energy Savings in Cleanrooms from Demand-Controlled Filtration | Published in: Journal of the Institute of Environmental Sciences, Volume 39, Pages 21-27. |
| Authors: Faulkner, D., Fisk, W.J., Walton, J.T. | Type: Journal Article |
| Report number: LBL-36131 | Year: 1995 |
| Title: Indoor Airflow and Pollutant Removal in a Room With Floor-Based Task Ventilation: Results of Additional Experiments | Published in: Building and Environment, Volume 30, Pages 323-332. |
| Authors: Faulkner, D., Fisk, W.J., Sullivan, D.P. | Type: Journal Article |
| Report number: LBNL-62203 | Year: 2007 |
| Title: Evaluation of a Combined Ultraviolet Photocatalytic Oxidation (UVPCO) / Chemisorbent Air Cleaner for Indoor Air Applications | Published in: |
| Authors: Hodgson, A.T., Destaillats, H., Hotchi, T., Fisk, W.J. | Type: Report |
| Abstract: We previously reported that gas-phase byproducts of incomplete oxidation were generated when a prototype ultraviolet photocatalytic oxidation (UVPCO) air cleaner was operated in the laboratory with indoor-relevant mixtures of VOCs at realistic concentrations. Under these conditions, there was net production of formaldehyde and acetaldehyde, two important indoor air toxicants. Here, we further explore the issue of byproduct generation. Using the same UVPCO air cleaner, we conducted experiments to identify common VOCs that lead to the production of formaldehyde and acetaldehyde and to quantify their production rates. We sought to reduce the production of formaldehyde and acetaldehyde to acceptable levels by employing different chemisorbent scrubbers downstream of the UVPCO device. Additionally, we made preliminary measurements to estimate the capacity and expected lifetime of the chemisorbent media. For most experiments, the system was operated at 680 – 780 m3/h (400 – 460 cfm). A set of experiments was conducted with common VOCs introduced into the UVPCO device individually and in mixture. Compound conversion efficiencies and the production of formaldehyde and acetaldehyde were determined by comparison of compound concentrations upstream and downstream of the reactor. There was general agreement between compound conversions efficiencies determined individually and in the mixture. This suggests that competition among compounds for active sites on the photocatalyst surface will not limit the performance of the UVPCO device when the total VOC concentration is low. A possible exception was the very volatile alcohols, for which there were some indications of competitive adsorption. The results also showed that formaldehyde was produced from many commonly encountered VOCs, while acetaldehyde was generated by specific VOCs, particularly ethanol. The implication is that formaldehyde concentrations are likely to increase when an effective UVPCO air cleaner is used in buildings containing typical VOC sources. The magnitude of the expected increase will depend upon a number of interrelated factors. Series of experiments were conducted to determine if the oxidizer, sodium permanganate (NaMnO4•H2O), has sufficient reaction rates and capacity to counteract formaldehyde and acetaldehyde production and enable a 50 % reduction in building ventilation rate without net increases in indoor aldehyde concentrations. A commercially produced filter element and two laboratory-fabricated media beds containing NaMnO4•H2O chemisorbent media were evaluated. The effectiveness of a device for removal of formaldehyde, acetaldehyde and other VOCs was determined by measurement of concentrations immediately upstream and downstream of the device. In some experiments, conversion efficiencies and byproduct generation by the UVPCO device also were determined. Six experiments were conducted with the commercial filter element installed downstream of the UVPCO reactor. Eleven experiments were conducted with a single panel media bed (30 cm by 61 cm by 2.5 cm deep) installed downstream of the UVPCO reactor; in these, the effects of temperature and air residence time on conversion efficiency were examined. Two experiments were conducted with a four-panel, folded, media bed (approximately four times the size of the single panel bed) installed downstream of the reactor. Because the commercial unit contained activated carbon as an additional component, it was effective at removing lower volatility compounds that typically have low oxidation rates in the UVPCO reactor. The filter element also met the minimum efficiency objective for formaldehyde. However, the removal of acetaldehyde was less than required. The air residence time in the single panel bed was not optimized as the removal efficiencies for both formaldehyde and acetaldehyde were strongly inversely related to the air flow rate through the device. In addition, the acetaldehyde removal efficiency decreased to less than 10 % with extended use of the device. The folded bed was considerably more effective; formaldehyde was removed with