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Report number: LBNL-62446	Year: 2008
Title: Energy implications of meeting ASHRAE Standard 62.2	Published in: ASHRAE Transactions, Volume 114, Pages 505-516.
Authors: Walker, I.S., Sherman, M.H.	Type: Journal Article
Abstract: The first and only nation-wide standard for residential ventilation in the United States is ASHRAE Standard 62.2-2004. This standard is being considered for adoption by various jurisdictions within the U.S. as well as by various voluntary programs. The adoption of 62.2 would require mechanical ventilation systems to be installed in virtually all new homes, but allows for a wide variety of design solutions. These solutions, however, may have a different energy costs and non-energy benefits. The authors have used a detailed simulation model to evaluate the energy impacts of common and proposed mechanical ventilation approaches for a variety of climates. These results separate the energy needed to ventilate into the energy needed to condition the ventilation air and the energy needed to distribute and/or temper the ventilation air. The results show that exhaust systems are generally the most energy efficient method of meeting the proposed requirements, mostly due to having the least increase in ventilation relative to an unvented home.

Report number: LBNL-57287	Year: 2006
Title: Homeowner Retrofit Guide	Published in:
Authors: Walker, I.S., McWilliams, J.	Type: Report

Report number: LBNL-61467	Year: 2006
Title: Residential Furnace Blower Performance	Published in:
Authors: Walker, I.S.	Type: Report

Report number: LBNL-59669	Year: 2006
Title: Public health benefits of end-use electrical energy efficiency in California.	Published in:
Authors: Lobscheid, A.B., McKone, T.E.	Type: Report

Report number: LBNL-57225	Year: 2005
Title: Duct Tape and Sealant Performance	Published in: ASHRAE Journal, Volume 47, Pages 34-41.
Authors: Walker, I.S., Sherman, M.H.	Type: Journal Article
Abstract: It’s in garages, kitchens, cars and boats. Books have been written about it. Wallets made from it are sold online. What is this infinitely useful product? Duct tape, of course. Although it serves so many purposes, it is important to understand how duct tape works for its ostensible purpose—to seal ducts. At the Lawrence Berkeley National Laboratory (LBNL), we have studied the durability and longevity of duct sealants for more than a decade and have created test methods for evaluating these properties. What we found was almost every product intended to be a duct sealant works—except duct tape. In this article, we summarize what we found and describe some of the work we did to evaluate duct tape and other sealants. The project began in the mid-1990s when California utilities were convinced that sealing air leaks in ducts was a cost effective measure for saving energy and ensuring good distribution of air throughout a building. They were concerned by the many anecdotal reports of duct sealant failures in the field and wanted to be able to recommend or require good sealing methods. They approached LBNL about creating a laboratory test method that would rate or rank duct sealants on their durability. We developed a test and expected to see a spectrum of results for different sealant products, but what we found surprised us. We found most types of sealants passed our test without any significant failures. These products included mastics, a wide spectrum of tape products with acrylic or butyl adhesives, and aerosol sealants. The only product class that failed consistently, and often catastrophically, was cloth-backed, rubber-adhesive tape—commonly called duct tape. As with many other building products, duct sealants are rated by Underwriters Laboratory using UL 181B safety standards. These standards are used by many jurisdictions as a requirement for duct sealants. When we began testing, few duct tapes existed that were UL 181B rated, but the ones we tested for sealant durability had similar failure characteristics to unrated tapes. Since that time, we have focused our efforts at improving the test procedures and trying to solve the problem of why duct tape could pass the UL 181B tests and not have sufficient longevity to be used in many field applications. To address this problem, we carried out several additional studies to understand the performance and durability of various duct sealing approaches.

Report number: LBNL-58742	Year: 2005
Title: Laboratory Evaluation of Residential Furnace Blower Performance	Published in:
Authors: Walker, I.S., Lutz, J.D.	Type: Report
Abstract: A testing program was undertaken at Lawrence Berkeley National Laboratory and an electric utility (Pacific Gas and Electric Co.) to compare the performance of furnace blowers. This laboratory testing program was undertaken to support potential changes to California Building Standards regarding in-field furnace blower energy use. This technical support includes identifying suitable performance metrics and target performance levels for use in standards. Five different combinations of blowers and residential furnaces were tested for air moving performance. Three different types of blower and motor combinations were tested in two different furnace cabinets. The blowers were standard forward-curved impellors and a prototype impeller with reverse-inclined blades. The motors were two 6-pole permanent split capacitor (PSC) single-phase induction motors, a brushless permanent magnet (BPM) motor and a prototype BPM designed for use with a prototype reverse-inclined impellor. The laboratory testing operated each blower and furnace combination over a range of air flows and pressure differences to determine air flow performance, power consumption and efficiency. Additional tests varied the clearance between the blower housing and the furnace cabinet, and the routing of air flow into the blower cabinet.

Report number: LBNL-57330	Year: 2005
Title: State-of-the-art in Residential and Small Commercial Air Handler Performance	Published in:
Authors: Walker, I.S.	Type: Report
Abstract: Although furnaces, air conditioners and heat pumps have become significantly more efficient over the last couple of decades, residential air handlers have not experienced similar improvement. The most common air handlers have efficiencies of only 10% to 15% (Phillips 1998, Gusdorf et al. 2002). These low efficiencies indicate that there is significant room for improvement of both electric motor and aerodynamic performance of air handler fans. The need to address this poor performance has been known for many years. For example, Ariewitz et al. (1983) developed a high efficiency blower for heat pump applications to address this issue. An important consideration in analyzing air handlers is the fact that essentially all of the wasted electricity is manifested as heat. This extra heat reduces air conditioning cooling and dehumidification performance and effectively acts as fuel switching for fossil fuelled furnaces. For electric furnaces, this heat substitutes directly for the electric resistance heating elements. For heat pumps, this heat substitutes for compressor-based high COP heating and effectively reduces the COP of the heat pump. Using a combination of field observations and engineering judgment we can assemble a list of the factors that lead to low air handler efficiency and potential solutions, as shown in Table 1. None of the problems require exotic or complex solutions and there are no technological barriers to adopting them. Some of the solutions are simple equipment swaps (using better electric motors), others require changes to the way the components are built (tighter tolerances) and others relate to HVAC equipment design (not putting large fans in small cabinets).

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-57406	Year: 2005
Title: Home Energy Article: A Systems Approach to Retrofiting Residential HVAC Systems	Published in:
Authors: McWilliams, J., Walker, I.S.	Type: Report
Abstract: Over the past couple of years, a Best Practices Guideline for Residential HVAC Retrofits (http://www.eere.energy.gov/buildings/building_america/pdfs/db/37801.pdf) has been developed by the US Department of Energy (DOE) to provide guidance for contractors in performing whole house retrofits. Because of the strongly cost-limited nature of retrofits, combined with the wide range of existing home performance, the DOE guideline has several levels of retrofit packages depending on the level of intervention that a homeowner can afford, or is justified by the condition of the home and its HVAC system. The packages are pre-selected combinations of individual retrofit activities that provide simple whole house guidance for contractors. This guideline has been evaluated by potential users such as contractors and weatherization experts. Part of this evaluation included a field pilot study applying the guidelines to eight test houses. The application of the guidelines to these houses resulted in feedback that helped to update and improve the guidelines. In order to have an independent assessment of the guidelines, two of the houses were evaluated by an independent energy efficiency contractor. One of the test houses was chosen to be retrofitted and had the Best Practices Guideline diagnostic screening tests repeated after the retrofit to compare pre and post-retrofit performance, as well as being the subject of extensive monitoring to determine the change in house performance due to the retrofit. More details of these test results and the application and development of the Retrofit Guide can be found in Walker [2003].

Report number: LBNL-53959	Year: 2005
Title: Validating and Improving the DeltaQ Duct Leakage Test	Published in: ASHRAE Transactions, Volume 110 - Pt. 2, Pages 741-751.
Authors: Dickerhoff, D., Walker, I, S., Sherman, M.	Type: Journal Article

Report number: LBNL-53549	Year: 2004
Title: Reducing Uncertainty for the DeltaQ Duct Leakage Test	Published in:
Authors: Walker, I.S., Sherman, M.H., Dickerhoff, D.J.	Type: Report
Abstract: The thermal distribution system couples the HVAC components to the building envelope, and shares many properties of the buildings envelope including moisture, conduction and most especially air leakage performance. Duct leakage has a strong influence on air flow rates through building envelopes (usually resulting in much greater flows than those due to natural infiltration) because unbalanced duct air flows and leaks result in building pressurization and depressurization. As a tool to estimate this effect, the DeltaQ duct leakage test has been developed over the past several years as an improvement to existing duct pressurization tests. It focuses on measuring the air leakage flows to outside at operating conditions that are required for envelope infiltration impacts and energy loss calculations for duct systems. The DeltaQ test builds on the standard envelope tightness blower door measurement techniques by repeating the tests with the system air handler off and on. The DeltaQ test requires several assumptions to be made about duct leakage and its interaction with the duct system and building envelope in order to convert the blower door results into duct leakage at system operating conditions. This study examined improvements to the DeltaQ test that account for some of these assumptions using a duct system and building envelope in a test laboratory. The laboratory measurements used a purpose-built test chamber coupled to a duct system typical of forced air systems in US homes. Special duct leaks with controlled air-flow were designed and installed into an airtight duct system. This test apparatus allowed the systematic variation of the duct and envelope leakage and accurate measurement of the duct leakage flows for comparison to DeltaQ test results. This paper will discuss the laboratory test apparatus design, construction and operation, the various analysis techniques applied to the calculation procedure and present estimates of uncertainty in measured duct leakage.

Report number: LBNL-56111	Year: 2004
Title: What's Up With Duct Tape?	Published in: Home Energy, Volume 21.
Authors: Walker, I.S., Sherman, M.H.	Type: Journal Article
Abstract: It's been a couple of years since we last wrote about duct tape in the pages of Home Energy and it is time to revisit this ever-popular issue. When last we left duct sealant durability issues, the Energy Performance of Buildings Group at Lawrence Berkeley National Laboratory (LBNL) had done an accelerated longevity test; we found that most everything worked except standard, cloth-backed rubber adhesive duct tape. In response, the State of California had limited the use of such tapes in new construction and manufacturers were considering developing new products. Several things have changed in the world of duct tape over the last couple of years. LBNL has completed another round of durability testing. There is a new version of Underwriters Laboratories (UL) 181B that now includes testing of the strapping that holds duct connections together. And there is a new American Society for Testing and Materials (ASTM) E2342-03 standard for testing the longevity of duct sealants.