greater than 90 % efficiency, and acetaldehyde was removed at about 70 % efficiency. With the combined UVPCO/chemisorbent system, the net removal efficiencies for formaldehyde and acetaldehyde were 90 % and 40 %, respectively. Two pairs of replicated experiments were conducted with the UVPCO system operating within a 50-m3 environmental chamber in a simulated HVAC mode with recirculation of chamber air. For one pair, the UVPCO air cleaner was operated alone, and for the other, the combined system of UVPCO air cleaner plus a downstream chemisorbent was used. The results showed that the chemisorbent media contributed substantially to the removal of VOCs in this mode. Concentrations were pulled down within the first hour. Net reductions for formaldehyde and acetaldehyde at near steady-state conditions were in the range of 50 to 70 %. From an analysis of NaMnO4•H2O in new and used media and the conditions of the experiments with the single panel media bed, we estimated that, on average, about nine moles of NaMnO4•H2O were needed to mineralize one mole of VOCs, and about three moles of the reactant were needed to mineralize one mole of carbon. These values were used to make estimates of the media consumption rate for the experimental conditions and for a hypothetical building application. In summary, the use of a multi-panel, folded scrubber filled with NaMnO4•H2O chemisorbent media downstream of the prototype UVPCO air cleaner effectively counteracted the generation of formaldehyde and acetaldehyde due to incomplete oxidation of VOCs in the UVPCO reactor. Thus, this combined UVPCO air cleaner and chemisorbent system appears to have sufficient VOC removal efficiency to enable a 50 % reduction in ventilation rate without increasing indoor aldehyde concentrations. | |
| Report number: LBNL-59631 JArt | Year: 2007 |
| Title: Performance of ultra-violet Photocatalytic Oxidation for Indoor Air Cleaning Applications | Published in: Indoor Air, Volume 17, Pages 305-316. |
| Authors: Hodgson, A., Destaillats, H., Sullivan, D, Fisk, W.J. | Type: Journal Article |
| Abstract: Acceptable indoor air quality in office buildings may be achieved with less energy by combining effective air cleaning systems for volatile organic compounds (VOCs) with particle filtration than by relying solely on ventilation. For such applications, ultraviolet photocatalytic oxidation (UVPCO) systems are being developed for VOC removal. An experimental evaluation of a UVPCO system with tungsten oxide modified titanium dioxide as the photocatalyst is reported. The evaluation is unique in that it employed complex VOC mixtures. One of the mixtures contained 27 VOCs commonly found in office buildings, and the other comprised 10 VOCs emitted by cleaning products, in both cases at realistically low concentrations. VOC conversion efficiencies varied over a broad range, usually exceeded 20%, and were as high as ~80%. Conversion efficiency generally diminished with increased air flow rate, and followed the approximate order: alcohols and glycol ethers > aldehydes, ketones, and terpene hydrocarbons > aromatic and alkane hydrocarbons > halogenated aliphatic hydrocarbons. Conversion efficiencies were observed to correlate with the Henry's law constant of the studied VOCs more closely than with other physicochemical parameters. An empirical model based on the Henry's law constant and the gas-phase reaction rate with hydroxyl radical facilitated an estimate of pseudo-first order photocatalytic reaction rates for the studied VOCs. Significant amounts of formaldehyde and acetaldehyde were produced due to incomplete mineralization suggesting that safe deployment of UVPCO in buildings likely will require mitigation methods for these undesirable pollutants. | |
| Report number: LBNL-58250 | Year: 2006 |
| Title: Cleaning Products and Air Freshners: Emissions and Resulting Concentrations of Glycol Ethers and Terpenoids | Published in: Indoor Air, Volume 16, Pages 179-191. |
| Authors: Singer, B.C., Destaillats, H., Hodgson, A., Nazaroff, W. | Type: Journal Article |
| Abstract: Experiments were conducted to quantify emissions and concentrations of glycol ethers and terpenoids from cleaning product and air freshener use in a 50-m3 room ventilated at ~0.5 h-1. Five cleaning products were applied full-strength (FS); three were additionally used in dilute solution. FS application of pine-oil cleaner (POC) yielded 1-h concentrations of 10-1300 ìg m-3 for individual terpenoids, including á-terpinene (90-120), d-limonene (1000-1100), terpinolene (900-1300), and á-terpineol (260-700). One-hour concentrations of 2-butoxyethanol and/or d-limonene were 300-6000 µg m-3 after FS use of other products. During FS application including rinsing with sponge and wiping with towels, fractional emissions (mass volatilized / dispensed) of 2-butoxyethanol and d-limonene were 50-100% with towels retained, ~25-50% when towels were removed after cleaning. Lower fractions (2-11%) resulted from dilute use. Fractional emissions of terpenes from FS use of POC were ~35-70% with towels retained, 20-50% with towels removed. During floor cleaning with dilute solution of POC, 7-12% of dispensed terpenes were emitted. Terpene alcohols were emitted at lower fractions: 7-30% (FS, towels retained), 2-9% (FS, towels removed), and 2-5% (dilute). During air-freshener use, d-limonene, dihydromyrcenol, linalool, linalyl acetate, and è-citronellol) were emitted at 35-180 mg d-1 over three days while air concentrations averaged 30-160 µg m-3. | |