Report number: LBNL-53592	Year: 2004
Title: Best practices guide for residential HVAC retrofits	Published in:
Authors: Walker, I.S.	Type: Report
Abstract: This best practices guide for residential HVAC system retrofits is aimed at contractors who want guidance on delivering energy efficient, cost effective and innovative products. It has been developed around the idea of having packages of changes to the building HVAC system and building envelope that are climate and house construction dependent. These packages include materials, procedures and equipment and are designed to remove some of the guesswork from a builder, contractor, installer or homeowner decisions about how best to carry out HVAC changes. The packages are not meant to be taken as rigid requirements - instead they are systems engineered guidelines that form the basis for energy efficient retrofits. Similar approaches have been taken previously for new construction to develop extremely energy efficient homes that are comfortable safe and durable, and often cost less than standard construction. This is best epitomized by the Building America program whose partners have built thousands of residences throughout the U.S. using these principles. The differences between retrofitting and new construction tend to limit the changes one can make to a building, so these packages rely on relatively simple and non-intrusive technologies and techniques. The retrofits also focus on changes to a building that will give many years of service to the occupants. Another key aspect of these best practices is that we need to know how a house is working so that we know what parts have the potential for improvement. To do this we have put together a set of diagnostic tools that combine physical measurements and checklists/questionnaires. The measured test results, observations and homeowner answers to questions are used to direct us towards the best retrofits applicable to each individual house. The retrofits will depend on the current condition of the building envelope and HVAC system, the local climate, the construction methods used for the house, and the presence of various energy saving systems (e.g., a Heat Recovery Ventilator) and/or materials. This is just like a doctor referring a patient for blood tests or x-rays before actually performing surgery. This way the doctor can be sure that he does the right thing. To take this analogy further - we can borrow from the medical profession and say that the first thought when retrofitting a house is to do no harm, i.e., do not make changes that could make the house worse to live in.

Report number: LBNL-54760	Year: 2004
Title: Improving Air Handler Efficiency in Houses	Published in: ACEEE Summer Study on Energy Efficiency in Buildings, Volume 1, Pages 341-352.
Authors: Walker, I.S.	Type: Conference Proceedings
Abstract: Although furnaces, air conditioners and heat pumps have become significantly more efficient over the last couple of decades, residential air handlers have typical efficiencies of only 10% to 15% due to poor electric motor performance and aerodynamically poor fans and fan housings. Substantial increases in performance could be obtained through improved air handler design and construction. A prototype residential air handler intended to address these issues has recently been developed. The prototype and a standard production fan were tested in a full-scale duct system and test chamber at LBNL specifically designed for testing heating, ventilation, and air conditioning systems. The laboratory tests compared efficiency, total airflow, sensitivity to duct system flow resistance, and the effects of installation in a smaller cabinet. The test results showed that the prototype air handler had about twice the efficiency of the standard air handler (averaged over a wide range of operating conditions) and was less sensitive to duct system flow resistance changes. The performance of both air handlers was significantly reduced by reducing the clearance between the air handler and cabinet it was placed in. These test results showed that in addition to the large scope for performance improvement, air handler fans need to be tested in the cabinets they operate in.

Report number: LBNL-54767	Year: 2004
Title: Duct Tape Durability Testing	Published in:
Authors: Sherman, M., Walker, I.S.	Type: Report
Abstract: Duct leakage has been identified as a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums or branches in the duct system. At each of these connections a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have typically shown that these seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory has been testing sealant durability for several years. Typical duct tape (i.e. fabric backed tapes with natural rubber adhesives) was found to fail more rapidly than all other duct sealants. This report summarizes the results of duct sealant durability testing of four UL 181B-FX listed duct tapes (two cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The tests involved the aging of common “core-to-collar joints” of flexible duct to sheet metal collars, and sheet metal “collar-to-plenum joints”. Periodic air leakage tests and visual inspection were used to document changes in sealant performance. The current study is a continuation of ongoing research at Lawrence Berkeley National Laboratory (Sherman and Walker, 2003; Walker and Sherman 2003; Walker and Sherman 2000; Sherman and Walker, 1998) that has the following objectives and outcomes:

Report number: LBNL-54696	Year: 2004
Title: A systems approach to retrofiting residential HVAC systems	Published in: 2004 ACEEE Summer Study on Energy Efficiency in Buildings, Volume 11, Pages 119-129.
Authors: McWilliams, J., Walker, I.S.	Type: Conference Proceedings
Abstract: A Best Practices Guide for retrofitting residential HVAC systems has recently been completed by DOE. The guide uses diagnostics and checklists to guide the user to specific retrofit packages that maximize retrofit energy savings, comfort and safety potential. The guide uses a systems approach to retrofitting where the interaction of different building components is considered throughout the retrofit selection process. For example, added building envelope insulation reduces building loads so that smaller capacity HVAC systems can be used. In this study, several houses were surveyed using the Best Practices Guide and a single house was selected for retrofitting. The objectives were to demonstrate how a successful system-wide retrofit can be carried out and to provide feedback to improve the guide. Because it represents a departure from current practice, a key aspect of this study was to investigate the interactions with contractors and code officials who are unfamiliar with the systems approach. The study found that the major barrier to the systems approach in retrofits was in changing the working practices of contractors and code officials.

Report number: LBNL-55011	Year: 2004
Title: Changing trends: A brief history of the U.S. household consumption of energy, water, food, beverages and tobacco	Published in: Proceedngs of the 2004 ACEEE Summer Study, Pacific Grove, CA, Volume 10, Pages 1-12.
Authors: Diamond, R., Moezzi, M.	Type: Conference Proceedings
Abstract: Can an historic analysis of consumption patterns of different commodities in the U.S. shed light on the consumption of energy? Can a review of past policies to reduce or change consumption patterns provide insight or guidance in developing new policies for reducing energy use? In order to better understand energy conservation policies, we take a brief look at the history in the US of consumption and curtailment of different commodities, including energy, raw materials, water, beverages and tobacco. Per capita consumption of all of these commodities has fluctuated over the past 100 years. With few exceptions, policies to reduce their consumption, e.g., prohibition, exhortation, regulation, taxation, have had little effect on consumption. Periods of curtailment, e.g., wartime, natural disasters and other shortages, have led to reductions in consumption, which were generally short lived. In some cases, reductions in consumption resulted in less service. In other cases, reduction in consumption led to changes in the services provided. By reviewing the history of consumption and curtailment we identify strategies that have the potential for promoting the long-term conservation of energy.

Report number: LBNL-48767	Year: 2003
Title: Guidelines for Residential Commissioning	Published in:
Authors: Wray, Craig, Walker, Iain, Sherman, Max.	Type: Report
Abstract: This guide is the culmination of a 30-month project that began in September 1999. The ultimate objective of the project is to increase the number of houses that undergo commissioning, which will improve the quality, comfort, and safety of homes for California citizens. The project goal is to lay the groundwork for a residential commissioning industry in California focused on end-use energy and non-energy issues. As such, we intend this guide to e a beginning and not an end. Our intent is that the guide will lead to the programmatic integration of commissioning with other building industry processes, which in turn will provide more value to a single site visit for people such as home energy auditors and raters, home inspectors, and building performance contractors.

Report number: LBNL 53484	Year: 2003
Title: Heat Recovery in Building Envelopes	Published in:
Authors: Walker, I.S., Sherman, M.H.	Type: Report
Abstract: Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Some studies have indicated that application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. The major objective of this study was to provide an improved prediction of the energy load due to infiltration by introducing a correction factor that multiplies the expression for the conventional load. This paper discusses simplified analytical modeling and CFD simulations that examine infiltration heat recovery (IHR) in an attempt to quantify the magnitude of this effect for typical building envelopes. For comparison, we will also briefly examine the results of some full-scale field measurements IHR based on infiltration rates and energy use in real buildings. The results of this work showed that for houses with insulated walls the heat recovery is negligible due to the small fraction of the envelope that participates in heat exchange with the infiltrating air. However; there is the potential for IHR to have a significant effect for higher participation dynamic walls/ceilings or uninsulated walls. This result implies that the existing methods for evaluating infiltration related building loads provide adequate results for typical buildings.

Report number: LBNL-53444	Year: 2003
Title: Case Study Field Evaluation of a Systems Approach to Retrofitting a Residential HVAC System	Published in:
Authors: Walker, I.S., McWilliams, J.A., Konopacki., S.J.	Type: Report
Abstract: This case study focusing on a residence in northern California was undertaken as a demonstration of the potential of a systems approach to HVAC retrofits. The systems approach means that other retrofits that can affect the HVAC system are also considered. For example, added building envelope insulation reduces building loads so that smaller capacity HVAC system can be used. Secondly, we wanted to examine the practical issues and interactions with contractors and code officials required to accomplish the systems approach because it represents a departure from current practice. We identified problems in the processes of communication and installation of the retrofit that led to compromises in the final energy efficiency of the HVAC system. These issues must be overcome in order for HVAC retrofits to deliver the increased performance that they promise. The experience gained in this case study was used to optimize best practices guidelines for contractors (Walker 2003) that include building diagnostics and checklists as tools to assist in ensuring the energy efficiency of "house as a system" HVAC retrofits. The best practices guidelines proved to be an excellent tool for evaluating the eight existing homes in this study, and we received positive feedback from many potential users who reviewed and used them. In addition, we were able to substantially improve the energy efficiency of the retrofitted case study house by adding envelope insulation, a more efficient furnace and air conditioner, an economizer and by reducing duct leakage.

Report number: LBNL-52216	Year: 2003
Title: Instrumented home energy rating and commissioning	Published in:
Authors: Sherman, M.H., Walker, I.S., Wray, C.P.	Type: Journal Article
Abstract: Currently, houses do not perform optimally or even as many codes and forecasts predict, largely because they are field assembled and there is no consistent process to identify deficiencies or to correct them. Solving this problem requires field performance evaluations using appropriate and agreed upon procedures in the form of a new process called residential commissioning. The purpose of this project is to develop and document these procedures and to demonstrate the value that applying them could provide in both new and existing California houses. This project has four specific objectives: to develop metrics and diagnostics for assessing house performance, to provide information on the potential benefits of commissioning using a whole-house approach, to develop programmatic guidelines for commissioning, and to conduct outreach efforts to transfer project results to industry stakeholders. The primary outcomes from this project are the development of residential commissioning guidelines and the analytical confirmation that there are significant potential benefits associated with commissioning California houses, particularly existing ones. In addition, we have made substantial advances in understanding the accuracy and usability of diagnostics for commissioning houses. In some cases, we have been able to work with equipment manufacturers to improve these aspects of their diagnostic tools. These outcomes provide a solid foundation on which to build a residential commissioning program in California. We expect that a concerted effort will be necessary to integrate such a program with existing building industry efforts and to demonstrate its use in the field.

Report number: LBNL-45959	Year: 2002
Title: Practical Diagnostics for Evaluating Residential Commissioning Metrics	Published in:
Authors: Wray, C.P., Walker, I.S., Siegel, J.A., Sherman, M.H.	Type: Report
Abstract: In this report, we describe what residential commissioning is, its characteristic elements, and how one might structure its process. Our intent in this discussion is to formulate and clarify these issues, but is largely preliminary because such a practice does not yet exist. Subsequent sections of the report describe metrics one can use in residential commissioning, along with the consolidated set of 24 practical diagnostics that the building industry can use now to evaluate them. Our discussion in the main body of this report is limited to existing diagnostics in areas of particular concern with significant interactions: envelope and HVAC systems. These areas include insulation quality, windows, airtightness, envelope moisture, fan and duct system airflows, duct leakage, cooling equipment charge, and combustion appliance backdrafting with spillage. Where possible, we also discuss the accuracy and usability of diagnostics, based on recent laboratory work and field studies by LBNL staff and others in more than 100 houses. These studies concentrate on evaluating diagnostics in the following four areas: the DeltaQ duct leakage test, air-handler airflow tests, supply and return grille airflow tests, and refrigerant charge tests. In addition, where possible, we identify the costs to purchase diagnostic equipment and the amount of time required to conduct the diagnostics.

Report number: LBNL-49697	Year: 2002
Title: Accuracy of flow hoods in residential applications	Published in: Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, California, Volume 1, Pages 339-350.
Authors: Wray, C.P., Walker, I.S. , Sherman, M.H.	Type: Conference Proceedings
Abstract: To assess whether houses can meet performance expectations, the new practice of residential commissioning will likely use flow hoods to measure supply and return grille airflows in HVAC systems. Depending on hood accuracy, these measurements can be used to determine if individual rooms receive adequate airflow for heating and cooling, to determine flow imbalances between different building spaces, to estimate total air handler flow and supply/return imbalances, and to assess duct air leakage. This paper discusses these flow hood applications and the accuracy requirements in each case. Laboratory tests of several residential flow hoods showed that these hoods can be inadequate to measure flows in residential systems. Potential errors are about 20% to 30% of measured flow, due to poor calibrations, sensitivity to grille flow non-uniformities, and flow changes from added flow resistance. Active flow hoods equipped with measurement devices that are insensitive to grille airflow patterns have an order of magnitude less error, and are more reliable and consistent in most cases. Our tests also show that current calibration procedures for flow hoods do not account for field application problems. As a result, a new standard for flow hood calibration needs to be developed, along with a new measurement standard to address field use of flow hoods. Lastly, field evaluation of a selection of flow hoods showed that it is possible to obtain reasonable results using some flow hoods if the field tests are carefully done, the grilles are appropriate, and grille location does not restrict flow hood placement.

Report number: LBNL-47476	Year: 2002
Title: An Evaluation of Superheat-Based Refrigerant Charge Diagnostics for Residential Cooling Systems	Published in: ASHRAE Transactions, Volume 108.
Authors: Siegel, J.A., Wray, C.P.	Type: Journal Article
Abstract: Although refrigerant charge has an important influence on the performance of residential cooling systems with fixed orifice metering devices, there has been little research to quantify the effects of incorrect charge or design new diagnostics for evaluating charge level. The most common diagnostic for charge level in these systems is the superheat test. In this paper, we examine three superheat technologies/techniques. Two of the diagnostics are appropriate for detecting incorrect charge; one is not. Additionally, measurements at four houses indicate that it is important to measure the condenser air entering temperature with a high degree of accuracy. Measurement of the wet bulb temperature in the return plenum and suction line temperature are equally important, but seemingly easier then measuring the condenser air temperature, as several measurement technologies yielded similar results for these quantities. The importance of refrigerant charge to energy use and capacity of residential cooling systems, the limitations of the superheat test, and the variations in the test method results and interfaces necessitate the development of a standard method or methods to determine refrigerant charge level.

Report number: LBNL-49757	Year: 2002
Title: Dirty air conditioners: Energy implications of coil fouling	Published in: Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA.
Authors: Siegel, J., Walker, I.S., Sherman, M.H.	Type: Conference Proceedings
Abstract: Residential air conditioning is responsible for a substantial amount of peak electrical demand and energy consumption throughout most of the United States. Coil fouling, the deposition of indoor dusts and other particulate matter on evaporator heat exchangers, increases system pressure drop and, correspondingly, decreases system air flow and air conditioner performance. In this paper, we apply experimental and simulation results describing particle deposition on evaporator coils as well as research about indoor particle and dust concentrations to determine coil fouling rates. The results suggest that typical coils foul enough to double evaporator pressure drop in 7 -- 11 years, much sooner than the expected 15 -- 30 year life time for an evaporator coil. The most important parameters in determining coil fouling times are the efficiency of the filter and indoor particle concentrations, although filter bypass and duct and coil design are important as well. The reduced air flows that result from coil fouling cause typical efficiency and capacity degradations of less than 5 %, however they can be much greater for marginal systems or extreme conditions. These energy issues, as well as possible indoor air quality issues resulting from fouling by biological aerosols, suggest that regular coil cleaning and the elimination of filter bypass should be an important part of residential air conditioning commissioning and maintenance practices.

Report number: LBNL-48258	Year: 2002
Title: Potential Benefits of Commissioning California Homes	Published in:
Authors: Matson, N.E., Wray, C.P., Walker, I.S., Sherman, M.H.	Type: Report
Abstract: No Abstract Available

Report number: LBNL-50184	Year: 2002
Title: What might U.S. homes and workplaces be like in the year 2020--and what are the implications for energy use?	Published in:
Authors: Diamond, Rick	Type: Report
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 the characterization of the physical environment, we also speculate as to the forces that would be influential in making these changes. Further reflection was made on the possible unintended consequences of these changes. The rationale for this exercise was to broaden the discussion on future energy use by looking at future scenarios in the context of everyday life.

Report number: LBNL-47412	Year: 2001
Title: Residential Commissioning to Assess Envelope and HVAC System Performance	Published in: Proceedings of the ASHRAE/DOE/BTECC Thermal Performance of Exterior Envelopes of Whole Buildings VIII, Clearwater Beach, FL.
Authors: Wray, C.P., Sherman, M.H.	Type: Conference Proceedings
Abstract: Residential commissioning is a new procedure to ensure that a house can perform optimally or at least meet basic safety, health, comfort, and energy intents. Many procedural elements, such as visual inspection and functional performance diagnostics, already exist in a fragmented environment. Most can be integrated into new industry guidelines for testing and tuning system performance in new and existing houses. This paper describes a consolidated set of practical diagnostics that can be used now to commission envelope and HVAC system performance. Where possible, we discuss the accuracy and usability of available diagnostics, based on recent laboratory work and field studies. We also describe areas in need of research and development, such as practical field diagnostics for envelope thermal conductance and combustion safety.

Report number: LBNL-44535	Year: 2000
Title: Residential Commissioning: A Review of Related Literature	Published in:
Authors: Wray, C.P., Piette, M.A., Sherman, M.H., Levinson, R.M., Matson, N.E., Driscoll, D.A., McWilliams, J.A.., Xu, T.T., Delp, W.W.	Type: Report
Abstract: The literature review reported here is the first step in a larger 30 month-long project that will lay the groundwork for a residential commissioning industry in California focused on end-use energy and non- energy issues. The intent of the review is to facilitate access to existing literature related to residential commissioning. Emphasis is placed on reviewing documents published over the past 20 years, which represents the period of time over which building commissioning and closely related issues have been actively reported. This report discusses the status of commercial building commissioning and compares it with residential commissioning. Based on an extensive review of 469 readily available documents, it summarizes existing metrics, diagnostics, and norms for all building types that are relevant for evaluating, tuning, and retrofitting various aspects of new and existing houses. The relevant areas of concern for California houses are: Building Envelope, Cooling Equipment and Heat Pumps, Air Distribution Systems, Indoor Air Quality, Combustion Appliances, Controls, and Other Electrical Appliances. There is a substantial amount of useful information in the literature about metrics, diagnostics, and norms that are relevant to residential commissioning. However, there are also some significant gaps. This report concludes by highlighting gaps in existing knowledge that require further research and development. Areas in particular need of work include: metrics, diagnostics, and norms for thermal mass and moisture-damage susceptibility; diagnostics for steady-state capacity and efficiency, as well as refrigerant charge level, for cooling equipment and heat pumps; diagnostics and norms for ventilation effectiveness and efficiency; diagnostics to evaluate the potential for backdrafting and combustion gas spillage; and metrics, diagnostics, and norms for controls and other electrical appliances.

Report number: LBNL-43638	Year: 2000
Title: Performance validation and energy analysis of HVAC systems using simulation	Published in: Energy & Buildings, Volume 32, Pages 5-17.
Authors: Salsbury, T.I., Diamond, R.C.	Type: Journal Article

Report number: LBNL-45862	Year: 2000
Title: Revealing myths about people, energy and buildings	Published in: Proceedings of the ACEEE 2000 Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 8, Pages 65-77.
Authors: Diamond, R.C., Moezzi, M.	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-43639	Year: 1999
Title: Automated Testing of HVAC Systems for Commissioning	Published in:
Authors: Salsbury, T.I., Diamond, R.C.	Type: Report

Report number: LBNL-40859	Year: 1998
Title: Residential Ventilation Systems	Published in:
Authors: Matson, N.E., Feustel, H.E.	Type: Report

Report number:	Year: 1997
Title: Long Term Monitoring of an EIFS Clad Wall	Published in: Journal of Thermal Insulation and Building Envelopes, Volume 20, Pages 320-338.
Authors: Said, N., Brown, W., Walker, I.	Type: Journal Article

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: LBNL-38320	Year: 1996
Title: Ventilation Control Strategies for Buildings with Hydronic Radiant Cooling in Hot Humid Climates	Published in: Proceedings of the RoomVent 1996, Yokohama, Japan, Pages 1.
Authors: Stetiu, C., Feustel, H.E., Nakano, Y.	Type: Conference Proceedings

Report number: LBL-38320	Year: 1996
Title: Phase Change Wallboard as an Alternative to Compressor Cooling in Residences?	Published in: Proceedings of the 1966 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 19, Pages 157-170.
Authors: Stetiu, C., Feustel, H.E.	Type: Conference Proceedings

Report number: LBL-35173	Year: 1995
Title: The Use of Blower-Door Data	Published in: Indoor Air, Volume 5, Pages 215-224.
Authors: Sherman, M.H.	Type: Journal Article

Report number: LBL-36933	Year: 1995
Title: Simplified Numerical Description of Latent Storage Characteristics for Phase Change Wallboard	Published in:
Authors: Feustel, H. W.	Type: Journal Article

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Report number: LBNL-59303	Year: 2007
Title: Sorption of organic gases in residential rooms	Published in: Atmospheric Environment, Volume 41, Pages 3251-3265.
Authors: Singer, B.C., Hodgson, A.T., Hotchi, T., Ming, K.Y., Sextro, R.G., Wood, E. E., Brown, N.J.	Type: Journal Article

Report number: LBNL-59363	Year: 2007
Title: Meta-Analyses of the Associations of Respiratory Health Effects with Dampness and Mold in Homes	Published in: Indoor Air, Volume 17, Pages 284-96.
Authors: Fisk, W.J., Lei-Gomez, Q., Mendell, M.M.	Type: Journal Article
Abstract: The Institute of Medicine (IOM) of the National Academy of Sciences recently completed a critical review of the scientific literature pertaining to the association of indoor dampness and mold contamination with adverse health effects. In this paper, we report the results of quantitative meta-analysis of the studies reviewed in the IOM report. We developed point estimates and confidence intervals (CIs) to summarize the association of several respiratory and asthma-related health outcomes with the presence of dampness and mold in homes. The odds ratios and confidence intervals from the original studies were transformed to the log scale and random effect models were applied to the log odds ratios and their variance. Models were constructed both accounting for the correlation between multiple results within the studies analyzed and ignoring such potential correlation. Central estimates of ORs for the health outcomes ranged from 1.32 to 2.10, with most central estimates between 1.3 and 1.8. Confidence intervals (95%) excluded unity except in two of 28 instances, and in most cases the lower bound of the CI exceeded 1.2. In general, the two meta-analysis methods produced similar estimates for ORs and CIs. Based on the results of the meta-analyses, building dampness and mold are associated with approximately 30% to 80% increases in a variety of respiratory and asthma-related health outcomes. The results of these meta-analyses reinforce the IOM's recommendation that actions be taken to prevent and reduce building dampness problems.