| Report number: LBNL-59293 | Year: 2006 |
| Title: Indoor Air Quality Impacts of a Peak Load Shedding Strategy for a Large Retail Building | Published in: |
| Authors: Hotchi, T., Hodgson, A., Fisk, W. J. | Type: Report |
| Report number: LBNL-59631 | Year: 2006 |
| Title: Evaluation of Ultra-Violet Photocatalytic Oxidation for Indoor Air Applications | Published in: Proceedings of Healthy Buildings 2006 Conference, Volume 2, Pages 243-248. |
| Authors: Hodgson, A., Sullivan, D, Fisk, W.J. | Type: Conference Proceedings |
| Abstract: This paper summarizes three analyses of data on building-related environmental factors and occupant symptoms collected from 100 representative large U.S. office buildings. Using multivariate logistic regression models, we found increased occupant symptoms associated with a number of building-related factors, including lower ventilation rates even at the current guideline levels, lack of scheduled cleaning for air-conditioning drain pans and cooling coils, poor condition of cooling coils, poorly maintained humidification systems, and lower outdoor air intake height. Some expected relationships were not found, and several findings were opposite of expected. Although requiring replication, these findings suggest preventive actions to reduce occupant symptoms in office buildings. | |
| Report number: LBNL-60254 | Year: 2006 |
| Title: Photocatalytic Reactor System with Tungsten Oxide-Modified Titanium Dioxide for Indoor Air Applications | Published in: The 11th International Conference on Ti02 Photocatalysis: Fundamentals and Applications (Ti02-11). |
| Authors: Hodgson, A., Destaillats, H., Sullivan, D, Fisk, W.J. | Type: Conference Proceedings |
| Report number: LBNL-60162 | Year: 2006 |
| Title: Sorbent-based gas phase air cleaning for VOCs in Commercial Buildings. | Published in: |
| Authors: Fisk, W.J. | Type: Report |
| Report number: LBNL-57505 | Year: 2006 |
| Title: Secondary pollutants from ozone reaction with nicotine on surfaces | Published in: Proceedings of Healthy Buildings 2006 Conference, Pages A-451. |
| Authors: Destaillats, H., Singer, B.C., Gundel, L A., E. de Oliveira Fernandes, M. Gameiro da Silva, J. Rosado Pinto | Type: Conference Proceedings |
| Report number: LBNL-57050 | Year: 2005 |
| Title: Acid-Base Interactions Of Nicotine And Pyridine On Surfaces | Published in: Proceedings of The 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume 2(4), Pages 1700-1704. |
| Authors: Destaillats, H., Singer, B.C., Lee, S.K., Gundel, L A. | Type: Conference Proceedings |
| Abstract: Two different experimental approaches were employed to gain insight into the molecular interactions of nicotin e and pyridine with simple and well-characterized materials. We investigated nicotine desorption from Teflon and cotton surfaces in a flow chamber experiment and developed an ATR-FTIR spectrophotometric method to study the molecular association of pyridine with materials representative of certain indoor surfaces (cellulose and gypsum). The experimental results suggest the presence of two sorptive states for volatile amines. Spectroscopic evidence for acid-base interactions with surfaces is consistent with the observed desorption behavior. | |
| Report number: LBNL-57038 | Year: 2005 |
| Title: Secondary Pollutants From Cleaning Products And Air Fresheners In The Presence Of Ozone | Published in: Proceedings of The 10th International Conference on Indoor Air Quality and Climate - Indoor Air 2005, Volume 2(9), Pages 2081-2085. |
| Authors: Destaillats, H., Singer, B.C., Coleman, B.K., Lunden, M.M., Hodgson, A.T., Weschler, C.J., Nazaroff, W.W. | Type: Conference Proceedings |
| Abstract: This study investigated secondary air pollutants formed from reactions between constituents of terpene-containing household products and ozone. Gas-phase emissions from three different products were introduced along with ozone into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenes, terpenoids and oxidation products were measured. When the formulation contained more than one reactive VOC, their relative consumption by ozone was proportional to the initial reactant concentrations and to the rate constants of the respective terpene-ozone reactions. Formaldehyde was a predominant oxidation byproduct for the three studied products. Acetaldehyde and acetone were also detected when two of the products were exposed to ozone. A scanning mobility particle sizer measured particle nucleation events followed by a significant degree of ultrafine particle growth immediately upon mixing of reactants. Elevated concentrations of OH radicals generated by terpene ozonolysis were also measured. | |