Report number: LBNL-63480	Year: 2007
Title: Evidence of acid-base interactions between amines and model indoor surfaces by ATR-FTIR spectroscopy	Published in: Atmospheric Environment, Volume 41, Pages 3177-3181.
Authors: Destaillats, H., Singer, B.C., Gundel, L A.	Type: Journal Article

Report number: LBNL-58785	Year: 2006
Title: Indoor Secondary Pollutants from Household Product Emissions in the Presence of Ozone: A Bench-Scale Chamber Study	Published in: Environmental Science and Technology, Volume 40, Pages 4421-4428.
Authors: Destaillats, H., Lunden, M., Singer, B.C., Coleman, B.K., Hodgson, A., Weschler, C.J., Nazaroff, W.	Type: Journal Article
Abstract: Ozone-driven chemistry is a major source of indoor secondary pollutants of health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and oxidation products were measured. Formaldehyde was a predominant oxidation byproduct for the three studied products, with yields under most conditions of 20-30% with respect to ozone consumed. Acetaldehyde, acetone, glycolaldehyde, formic acid and acetic acid were each also detected for two or three of the products. Immediately upon mixing of reactants, a scanning mobility particle sizer detected particle nucleation events that were followed by a significant degree of ultrafine particle growth. The production of secondary gaseous pollutants and particles depended primarily on the ozone level and was influenced by other parameters such as the air-exchange rate. Hydroxyl radical concentrations in the range 0.04-200 × 105 molecules cm-3 were measured. OH concentrations were observed to vary strongly with residual ozone level in the chamber, which was in the range 1 – 25 ppb, as is consistent with expectations from a simplified kinetic model. In a separate test, we exposed the dry residue of two products to ozone in the chamber and observed the formation of gas-phase and particle-phase secondary oxidation products.

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-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-51758	Year: 2003
Title: Reducing Indoor Residential Exposures to Outdoor Pollutants	Published in:
Authors: Sherman, Max H., Matson, Nance E.	Type: Journal Article
Abstract: Basic strategy for providing indoor air quality in residences is to dilute indoor sources with outdoor air. This strategy assumes that the outdoor air does not have pollutants at harmful levels or that the outdoor air is, at least, less polluted than the indoor air. When this is not the case, different strategies need to be employed to ensure adequate air quality in the indoor environment. These strategies include ventilation systems, filtration and other measures. These strategies can be used for several types of outdoor pollution, including smog, particulates and toxic air pollutants. This report reviews the impacts that typical outdoor air pollutants can have on the indoor environment and provides design and operational guidance for mitigating them. Poor quality air cannot be used for diluting indoor contaminants, but more generally it can become an indoor contaminant itself. This paper discusses strategies that use the building as protection against potentially hazardous outdoor pollutants, including widespread pollutants, accidental events, and potential attacks.

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-51328	Year: 2002
Title: Energy-related indoor environmental quality research: A priority agenda	Published in:
Authors: Fisk, W.J., Brager, G., Burge, H., Cummings, J., Levin, H., Loftness, V., Mendell, M.J., Persily, A., Taylor, S., Zhang, J.S.	Type: Report
Abstract: A multidisciplinary team of IEQ and energy researchers has defined a program of priority energy-related IEQ research. This paper describes the methods employed to develop the agenda, and 35 high priority research and development (R&D) project areas related to four broad goals: 1) identifying IEQ problems and opportunities; 2) developing and evaluating energy-efficient technologies for improving IEQ; 3) developing and evaluating energy-efficient practices for improving IEQ; and 4) encouraging or assisting the implementation of technologies or practices for improving IEQ. The identified R&D priorities reflect a strong need to benchmark IEQ conditions in small commercial buildings, schools, and residences. The R&D priorities also reflect the need to better understand how people are affected by IEQ conditions and by the related building characteristics and operation and maintenance practices. The associated research findings will provide a clearer definition of acceptable IEQ that is required to guide the development of technologies, practices, standards, and guidelines. Quantifying the effects of building characteristics and practices on IEQ conditions, in order to provide the basis for development of energy efficient and effective IEQ control measures, was also considered a priority. The development or advancement in a broad range of IEQ tools, technologies, and practices are also a major component of the priority research agenda. Consistent with the focus on "energy-related" research priorities, building ventilation and heating, ventilating and air conditioning (HVAC) systems and processes are very prominent in the agenda. Research related to moisture and microbiological problems, particularly within hot and humid climates, is also prominent within the agenda. The agenda tends to emphasize research on residences, small commercial buildings, and schools because these types of buildings have been underrepresented in prior research. Most of the research areas apply to both new construction and existing buildings. Nearly all of the recommended priority R&D project areas include tasks intended to facilitate the communication and implementation of the research results. In addition, the priority agenda includes several projects specifically designed to facilitate or stimulate the use of existing energy-efficient technologies and practices for improving IEQ. To assure that the research program continues to meet the needs of stakeholders and to facilitate the coordination of research among sponsors, the core team recommends an annual meeting attended by sponsors, a balanced group of stakeholders, and a selection of researchers implementing the agenda.

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:	Year: 2001
Title: Interior Moisture Design Loads for Residences	Published in: Proceedings of the ASHRAE/DOE/BTECC Thermal Performance of Exterior Envelopes of Whole Buildings VIII, Clearwater Beach, FL.
Authors: Tenwolde, A., Walker, I.S.	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-45044	Year: 1999
Title: Ozone-Surface Interactions: Investigations of Mechanisms, Kinetics, Mass Transport, and Implications for Indoor Air Quality	Published in:
Authors: Morrison, G.C.	Type: Report

Report number: LBNL-42047	Year: 1998
Title: Development of new VOC exposure metrics and their relationship to sick building syndrome symptoms	Published in: Indoor Air, Volume 8, Pages 140-152.
Authors: Ten Brinke, J., Selvin, S., Hodgson, A.T., Fisk, W.J.	Type: Journal Article

Report number: LBNL-43849	Year: 1998
Title: Indoor Air Quality Impacts of Ventilation Ducts: Ozone Removal and Emissions of Volatile Organic Compounds	Published in: Journal of Air and Waste Management Association, Volume 48, Pages 941-952.
Authors: Morrison, G.C., Nazaroff, W.W., Cano-Ruiz, A., Hodgson, A.T., Modera, M.P.	Type: Journal Article

Report number: LBL-38123	Year: 1996
Title: Pollutant Emission Factors from Residential Natural Gas Appliances: A Literature Review	Published in:
Authors: Traynor, G.W., Apte, M.G., Chang, G.	Type: Report

Report number: LBNL-37929	Year: 1996
Title: Measurement of Indoor Air Quality in Two New Test Houses	Published in:
Authors: Hodgson, A.T.	Type: Report

Report number:	Year: 1996
Title: Total exposure -- Indoor and outdoor air in residential and occupational settings	Published in: Proceedings of the 2nd Colloquium on Particulate Air Pollution and Human Health, Park City, UT.
Authors: Daisey, J., Lee, J.	Type: Conference Proceedings

Report number: LBL-35173	Year: 1995
Title: The Use of Blower-Door Data	Published in: Indoor Air, Volume 5, Pages 215-224.
Authors: Sherman, M.H.	Type: Journal Article

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Report number: LBNL-2021E	Year: 2009
Title: Air Distribution Effectiveness for Residential Mechanical Ventilation: Simulation and Comparison of Normalized Exposures	Published in:
Authors: Petithuguenin, T. D.P., Sherman, M.H.	Type: Report
Abstract: The purpose of ventilation is to dilute indoor contaminants that an occupant is exposed to. Even when providing the same nominal rate of outdoor air, different ventilation systems may distribute air in different ways, affecting occupants’ exposure to household contaminants. Exposure ultimately depends on the home being considered, on source disposition and strength, on occupants’ behavior, on the ventilation strategy, and on operation of forced air heating and cooling systems. In any multi-zone environment dilution rates and source strengths may be different in every zone and change in time, resulting in exposure being tied to occupancy patterns. This paper will report on simulations that compare ventilation systems by assessing their impact on exposure by examining common house geometries, contaminant generation profiles, and occupancy scenarios. These simulations take into account the unsteady, occupancy-tied aspect of ventilation such as bathroom and kitchen exhaust fans. As most US homes have central HVAC systems, the simulation results will be used to make appropriate recommendations and adjustments for distribution and mixing to residential ventilation standards such as ASHRAE Standard 62.2. This paper will report on work being done to model multizone airflow systems that are unsteady and elaborate the concept of distribution matrix. It will examine several metrics for evaluating the effect of air distribution on exposure to pollutants, based on previous work by Sherman et al. (2006).

Report number: LBNL 62700	Year: 2008
Title: Air Distribution Effectiveness for Different Mechanical Ventilation Systems	Published in: International Journal of Ventilation, Volume 6, Pages 307-314.
Authors: Sherman, M.H., Walker, I.S.	Type: Journal Article

Report number: LBNL-61282	Year: 2008
Title: Energy Impact of Residential Ventilation Standards in California	Published in: ASHRAE Journal, Volume 114, Pages 482-493.
Authors: Sherman, M.H., Walker, I.S.	Type: Journal Article
Abstract: The California Energy Commission is considering upgrading the State energy code, known as Title 24, to require mechanical ventilation based on the requirements of ASHRAE Standard 62.2-2004, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. These requirements will require mechanical ventilation systems to be installed in virtually all new homes, but allows for a wide variety of design solutions. These solutions, however, may have different energy costs and non-energy benefits. The authors have used a detailed simulation model to evaluate the energy impacts of common and proposed mechanical ventilation approaches for a variety of climates. These results separate the energy needed to ventilate from the energy needed to condition the ventilation air, from the energy needed to distribute and/or temper the ventilation air. The results show that exhaust systems are generally the most energy efficient method of meeting the proposed requirements, but that supply and balanced systems can provide additional non-energy benefits.

Report number: LBNL-1220E	Year: 2008
Title: Infiltration in ASHRAE’s Residential Ventilation Standards	Published in:
Authors: Sherman, M.H.	Type: Report
Abstract: The purpose of ventilation is to dilute or remove indoor contaminants that an occupant could be exposed to. It can be provided by mechanical or natural means. ASHRAE Standards including standards 62, 119, and 136 have all considered the contribution of infiltration in various ways, using methods and data from 20 years ago. The vast majority of homes in the United States and indeed the world are ventilated through natural means such as infiltration caused by air leakage. Newer homes in the western world are tight and require mechanical ventilation. As we seek to provide acceptable indoor air quality at minimum energy cost, it is important to neither over-ventilate nor under-ventilate. Thus, it becomes critically important to correctly evaluate the contribution infiltration makes to both energy consumption and equivalent ventilation. ASHRAE Standard 62.2 specifies how much mechanical ventilation is considered necessary to provide acceptable indoor air quality, but that standard is weak on how infiltration can contribute towards meeting the total requirement. In the past ASHRAE Standard 136 was used to do this, but new theoretical approaches and expanded weather data have made that standard out of date. This article will describe how to properly treat infiltration as an equivalent ventilation approach and then use new data and these new approaches to demonstrate how these calculations might be done both in general and to update Standard 136. �

Report number: LBNL-1031E	Year: 2008
Title: On The Valuation of Infiltration towards Meeting Residential Ventilation Needs	Published in:
Authors: Sherman, M.H.	Type: Report
Abstract: The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. It can be provided by mechanical or natural means. In most homes, especially existing homes, infiltration provides the dominant fraction of the ventilation. As we seek to provide acceptable indoor air quality at minimum energy cost, it is important to neither over-ventilate nor under-ventilate. Thus, it becomes critically important to correctly evaluate the contribution infiltration makes to both energy consumption and equivalent ventilation. ASHRAE Standards including standards 62, 119, and 136 have all considered the contribution of infiltration in various ways, using methods and data from 20 years ago.

Report number: LBNL-41E	Year: 2008
Title: Summary of Workshop: Barriers to Energy Efficient Residential Ventilation	Published in:
Authors: Sherman, M.H.	Type: Report

Report number: LBNL-376E	Year: 2008
Title: Effectiveness of Urban Shelter-in-Place III: Urban Districts	Published in: Building Simulation, Volume 1, Pages 144-157.
Authors: Chan, W.R., Nazaroff, W.W., Price, P.N., Gadgil, A.J.	Type: Journal Article

Report number: LBNL-62297	Year: 2007
Title: The Effects of Roof Reflectance on Air Temperatures Surrounding a Rooftop Condensing Unit	Published in: Energy and Buildings, Volume 40, Pages 11-28.
Authors: Wray, C.P., Akbari, H.A.	Type: Journal Article

Report number: LBNL-62297	Year: 2007
Title: The Effects of Roof Reflectance on Air Temperatures Surrounding a Rooftop Condensing Unit	Published in:
Authors: Wray, C.P., Akbari, H.A.	Type: Report

Report number: LBNL-62182	Year: 2007
Title: Humidity Implications for Meeting Residential Ventilation Requirements	Published in: Buildings X Conference - Thermal Performance of the Exterior Envelopes of Whole Buildings, Pages Air Tightness II–Practices III–A .
Authors: Walker, I.S., Sherman, M.H.	Type: Conference Proceedings
Abstract: In 2003 ASHRAE approved the nation’s first residential ventilation standard, ASHRAE Standard 62.2. Because meeting this standard can significantly change the ventilation rate in residences there is a concern about how these ventilation rate changes may impact humidity. This paper examines the effects of providing ASHRAE 62.2 levels of ventilation on humidity in residences that are typical of new construction (based on International Energy Conservation Code requirements). Four different systems were simulated in six climates of varying outdoor humidity characteristics (Charlotte, Houston, Kansas City, Seattle, Minneapolis and Phoenix). In order to capture moisture related HVAC system operation, such as the lack of dehumidification from typical air conditioning systems at the beginning of each cycle, we developed a simulation tool that operates on a minute-by-minute basis and utilizes a dynamic model of air conditioner performance. The simulations also include the effects of internal generation. Typical of most residences, the dehumidification in the houses is provided by the operation of cooling equipment that is controlled by temperature, rather than humidity. The results show that although 62.2 compliant ventilation systems increase average indoor humidity in hot humid climates, the number of high humidity events is unchanged. In less humid climates 62.2 compliant ventilation systems do not significantly affect the indoor humidity. Other factors such as occupant density, climate and air conditioner operation are more significant factors in determining indoor humidity.

Report number: LBNL-62341	Year: 2007
Title: Energy impact of residential ventilation norms in the United States	Published in:
Authors: Sherman, M.H., Walker, I.S.	Type: Report
Abstract: The first and only national norm for residential ventilation in the United States is Standard 62.2-2004 published by the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE). This standard does not by itself have the force of regulation, but is being considered for adoption by various jurisdictions within the U.S. as well as by various voluntary programs. The adoption of 62.2 would require mechanical ventilation systems to be installed in virtually all new homes, but allows for a wide variety of design solutions. These solutions, however, may have a different energy costs and non-energy benefits. This report uses a detailed simulation model to evaluate the energy impacts of currently popular and proposed mechanical ventilation approaches that are 62.2 compliant for a variety of climates. These results separate the energy needed to ventilate from the energy needed to condition the ventilation air, from the energy needed to distribute and/or temper the ventilation air. The results show that exhaust systems are generally the most energy efficient method of meeting the proposed requirements. Balanced and supply systems have more ventilation resulting in greater energy and their associated distribution energy use can be significant.

Report number: LBNL-62700	Year: 2007
Title: Air distribution effectiveness for different mechanical ventilation systems	Published in: 2nd PALENC Conference and 28th AIVC Conference on Building Low Energy Cooling and Advanced Ventilation Technologies in the 21st Century, Volume 2, Pages 964-968.
Authors: Sherman, M.H., Walker, I.S., M.Santamouris, P.Wouters	Type: Conference Proceedings
Abstract: The purpose of ventilation is to dilute indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix conditions between zones. Different types of ventilation systems will provide different amounts of dilution depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on work being done to both model the impact of different systems and measurements using a new multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The ultimate objective of this project is to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

Report number: LBNL-62078	Year: 2007
Title: Air Leakage of U.S. Homes: Model Prediction	Published in: Buildings X Conference - Thermal Performance of the Exterior Envelopes of Whole Buildings, Pages Air Tightness II-Practices III-A.
Authors: Sherman, M.H., McWilliams, J.A.	Type: Conference Proceedings
Abstract: Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses a model developed from that database in conjunction with US Census Bureau data for estimating air leakage as a function of location throughout the US.

Report number: LBNL-57730	Year: 2007
Title: Review of Residential Ventilation Technologies.	Published in: HVAC&R Research, Volume 13, Pages 325-348.
Authors: Russell, M.L., Sherman, M.H., Rudd, A.F.	Type: Journal Article
Abstract: This paper reviews current and potential ventilation technologies for residential buildings in North America and a few in Europe. The major technologies reviewed include a variety of mechanical systems, natural ventilation, and passive ventilation. Key parameters that are related to each system include operating costs, installation costs, ventilation rates, heat recovery potential. It also examines related issues such as infiltration, duct systems, filtration options, noise, and construction issues. This report describes a wide variety of systems currently on the market that can be used to meet ASHRAE Standard 62.2. While these systems generally fall into the categories of supply, exhaust or balanced, the specifics of each system are driven by concerns that extend beyond those in the standard and are discussed. Some of these systems go beyond the current standard by providing additional features (such as air distribution or pressurization control). The market will decide the immediate value of such features, but ASHRAE may wish to consider modifications to the standard in the future.

Report number: LBNL-62107	Year: 2007
Title: Effectiveness of urban shelter-in-place. II: Residential Districts	Published in: Atmospheric Environment, Volume 41, Pages 7082-7095.
Authors: Chan, W.R., Nazaroff, W.W., Price, P.N., Gadgil, A.J.	Type: Journal Article

Report number: LBNL-61686	Year: 2007
Title: Effectiveness of Urban Shelter-in-Place I: Idealized Conditions	Published in: Atmospheric Environment, Volume 41, Pages 4962-4976 .
Authors: Chan, W.R., Nazaroff, W.W., Price, P. N., Gadgil, A.J.	Type: Journal Article

Report number:	Year: 2006
Title: An Attic-Interior Infiltration and Interzone Transport Model of a House	Published in: Building and Environment, Volume 40, Pages 701-718.
Authors: Walker, I.S., Forest, T.W., Wilson, D.J.	Type: Journal Article

Report number: LBNL-59889	Year: 2006
Title: Ventilation requirements in hot, humid climates	Published in: 15th Symposium on Improving Building Systems in Hot Humid Climates, Volume Codes, ESL-HH-06/07-04.
Authors: Walker, I, S., Sherman, M.H.	Type: Conference Proceedings

Report number: LBNL-59998	Year: 2006
Title: Evaluation of existing technologies for meeting residential ventilation requirements.	Published in:
Authors: Walker, I, S., Sherman, M.	Type: Report

Report number: LBNL-59202	Year: 2006
Title: Air Tightness of US Homes: Model Development	Published in:
Authors: Sherman, M.	Type: Report
Abstract: Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses that database to develop a model for estimating air leakage as a function of climate, building age, floor area, building height, floor type, energy-efficiency and low-income designations. The model developed can be used to estimate the leakage distribution of populations of houses.

Report number: LBNL-59620	Year: 2006
Title: Ventilation Behavior and Household Characteristics in New California Houses	Published in:
Authors: Price, P. N., Sherman, M.H.	Type: Report
Abstract: A survey was conducted to determine occupant use of windows and mechanical ventilation devices; barriers that inhibit their use; satisfaction with indoor air quality (IAQ); and the relationship between these factors. A questionnaire was mailed to a stratified random sample of 4,972 single-family detached homes built in 2003, and 1,448 responses were received. A convenience sample of 230 houses known to have mechanical ventilation systems resulted in another 67 completed interviews. Results: - Many houses are under-ventilated: depending on season, only 10-50% of houses meet the standard recommendation of 0.35 air changes per hour. - Local exhaust fans are under-utilized. For instance, about 30% of households rarely or never use their bathroom fan. - More than 95% of households report that indoor air quality is "very" or "somewhat" acceptable," although about 1/3 of households also report dustiness, dry air, or stagnant or humid air. - Except households where people cook several hours per week, there is no evidence that households with significant indoor pollutant sources get more ventilation. - Except households containing asthmatics, there is no evidence that health issues motivate ventilation behavior. - Security and energy saving are the two main reasons people close windows or keep them closed.