| Report number: LBNL-58824 | Year: 2005 |
| Title: Improving Ventilation and Saving Energy: Relocatable Classroom Field Study Interim Report | Published in: |
| Authors: Apte, M G., Faulkner, D, Hodgson, A., Hotchi, T., Spears, M., Sullivan, D, Wang, D. | Type: Report |
| Abstract: The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many classrooms are under-ventilated, and public concerns about indoor environmental quality in classrooms. This report presents an interim status update and preliminary findings from energy and indoor environmental quality (IEQ) measurements in sixteen relocatable classrooms in California. The field study includes measurements of HVAC energy use, ventilation rates, and IEQ conditions. Ten of the classrooms were equipped with a new HVAC technology and six control classrooms were equipped with a standard HVAC system. Energy use and many IEQ parameters have been monitored continuously, while unoccupied acoustic measurements were measured in one of four planned seasonal measurement campaigns. Continuously monitored data are remotely accessed via a LonWorks® network and stored in a relational database at LBNL. Preliminary results are presented here. | |
| Report number: LBNL-52520 | Year: 2004 |
| Title: Comparison of predicted and derived measures of volatile organic compounds inside four relocatable classrooms due to identified interior finish sources | Published in: Indoor Air (Supplement 8), Volume 14, Pages 135-144. |
| Authors: Hodgson, A.T., Shendell, D.G., Fisk, W.J., Apte, M.G. | Type: Journal Article |
| Abstract: Indoor exposures to toxic and odorous volatile organic compounds (VOCs) are of general concern. Recently, VOCs in portable or relocatable classrooms (RCs) have received particular attention. However, very little was known about indoor environmental quality (IEQ) and the sources, composition, and indoor concentrations of VOCs in RCs. This project task focused on developing and demonstrating a process for selecting interior finish materials for RCs that have relatively low impacts with respect to their emissions of toxic and odorous VOCs. This task was part of a larger project to demonstrate the potential for simultaneous improvements in IEQ and energy efficiency in four new RCs equipped both with a continuously ventilating advanced heating, ventilating, and air conditioning system (HVAC) and a standard HVAC system. These HVACs were operated on alternate weeks. One RC per pair was constructed with standard interior finish materials, and the other included alternate interior materials identified in our prior laboratory study to have low VOC emissions. The RCs were sited in side-by-side pairs at two elementary schools in distinct northern California climate zones. Classroom VOC emission rates (mg hr-1) and concentrations were predicted based on VOC emission factors (µg m-2 hr-1) measured for individual materials in the laboratory, the quantities of installed materials and design ventilation rates. Predicted emission rates were compared to values derived from classroom measurements of VOC concentrations and ventilation rates made at pre-occupancy, eight weeks, and 27 weeks. Predicted concentrations were compared to measured integrated VOC indoor minus outdoor concentrations during school hours in the fall cooling season with the advanced HVAC operated. These measured concentrations also were compared between standard and material-modified RCs. Our combined laboratory and field process proved effective by correctly predicting that IEQ impacts of material VOC emissions would be minor when RCs were ventilated at or above code-minimum requirements. Assuming code-minimum ventilation rates are maintained, the benefits attributable to the use of alternate interior finish materials in RC's constructed by the manufacturer associated with this study are small, implying that it is not imperative to use such alternative finishing materials. However, it is essential to avoid materials that can degrade IEQ, and the results of this study demonstrate that laboratory-based material testing combined with modeling and field validation can help to achieve that aim. | |
| Report number: LBNL-51715 | Year: 2003 |
| Title: Volatile organic compounds in indoor air: A review of concentrations measured in North America since 1990 | Published in: |
| Authors: Hodgson, A.T., Levin, H. | Type: Report |
| Abstract: Central tendency and upper limit concentrations of volatile organic compounds (VOCs) measured in indoor air are summarized and reviewed. Data were obtained from published cross-sectional studies of residential and office buildings conducted in North America from 1990 through 2001. VOC concentrations in existing residences reported in 12 studies comprise the majority of the data set. Central tendency and maximum concentrations are compared between new and existing residences and between existing residences and office buildings. Historical changes in indoor VOC concentrations since the Clean Air Act Amendments of 1990 are explored by comparing the current data set with two published reviews of previous data obtained primarily in the 1980s. These historical comparisons suggest average indoor concentrations of some toxic air contaminants, such as 1,1,1-trichloroethane have decreased. | |
| Report number: LBNL-53308 | Year: 2003 |
| Title: Classification of measured indoor volatile organic compounds based on noncancer health and comfort considerations | Published in: |
| Authors: Hodgson, A.T., Levin, H. | Type: Report |
| Abstract: Building occupants are exposed to complex mixtures of air pollutants including many volatile organic compounds (VOCs). A recent review summarized the central tendency and upper limit indoor VOC concentrations measured in North American residences and office buildings since 1990. Although this database is limited in many respects, it serves as a useful starting point for evaluating the potential health and comfort effects of indoor VOC exposures. Excluding cancer and birth defects, the primary concern is chronic inhalation exposure to toxicants that can cause serious health problems. Additionally, building occupants react to the quality of indoor air through their sensory perceptions and frequently experience unpleasant odors and irritation of the eyes and upper respiratory tract. In this paper, we conduct a simple screening-level assessment of indoor VOC concentrations. We compare measured VOC concentrations to published odor thresholds, sensory irritation levels derived for the general population, and noncancer chronic health guidelines. Hazard quotients are individually calculated for these three effects by dividing maximum or derived 95th percentile VOC concentrations by our selected best estimates of guidance levels for the general population. These results provide a basis for broadly classifying commonly encountered VOCs into groups according to the likelihood that they will produce effects among building occupants. This methodology shows that only a small number of the more than 100 reported VOCs exceed levels that are likely to be of concern with respect to the health and comfort endpoints considered. Although data is lacking for a number of odorous compounds potentially present in buildings, the results indicate that carboxylic acids, higher molecular weight aldehydes and less volatile aromatic hydrocarbons are most likely to be perceived by olfaction and that there is more probability of detection in residences than in offices. Sensory irritation levels were approached or exceed by only a very small number of relatively potent, reactive VOCs. Of these, acrolein was by far the most potent irritant. Although more detailed consideration of the underlying toxicological data is needed, the results suggest that only a small number of commonly measured VOCs, when considered singly, are likely to produce serious irreversible health effects not associated with cancer. These compounds include lower molecular weight aldehydes, and several aromatic hydrocarbons. Again, acrolein stands out as the most potent compound. Based on these results, we recommend that studies to characterize indoor VOC concentrations and exposures focus their resources on compounds that are most likely to impact occupants as determined by the study objectives. For a very few compounds, such as acrolein and formaldehyde, the evidence based on sensory irritation and chronic toxicity appears sufficient to warrant efforts to reduce and control sources of these compounds in buildings. | |
| Report number: LBNL-52497 | Year: 2003 |
| Title: Effect of Outside Air Ventilation Rate on Volatile Organic Compound Concentrations in a Call Center | Published in: Atmospheric Environment, Volume 37, Pages 5517-5528. |
| Authors: Hodgson, A.T., Faulkner, D., Sullivan, D.P., Dibartolomeo, D.L., Russell, M.L., Fisk, W.J. | Type: Journal Article |