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-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-59041	Year: 2006
Title: Development of a mathematical air leakage model from measured data	Published in:
Authors: Jung, M., McWilliams, J.	Type: Report
Abstract: A statistical model was developed to relate residential building shell leakage to building characteristics such as building height, floor area, floor leakage, duct leakage, and year built or the age of the house. Statistical regression techniques were used to determine which of the potential building characteristics best described the data. Seven preliminary regressions were performed to investigate the influence of each variable. The results of the eighth and last multivariable linear regression form the predictive model. The major factors that influence the tightness of a residential building are participation in an energy efficiency program (40% tighter than ordinary homes), having low-income occupants (145% leakier than ordinary) and the age of a house (1% increase in Normalized Leakage per year). This predictive model may be applied to data within the range of the data that was used to develop the model.

Report number: LBNL-58713	Year: 2005
Title: Report on Applicability of Residential Ventilation Standards in California	Published in:
Authors: Sherman, M.H., McWilliams, J.A.	Type: Report

Report number: LBNL-54496	Year: 2005
Title: Houses Need to Breathe…Right?	Published in:
Authors: Sherman, M.	Type: Report
Abstract: Sick Building Syndrome. Toxic mold. Asthma. The EPA lists poor indoor air quality (IAQ) as the fourth-largest environmental threat to our country. The American Lung Association notes a link between IAQ and Asthma-the most serious chronic illness of American children. Outdoor air can remove much of the moisture and other indoor contaminants that cause these problems. So tight houses are bad, right? Buildings need to breathe, don't they? Well, no. And yes. Tight houses are energy efficient, that's good. But without ventilation they're unhealthy and uncomfortable. And that's bad.

Report number: LBNL-57236	Year: 2005
Title: Review of Literature Related to Residential Ventilation Requirements	Published in:
Authors: McWilliams, J., Sherman, M.	Type: Report
Abstract: This paper reviews current ventilation codes and standards for residential buildings in Europe and North America. It also examines the literature related to these standards such as occupant surveys of attitudes and behavior related to ventilation, and research papers that form the technical basis of the ventilation requirements in the standards. The major findings from the literature are that ventilation is increasingly becoming recognized as an important component of a healthy dwelling, that the ventilation standards tend to cluster around common values for recommended ventilation rates, and that surveys of occupants showed that people generally think that ventilation is important, but that their understanding of the ventilation systems in their houses is low.

Report number: LBNL-53367	Year: 2005
Title: Analyzing a database of residential air leakage in the United States	Published in: Atmospheric Environment, Volume 39, Pages 3445-3455.
Authors: Chan, W.R., Nazaroff, W., Price, P. N., Sohn, M.D., Gadgil, A.	Type: Journal Article
Abstract: We analyzed more than 70,000 air leakage measurements in houses across the United States to relate leakage area—the effective size of all penetrations of the building shell—to readily available building characteristics such as building size, year built, geographic region, and various construction characteristics. After adjusting for the lackof statistical representativeness of the data, we found that the distribution of leakage area normalized by floor area is approximately lognormal. Based on a classification tree analysis, year built and floor area are the two most significant predictors of leakage area: older and smaller houses tend to have higher normalized leakage areas than newer and larger ones. Multivariate regressions of normalized leakage are presented with respect to these two factors for three house classifications: low-income households, energy program houses, and conventional houses. We demonstrate a method of applying the regression model to housing characteristics from the American Housing Survey to derive a leakage-area distribution for all single-family houses in the US. The air exchange rates implied by these estimates agree reasonably well with published measurements.

Report number: LBNL-49577	Year: 2004
Title: Fomaldehyde as a Basis for Residential Ventilation Rates	Published in: Indoor Air, Volume 14, Pages 2-9.
Authors: Sherman, M.H., Hodgson, A.T.	Type: Journal Article
Abstract: Traditionally, houses in the U.S. have been ventilated by passive infiltration in combination with active window opening. However in recent years, the construction quality of residential building envelopes has been improved to reduce infiltration, and the use of windows for ventilation also may have decreased due to a number of factors. Thus, there has been increased interest in engineered ventilation systems for residences. The amount of ventilation provided by an engineered system should be set to protect occupants from unhealthy or objectionable exposures to indoor pollutants, while minimizing energy costs for conditioning incoming air. Determining the correct ventilation rate is a complex task, as there are numerous pollutants of potential concern, each having poorly characterized emission rates, and poorly defined acceptable levels of exposure. One ubiquitous pollutant in residences is formaldehyde. The sources of formaldehyde in new houses are reasonably understood, and there is a large body of literature on human health effects. This report examines the use of formaldehyde as a means of determining ventilation rates and uses existing data on emission rates of formaldehyde in new houses to derive recommended levels. Based on current, widely accepted concentration guidelines for formaldehyde, the minimum and guideline ventilation rates for most new houses are 0.28 and 0.5 air changes per hour, respectively.

Report number: LBNL-54331	Year: 2004
Title: ASHRAE's first residential ventilation standard	Published in: Buildings IX Conference, SP-95.
Authors: Sherman, M.H.	Type: Conference Proceedings
Abstract: Abstract: ASHRAE has recently published its first residential ventilation standard, Standard 62.2-2003. This standard defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable indoor air quality in low-rise residential buildings. The standard includes a minimum whole-house ventilation rate, local exhaust rates and other kinds of source control. This report summarizes the standard and indicates the key issues. Providing acceptable indoor air quality often depends more on source control than on ventilaton itself. Much source control depends on the interactions between ventilation and the building envelope. Unbalanced ventilation systems combined with a tight envelope can lead to building pressurization or depressurization. These building pressures can mitigate or enhance heat and mass transport through the building envelope, which can impact both energy use and moisture performance. These pressures can also impair systems and components not directly tied to ventilation, such as the operation of combustion appliances or entrainment of soil gas. Such "house-as-system" issues were important considerations in the development of the standard and will be discussed in the report. ASHRAE is continuing to develop and enhance these efforts by using a continuous maintenance process for the standard and by creation of a companion guideline to reflect the state of the art.

Report number: LBNL-53776	Year: 2004
Title: ASHRAE's New Residential Ventilation Standard	Published in: ASHRAE Journal, Volume 46, Pages 149-156.
Authors: Sherman, Max H.	Type: Journal Article
Abstract: ASHRAE, the American Society of Heating, Refrigerating, and Air-conditioning Engineers, is the world leader in the field of heating, ventilating, air-conditioning and refrigeration (HVAC&R). ASHRAE has recently released a new residential ventilation standard reflecting minimum requirements for homes. They have also released a top ten list of things that homeowners should be aware of to protect their indoor environment. This article provides a summary of what homeowners and HVAC&R professionals should know regarding residential ventilation.

Report number: LBNL-55107	Year: 2004
Title: Why We Ventilate Our Houses – An Historical Look	Published in: 2004 ACEEE Summer Study on Energy Efficiency in Buildings, Volume 7, Pages 241-250.
Authors: Matson, N., Sherman, M.	Type: Conference Proceedings
Abstract: The knowledge of how to ventilate buildings, and how much ventilation is necessary for human health and comfort, has evolved over centuries of trial and error. Humans and animals have developed successful solutions to the problems of regulating temperature and removing air pollutants through the use of ventilation. These solutions include ingenious construction methods, such as engineered passive ventilation (termite mounds and passive stacks), mechanical means (wing-powered, fans), and an evolving effort to identify problems and develop solutions. Ventilation can do more than help prevent building occupants from getting sick; it can provide an improved indoor environment. Codes and standards provide minimum legal requirements for ventilation, but the need for ventilation goes beyond code minima. In this paper we will look at indoor air pollutant sources over time, the evolution of ventilation strategies, current residential ventilation codes and standards (e.g., recently approved ASHRAE Standard 62.2), and briefly discuss ways in which we can go beyond the standards to optimize residential ventilation, reduce indoor air quality problems, and provide corresponding social and economic benefit.

Report number: LBNL 53484	Year: 2003
Title: Heat Recovery in Building Envelopes	Published in:
Authors: Walker, I.S., Sherman, M.H.	Type: Report
Abstract: Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Some studies have indicated that application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. The major objective of this study was to provide an improved prediction of the energy load due to infiltration by introducing a correction factor that multiplies the expression for the conventional load. This paper discusses simplified analytical modeling and CFD simulations that examine infiltration heat recovery (IHR) in an attempt to quantify the magnitude of this effect for typical building envelopes. For comparison, we will also briefly examine the results of some full-scale field measurements IHR based on infiltration rates and energy use in real buildings. The results of this work showed that for houses with insulated walls the heat recovery is negligible due to the small fraction of the envelope that participates in heat exchange with the infiltrating air. However; there is the potential for IHR to have a significant effect for higher participation dynamic walls/ceilings or uninsulated walls. This result implies that the existing methods for evaluating infiltration related building loads provide adequate results for typical buildings.

Report number: LBNL-53811	Year: 2003
Title: Ventilation Technologies Scoping Study	Published in:
Authors: Walker, Iain S., Sherman, Max H.	Type: Report
Abstract: This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the needs of California, determining residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and level of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

Report number: LBNL-53356	Year: 2003
Title: Building Airtightness: Research and Practice	Published in: State of the Art in Ventilation, Pages 8-12.
Authors: Sherman, Max H., Chan, Wanyu R.	Type: Book Section
Abstract: This report summarizes the state of the art on building air tightness by reviewing the current and recent literature on both research and practice. The focus of this report is on techniques to measure the tightness of the building envelope and on what has been learned by doing so. This report reviews over 100 of the most important publications relating to the topic. The report covered the fundamentals of air leakage including the hydrodynamics of leaks, which has led to all of the measurement techniques currently in use. The measurement techniques reviewed focus on the fan pressurization technique and its derivates, but the report covers novel techniques as well. Air tightness metrics allow data to be shared and compared and the basic air tightness metrics are reviewed and discussed as well as a brief discussion on norms and normalization. The bulk of the report discusses data which has been taken over the last twenty years and what it can tell us about buildings of different types, locations and properties.

Report number: LBNL-49747	Year: 2003
Title: Review of air flow measurement techniques	Published in:
Authors: McWilliams, Jennifer	Type: Report
Abstract: Airflow measurement techniques are necessary to determine the most basic of indoor air quality questions: "Is there enough fresh air to provide a healthy environment for the occupants of the building?" This paper outlines airflow measurement techniques, but it does not make recommendations for techniques that should be used. The airflows that will be discussed are those within a room or zone, those between rooms or zones, such as through doorways (open or closed) or passive vents, those between the building and outdoors, and those through mechanical air distribution systems. Techniques that are highlighted include particle streak velocimetry, hot wire anemometry, fan pressurization (measuring flow at a given pressure), tracer gas, acoustic methods for leak size determination, the Delta Q test to determine duct leakage flows, and flow hood measurements. Because tracer gas techniques are widely used to measure airflow, this topic is broken down into sections as follows: decay, pulse injection, constant injection, constant concentration, passive sampling, and single and multiple gas measurements for multiple zones. Selected papers are annotated, and a bibliography is included for each topic with full abstracts.