| Abstract: A study of the relationship between outside air ventilation rate and concentrations of volatile organic compounds (VOCs) generated indoors was conducted in a call center office building. The building, with two floors and a floor area of 4,600 m2, was located in the San Francisco Bay Area, CA. Ventilation rates were manipulated with the building's four air handling units (AHUs). VOC concentrations in the AHU returns were measured on seven days during a 13-week period. VOC emission factors were determined for individual zones on days when they were operating at near steady-state conditions. The emission factor data were subjected to principal component (PC) analysis to identify groups of co-varying compounds. Potential sources of the PC vectors were ascribed based on information from the literature supporting the associations. Two vectors with high loadings of compounds including formaldehyde, 2,2,4-trimethyl-1,3- pentanediol monoisobutyrate, decamethylcyclopentasiloxane (d5 siloxane), and isoprene likely identified occupant-related sources. One vector likely represented emissions from building materials. Another vector represented emissions of solvents from cleaning products. The relationships between indoor minus outdoor VOC concentrations and ventilation rate were qualitatively examined for eight VOCs. Of these, acetaldehyde and hexanal, which were likely associated with material sources, and d5 siloxane exhibited general trends of higher concentrations at lower ventilation rates. For other compounds, the operation of the building and variations in pollutant generation and removal rates apparently combined to obscure the inverse relationship between VOC concentrations and ventilation. This result emphasizes the importance of utilizing source control measures, in addition to adequate ventilation, to limit concentrations of VOCs of concern in office buildings. | |
| Report number: LBNL-47095 | Year: 2002 |
| Title: Modeling the Reversible Sink Effect in Response to Transient Contaminant Sources | Published in: Indoor Air, Volume 12, Pages 184-190. |
| Authors: Zhao, D, Little, J.C., Hodgson, A.T. | Type: Journal Article |
| Abstract: A physically based diffusion model is used to evaluate the sink effect of diffusion-controlled indoor materials and to predict the transient contaminant concentration in indoor air in response to several time-varying contaminant sources. For simplicity, it is assumed that the predominant indoor material is a homogeneous slab, initially free of contaminant, and that the air within the room is well mixed. The model enables transient volatile organic compound (VOC) concentrations to be predicted based on the material/air partition coefficient (K) and the material-phase diffusion coefficient (D) of the sink. Model predictions are made for four scenarios, each mimicking a realistic situation in a building. Styrene, phenol, and naphthalene are used as representative VOCs. A styrene butadiene rubber (SBR) backed carpet, vinyl flooring (VF), and a polyurethane foam (PUF) carpet cushion are considered as typical indoor sinks. In scenarios involving a sinusoidal VOC input and a double exponential decaying input, the model predicts that the sink has a modest impact for SBR/styrene, but that the effect increases for VF/phenol and PUF/naphthalene. In contrast, for an episodic chemical spill, SBR is predicted to reduce the peak styrene concentration considerably. A parametric study reveals that for systems involving a high equilibrium factor (K), the kinetic factor (D) will govern the shape of the resulting gas-phase concentration profile. On the other hand, for systems with a relaxed mass transfer resistance, K will dominate the profile. | |
| Report number: Abstract (no LBNL number) | Year: 2002 |
| Title: VOCs in New Relocatable Classrooms: Assessment of School-Day Exposures Comparing Interior Finish Materials and HVAC Systems | Published in: Epidemiology, Volume 13, Pages S143. |
| Authors: Shendell, D.G., Hodgson, A.T., Lee, S.M, Apte, M.G., Sullivan, D.P., Hotchi, T., Fisk, W.J. | Type: Journal Article |
| Abstract: The prevalence of relocatable classrooms (RCs) at schools is rising due to initiatives to reduce K-3 class size, and limited capital resources. Concerns regarding inadequate ventilation and indoor air quality in RCs have been raised. Since students and teachers spend the majority of a 7-8 hour school day inside classrooms, indoor contaminant concentrations are assumed to drive personal school-day exposures. We conducted a demonstration project in new relocatable classrooms (RCs) during the 2001-02 school year to address these issues. The benefits of upgrades including an energy efficient heating, ventilation, and air conditioning (HVAC) system and alternate interior finish materials were investigated. One specific goal was to demonstrate that improved ventilation coupled with source reduction could lower indoor concentrations of toxic and odorous volatile organic compounds (VOCs), including formaldehyde and acetaldehyde. Four new 24' x 40' (960 ft2) RCs were constructed and sited in pairs at an elementary school campus in each of two participant school districts (SD) in Northern California. Each RC was equipped with a standard HVAC system with intermittent 25-50% outdoor air ventilation and an energy-efficient advanced system providing continuous 100% ventilation (15 cfm/occupant). Alternate carpets, wall panels, and ceiling panels were installed in two classrooms -- one in each pair -- based on the results of a laboratory study of VOC emissions from standard and alternate materials. The