Report number: LBNL-53367	Year: 2003
Title: Analysis of U.S. Residential Air Leakage Database	Published in:
Authors: Chan, W.R., Price, P. N., Sohn, M.D., Gadgil, A.J.	Type: Report
Abstract: The air leakage of a building envelope can be determined from fan pressurization measurements with a blower door. More than 70,000 air leakage measurements have been compiled into a database. In addition to air leakage, the database includes other important characteristics of the dwellings tested, such as floor area, year built, and location. There are also data for some houses on the presence of heating ducts, and floor/basement construction type. The purpose of this work is to identify house characteristics that can be used to predict air leakage. We found that the distribution of leakage normalized with floor area of the house is roughly lognormal. Year built and floor area are the two most significant factors to consider when predicting air leakage: older and smaller houses tend to have higher normalized leakage areas compared to newer and larger ones. Results from multiple linear regression of normalized leakage with respect to these two factors are presented for three types of houses: low-income, energy-efficient, and conventional. We demonstrate a method of using the regression model in conjunction with housing characteristics published by the US Census Bureau to derive a distribution that describes the air leakage of the single-family detached housing stock. Comparison of our estimates with published datasets of air exchange rates suggests that the regression model generates accurate estimates of air leakage distribution.

Report number: LBNL-43254	Year: 2002
Title: Suite Ventilation Characteristics of Current Canadian Mid-and High-Rise Residential Buildings	Published in: ASHRAE Transactions, Volume 110 (Part 2).
Authors: Wray, Craig P.	Type: Journal Article
Abstract: This paper characterizes ventilation in residential suites located in ten buildings in major metropolitan areas of Canada. All buildings were between six and thirty-two stories tall and were built between 1990 and 1995. 1. The key findings from field performance tests of these buildings were: 2. Corridor supply airflows usually did not meet design flows. 3. Makeup air paths for suite exhaust were not properly designed. 4. Suite access door leakage was highly variable and usually did not meet smoke control requirements. 5. Airflow from the corridor through the suite access door leakage appeared to be the primary ventilation air supply for suites. 6. Suites were usually well-ventilated, but some were marginally- or under-ventilated. 7. Poor pressure control often allowed transfer air from one suite to another. Inter-suite transfer air fractions ranged from 0 to 45%, with an average of 19%. In summary, this work showed suite ventilation can be highly influenced by corridor supply flows, by the treatment of corridor access doors, and by transfer airflows. As a result, suite ventilation at any given time in current mid- and high-rise residential buildings is very difficult to predict. To ensure suite ventilation performs as intended under all operating conditions, the building industry needs to address the identified problems through improved ventilation design, operation, and maintenance practices.

Report number:	Year: 2002
Title: Ventilation System Design of Recent Canadian Multi-Unit Residential Buildings	Published in: ASHRAE Transactions, Volume 106.
Authors: Theaker, I.G., Wray, C.P.	Type: Journal Article
Abstract: No Abstract available.

Report number: LBNL-48671	Year: 2002
Title: Air Tightness of New U.S. Houses: A Preliminary Report	Published in:
Authors: Sherman, M.H., Matson, N.E.	Type: Report
Abstract: Most dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems. Consequently, quantification of envelope air-tightness is critical to determining how much energy is being lost through infiltration and how much infiltration is contributing toward ventilation requirements. Envelope air tightness and air leakage can be determined from fan pressurization measurements with a blower door. Tens of thousands of unique fan pressurization measurements have been made of U.S. dwellings over the past decades. LBNL has collected the available data on residential infiltration into its Residential Diagnostics Database, with support from the U.S. Department of Energy. This report documents the envelope air leakage section of the LBNL database, with particular emphasis on new construction. The work reported here is an update of similar efforts carried out a decade ago, which used available data largely focused on the housing stock, rather than on new construction. The current effort emphasizes shell tightness measurements made on houses soon after they are built. These newer data come from over two dozen datasets, including over 73,000 measurements spread throughout a majority of the U.S. Roughly one-third of the measurements are for houses identified as energy-efficient through participation in a government or utility program. As a result, the characteristics reported here provide a quantitative estimate of the impact that energy-efficiency programs have on envelope tightness in the US, as well as on trends in construction.

Report number: LBNL-51324	Year: 2002
Title: Infiltration heat recovery in building walls: Computational fluid dynamics investigations results	Published in:
Authors: Abadie, M.O., Finlayson, E.O., Gadgil, A. J.	Type: Report
Abstract: Conventional calculations of heating (and cooling) loads for buildings assume that conduction heat loss (or gain) through walls is independent of air infiltration heat loss (or gain). During passage through the building envelope, infiltrating air substantially exchanges heat wall insulation leading to partial recovery of heat conducted through the wall. The Infiltration Heat Recovery (IHR) factor was introduced to quantify the heat recovery and correct the conventional calculations. In this study, Computational Fluid Dynamics was to calculate infiltration heat recovery under a range of idealized conditions, specifically to understand factors that influence it, and assess its significance in building heat load calculations. This study shows for the first time the important effect of the external boundary layers on conduction and infiltration heat loads. Results show (under the idealized conditions studied here) that (1) the interior details of the wall encountered in the leakage path (i.e., insulated or empty walls) do not greatly influence the IHR, the overall relative location of the cracks (i.e., inlet and outlet locations on the wall) has the largest influence on the IHR magnitude, (2) external boundary layers on the walls substantially contribute to IHR and (3) the relative error in heat load calculations resulting from the use of the conventional calculational method (i.e., ignoring IHR) is between 3% and 13% for infiltrating flows typically found in residential buildings.

Report number: LBNL-47329	Year: 2001
Title: Heat Recovery in Building Envelopes	Published in: Proceedings of the ASHRAE/DOE/BTECC Thermal Performance of Exterior Envelopes of Buildings VIII, Clearwater Beach, FL.
Authors: Sherman, M.H., Walker, I.S.	Type: Conference Proceedings

Report number: LBNL-44479	Year: 2000
Title: Selecting Whole-House Ventilation Strategies to Meet Proposed ASHRAE 62.2: Energy Cost Considerations	Published in: ASHRAE Transactions, Volume 106, Pages 681-691.
Authors: Wray, C.P., Matson, N.E., Sherman, M.H.	Type: Journal Article
Abstract: ASHRAE Standard 62.2P is being proposed to address residential ventilation issues. As housing, especially new housing, gets more airtight and better insulated, it has become clear that many homes are under-ventilated. The Standard contains requirements that provide minimum ventilation rates and source control measures necessary for acceptable indoor air quality. This paper uses previously reported analytical techniques to compare the energy costs of various ventilation strategies for a wide variety of climates and housing types. For new construction, we conclude that mechanical ventilation is needed. In new houses with gas heating, the cheapest whole-house system is a central exhaust fan. The marginal energy costs to provide such ventilation are on the order of 50¢ per day. However, other systems can be more appropriate when depressurization, filtration, moisture, and more expensive heating fuels are considered. For most of the existing housing stock, we conclude that infiltration provides adequate ventilation.

Report number: LBNL-44294	Year: 2000
Title: A Mathematical Model for Infiltration Heat Recovery	Published in:
Authors: Buchanan, C.R., Sherman, M.H.	Type: Report

Report number: LBNL- 42127	Year: 1999
Title: Distribution System Leakage Impacts on Apartment Building Ventilation Rates	Published in: ASHRAE Transactions, Volume 105, Pages 943-950.
Authors: Walker, I.S.	Type: Journal Article
Abstract: Forced air distribution systems in residential buildings are often located outside conditioned space, for example in attics, crawlspaces, garages and basements. Leaks from the ducts to these unconditioned spaces or outside can change flows through the registers and change the ventilation rates of the conditioned spaces. In this study, duct leakage flows were measured in several low-rise apartment buildings. The leakage flow measurements and other data about the apartments were used to develop a prototype apartment building. The multizone airflow model COMIS was then used on this prototype building to determine internal flows within the building, air flows through the building envelope and the impacts of the duct leakage on the ventilation rates. The effects of sealing the duct leaks were also examined in order to determine changes in infiltration rates resulting from duct retrofits. The simulation results showed that for the prototype tested here, the excess return leakage tended to decrease envelope infiltration flows by about 20% but the total infiltration load including return duct leaks more than doubled during system operation.

Report number: LBNL-42975	Year: 1999
Title: ASHRAE's Residential Ventilation Standard: Exigesis of Proposed Standard 62.2	Published in: ASHRAE Journal.
Authors: Sherman, M.	Type: Journal Article

Report number: LBNL-43641	Year: 1999
Title: A Guide to Energy Efficient Ventilation in Apartment Buildings, US Department of Energy (DOE/EE-0196)	Published in:
Authors: Diamond, R.C., Feustel, H.E., Matson, N.	Type: Report

Report number:	Year: 1998
Title: Field Testing to Characterize Suite Ventilation in Recently Constructed Mid- and High-Rise Residential Buildings	Published in:
Authors: Wray, C.P., Theaker, I.G., Moffatt, P.	Type: Report

Report number: LBNL-41447	Year: 1998
Title: A Comparison of the Power Law to Quadratic Formulations for Air Infiltration Calculations	Published in: Energy and Buildings, Volume 27, Pages 293-299.
Authors: Walker, I.S., Wilson, D.J., Sherman, M.H.	Type: Journal Article
Abstract: Although the power law has been broadly accepted in measurement and air infiltration standards, and in many air infiltration calculation methods, the assumption that the power law is true over the range of pressures that a building envelope experiences has not been well documented. In this paper, we examine the validity of the power law through theoretical analysis, laboratory measurements of crack flow and detailed field tests of building envelopes. The results of the theoretical considerations, and field and laboratory measurements indicate that the power law is valid for low pressure building envelope leakage.

Report number: LBNL-42361	Year: 1998
Title: Field Validation of Algebraic Equations for Stack and Wind Driven Air Infiltration Calculations	Published in: HVAC&R Research, Volume 4, Pages 119-139.
Authors: Walker, I.S., Wilson, D.J.	Type: Journal Article
Abstract: Explicit algebraic equations for calculation of wind and stack driven ventilation were developed by parametrically matching exact solutions to the flow equations for building envelopes. These separate wind and stack effect flow calculation procedures were incorporated in a simple natural ventilation model, AIM- 2, with empirical functions for superposition of wind and stack effect and for estimating wind shelter. The major improvements over previous simplified ventilation calculations are: a power law pressure-flow relationship is used to develop the flow equations form first principles, the furnace or fireplace flue is included as a separate leakage site and the model differentiates between houses with basements (or slab-on- grade) and crawlspaces. Over 3400 hours of measured ventilation rates from the test houses at the Alberta Home Heating Research Facility were used to validate the predictions of ventilation rates and to compare the AIM-2 predictions to those of other ventilation models. The AIM-2 model had bias and scatter errors of less than 15% for wind-dominated ventilation, and less than 7% for buoyancy ("stack-effect") dominated cases.