two HVAC systems were operated on alternate weeks. School day-integrated air samples were collected indoors and outdoors mid-week during eight and nine weeks in the cooling (fall) and heating (winter) seasons, respectively. VOCs were collected on sorbent media and analyzed by thermal desorption GC/MS. Aldehydes were collected on DNPH treated silica gel cartridges and analyzed by HPLC. The effects of material selection on VOC concentrations were evaluated by emissions studies conducted prior to and after the first eight weeks of occupancy and by a comparison of occupied-hour classroom concentrations with the advanced HVAC operational. Slightly lower phenol and 1-methyl-2-pyrrolidinone concentrations in source-modified RCs were attributed to the alternate wall panel. Slightly lower formaldehyde concentrations in these RCs were attributed to the lower- emitting ceiling panels. At one school, teaching materials brought in after the school year began were discovered to be formaldehyde sources. Across SD and RCs in the cooling season, mean concentrations of formaldehyde were 14.1 +/- 6.6 and 30.4 +/- 6.9 µg m-3 during advanced and standard HVAC system operation, respectively. Likewise, acetaldehyde mean concentrations were 6.9 +/- 4.7 and 13.7 +/- 3.7 µg m-3, respectively. Similar reductions were observed for toluene and phenol. Results suggest improved continuous ventilation provided by the advanced HVAC outweighed source reduction as a VOC control measure in these new RCs. | |
| Report number: LBNL-49535 | Year: 2002 |
| Title: Effect of outside air ventilation rate on VOC concentrations and emissions in a call center | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 2, Pages 168-173. |
| Authors: Hodgson, A.T., Faulkner, D., Sullivan, D.P., DiBartolomeo, D.L., Russell, M.L., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: A study of the relationship between outside air ventilation rate and concentrations of VOCs generated indoors was conducted in a call center. Ventilation rates were manipulated in the building's four air handling units (AHUs). Concentrations of VOCs in the AHU returns were measured on 7 days during a 13- week period. Indoor minus outdoor concentrations and emission factors were calculated. The emission factor data was subjected to principal component analysis to identify groups of co-varying compounds based on source type. One vector represented emissions of solvents from cleaning products. Another vector identified occupant sources. Direct relationships between ventilation rate and concentrations were not observed for most of the abundant VOCs. This result emphasizes the importance of source control measures for limiting VOC concentrations in buildings. | |
| Report number: LBNL-49536 | Year: 2002 |
| Title: Implementation of VOC Source Reduction Practices in a Manufactured House and in School Classrooms | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 3, Pages 576-581. |
| Authors: Hodgson, A.T., Apte, M.G., Shendell, D.G., Beal, D., McIlvaine, J.E.R. | Type: Conference Proceedings |
| Abstract: Detailed studies of a new manufactured house and four new industrialized relocatable school classrooms were conducted to determine the emission sources of formaldehyde and other VOCs and to identify and implement source reduction practices. Procedures were developed to generate VOC emission factors that allowed reasonably accurate predictions of indoor air VOC concentrations. Based on the identified sources of formaldehyde and other aldehydes, practices were developed to reduce the concentrations of these compounds in new house construction. An alternate ceiling panel reduced formaldehyde concentrations in the classrooms. Overall, the classrooms had relatively low VOC concentrations. | |
| Report number: LBNL-48490 | Year: 2001 |
| Title: Predicted concentrations in new relocatable classrooms of volatile organic compounds emitted from standard and alternate interior finish materials | Published in: |
| Authors: Hodgson, A.T., Fisk, W.J., Shendell, D.G, Apte, M.G. | Type: Report |
| Report number: LBNL-42402 | Year: 1999 |
| Title: Common Indoor Sources of Volatile Organic Compounds: Emission Rates and Techniques for Reducing Consumer Exposures | Published in: |
| Authors: Hodgson, A.T. | Type: Report |
| Report number: | Year: 1996 |
| Title: Screening and Selecting Building Materials and Products Based on Their Emissions of Volatile Organic Compounds (VOCs) | Published in: ASTM STP 1287, Characterizing Sources of Indoor Air Pollution and Related Sink Effects, Pages 376-391. |
| Authors: Levin, H., Hodgson, A.T., Tichenor, B.A. | Type: Book Section |
| Report number: | Year: 1995 |
| Title: An Improved Inpregnated-filter Method for Measuring Low-level Concentrations fo Toluene Diiscoyanates in Air | Published in: |
| Authors: Mahanama, K. R. R., Hodgson, A. T. | Type: Journal Article |
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