Report number:	Year: 1998
Title: Air Tightness of U.S. Dwellings	Published in: ASHRAE Transactions, Volume 104, Pages 1359-1367.
Authors: Sherman, M.H, Dickerhoff, D.J.	Type: Journal Article

Report number: LBNL-43642	Year: 1998
Title: Ventilation in Highrise Apartments	Published in: Proceedings of the Room Vent 1998 Conference, Stockholm, Sweden.
Authors: Feustel, H.E, Diamond, R.C.	Type: Conference Proceedings

Report number: LBNL-42098	Year: 1998
Title: CFD Simulation of Infiltration Heat Recovery	Published in: Proceedings of the 19th AIVC Conference, Oslo, Norway.
Authors: Buchanan, C.R., Sherman, M.H.	Type: Conference Proceedings

Report number: LBL-33854	Year: 1998
Title: LBL Meteorological Database for the United States	Published in:
Authors: Apte, M.G., Nero, A.V., Revzan, K.L.	Type: Report

Report number: LBNL-40423	Year: 1997
Title: New Generation of Sofware: Modeling of Energy Demands for Residential Ventilation with HTML Interface	Published in:
Authors: Forowicz, T.	Type: Report

Report number:	Year: 1996
Title: A Wind Shadow Model for Air Infiltration Sheltering by Upwind Obstacles	Published in: ASHRAE HVAC&R Research Journal, Volume 2, Pages 265-283.
Authors: Walker, I.S., Wilson, D.J., Forest, T.W.	Type: Journal Article
Abstract: The wind shadow model has been developed to calculate the wind sheltering effects of upwind obstacles for air infiltration calculations. This effect must be determined for infiltration calculations because, in almost all situations, only the unobstructed mean wind speed is known for a building site. This model has adapted the theoretical calculation procedures developed for far wake centreline velocity deficit calculations to near field flows, where shelter has a significant effect. The model uses the concept of a wind shadow projected downstream by upwind buildings to determine the effect of wake velocity reduction on building surfaces. The turbulent nature of the wake is accounted for by "flapping" the wake over a range of wind directions. The effectiveness of this model in accounting for sheltering effects in infiltration calculations has been examined by comparing infiltration model predictions including the wind shadow model to measured data from a row of test houses. The measured data covered a wide range of wind speeds, wind directions and leakage distributions by using over five thousand hours of infiltration measurements from five houses.

Report number: LBNL-39036	Year: 1996
Title: Residential Ventilation and Energy Characteristics	Published in:
Authors: Sherman, M., Matson, N.	Type: Report

Report number: LBL-38103	Year: 1996
Title: Diagnostics and measurements of infiltration and ventilation systems in high-rise apartment buildings	Published in: Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 1, Pages 95-101.
Authors: Feustel, H.E., Diamond, R.C.	Type: Conference Proceedings

Report number: LBNL-38103	Year: 1996
Title: Ventilation and Infiltration in Highrise Apartment Buildings	Published in:
Authors: Diamond, R.C., Feustel, H.E., Dickerhoff, D.J.	Type: Report

Report number: LBL-36879	Year: 1995
Title: A Simple Calculation Method for Attic Ventilation Rates	Published in: Proceedings of the 16th AIVC Conference, Volume 1, Pages 221-232.
Authors: Walker, I.S., Forest, T.W., Wilson, D.J.	Type: Conference Proceedings
Abstract: The ventilation of an attic is critical in estimating heating and cooling loads for buildings because the air temperature in the attic is highly sensitive to ventilation rate. In addition, attic ventilation is an important parameter for determining moisture accumulation in attic spaces that can lead to structural damage and reduced insulation effectiveness. Historically, attic venting has been a common method for controlling attic temperature and moisture, but there have been no calculation techniques available to determine attic ventilation rates. Current practice is to use rules of thumb for estimating attic vent areas. Simple algebraic relationships are developed here, using functions fitted to an exact numerical solution for air flow through attic envelopes. This algebraic model (AVENT) was developed to be easy to use as diagnostic or design tool. Key factors included in the model are: climate (wind and stack effect), wind shelter, leakage distribution and total attic leakage. This paper validates the model predictions by comparing to measured data from two attics at the Alberta Home Heating Research Facility (AHHRF). Average errors for the model are about 15% compared to the measured ventilation rates.

Report number:	Year: 1995
Title: Field Measurements of Ventilation Rates in Attics	Published in: Building and Environment, Volume 30, Pages 333-347.
Authors: Walker, I.S., Forest, T.W.	Type: Journal Article
Abstract: Field tests were carried out in two flat ceiling, residential attics at a dedicated test site over a two year period. The scope of this paper is to present measurements of ventilation rates, indoor-attic exchange rates, temperatures and wood moisture contents at various locations in the attics. Attic ventilation rates are correlated with wind speed, wind direction, and attic-outdoor temperature difference. Wind speed is shown to be the dominant driving force for ventilation; however, wind direction is important particularly when the attic is sheltered.

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Report number: LBNL-59256	Year: 2008
Title: Radon Progeny as a potential experimental tool for dosimetry of nanoaerosols	Published in: Submitted to Inhalation Toxicology.
Authors: Ruzer, L.S., Apte, M.G.	Type: Journal Article

Report number: LBNL-50041	Year: 2002
Title: Long Term Performance of Radon mitigation systems	Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 2, Pages 641-646.
Authors: Prill, R., Fisk, W.J.	Type: Conference Proceedings
Abstract: Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985 -- 1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes.

Report number:	Year: 2000
Title: Health risks due to radon in drinking water	Published in: Environmental Science & Technology, Volume 34, Pages 921-926.
Authors: Hopke, P.K., Borak, T.B., Doull, J., Cleaver, J.E., Eckerman, K.F., Gundersen, L.C., Harley, N.H., Hess, C.E., Kinner, N.E., Kopecky, K.J., McKone, T.E., Sextro, R.G., Simon, L.G.	Type: Journal Article

Report number: LBNL-43652	Year: 1999
Title: Effects of variable wind speed and direction on radon transport from soil into buildings: model development and exploratory results	Published in: Atmospheric Environment, Volume 33, Pages 2157-2168.
Authors: Riley, W.J., Robinson, A.L., Gadgil, A., Nazaroff, W.	Type: Journal Article
Abstract: We describe a novel modeling technique, based on Duhamel's theorem, to study the effects of time-varying winds on radon transport in soil near buildings. The technique, implemented in the model RapidSTART, reduces computational times for transient, three-dimensional, wind-induced soil-gas and radon transport by three to four orders of magnitude compared with conventional finite-di�erence models. To test model performance, we compared its predictions to analytical solutions of one-dimensional soil-column flow, finite-difference simulations of flow around a full-scale house, and measurements of transient soil-gas and radon entry into an experimental basement structure. These comparisons demonstrate that RapidSTART accurately simulates time-dependent radon transport through soil and its entry into buildings. As demonstrated in a previous study, steady winds can significantly affect radon entry. In this paper, we extend the findings of that study by applying RapidSTART to explore the impacts of fluctuating wind speed and direction on radon entry into a prototypical house. In soils with moderate to high permeability, wind fluctuations have a small to moderate effect on the soil-gas radon concentration field and entry rate into the building. Fluctuating wind direction dominates the impact on radon entry rates, while fluctuating wind speed has little effect. For example, in a soil with a permeability of 10~10m2, diurnal oscillations in wind direction can increase the predicted radon entry rate by up to 30% compared to steady-state predictions. ( 1999 Elsevier Science Ltd. All rights reserved.

Report number: LBNL-44040	Year: 1999
Title: Radon entry into houses: The importance of scale-dependent permeability	Published in: Health Physics, Volume 77, Pages 83-191.
Authors: Garbesi, K., A.L. Robinson, R.G. Sextro, W.W. Nazaroff	Type: Journal Article

Report number: LBNL-38961	Year: 1999
Title: Predicting Indoor Radon Concentrations in New Hampshire from Geologic Information and Other Covariates	Published in: Environmental Geology, Volume 37, Pages 181-194.
Authors: Apte, M.G., Price, P.N., Nero, A.V., Revzan, K.L.	Type: Journal Article

Report number:	Year: 1997
Title: Measurement of Radon Decay Products in Air by Alpha- and Beta-Spectrometry	Published in: Radiation Protection Dosimetry, Volume 72, Pages 43-48.
Authors: Ruzer, L.S., Sextro, R.G.	Type: Journal Article

Report number:	Year: 1997
Title: Soil-Gas Entry Into Houses Driven By Atmospheric Pressure Fluctuations -- the Influence of Soil Properties	Published in: Atmospheric Environment, Volume 31, Pages 1487-1495.
Authors: Robinson, A.L., Sextro, R.G., Riley, W.J.	Type: Journal Article

Report number:	Year: 1997
Title: Radon Entry into Buildings Driven by Atmospheric Pressure Fluctuations	Published in: Environmental Science & Technology, Volume 31, Pages 1742-1748.
Authors: Robinson, A.L., Sextro, R.G.	Type: Journal Article

Report number:	Year: 1997
Title: Predictions and Maps of County Mean Indoor Radon Concentrations in the Mid-Atlantic States	Published in: Health Physics, Volume 72, Pages 893-906.
Authors: Price, P.N.	Type: Journal Article

Report number:	Year: 1996
Title: Soil gas entry into an experimental basement driven by atmospheric pressure fluctuations, measurements, spectral analysis, and model comparison	Published in: Atmospheric Environment, Volume 31, Pages 1477-1485.
Authors: Robinson, A.L., Sextro, R.G., Fisk, W.J.	Type: Journal Article

Report number: LBL-36372	Year: 1996
Title: The Effect of Steady Winds on Radon Entry into Houses	Published in: Atmospheric Environment, Volume 30, Pages 1167-1176.
Authors: Riley, W.J., Gadgil, A.J., Bonnefous, Y.C., Nazaroff, W.W.	Type: Journal Article

Report number: LBL-36368	Year: 1996
Title: Regional and National Estimates of the Potential Energy Use, Energy Cost, and CO2 Emissions Associated with Radon Mitigation by Sub-Slab Depressurization	Published in: Energy and Buildings, Volume 24, Pages 203-212.
Authors: Riley, W.J., Fisk, W.J., Gadgil, A.J.	Type: Journal Article

Report number: LBL-37276	Year: 1996
Title: Joint Analysis of Long- and Short-Term Radon Monitoring Data from the Northern U.S	Published in: Environmental International, Volume 22, Pages 669-714.
Authors: Price, P.N., Nero, A.V.	Type: Journal Article

Report number: LBL-35369	Year: 1996
Title: Scale Dependence of Soil Permeability to Air: Measurement Method and Field Investigation	Published in: Water Resource Research, Volume 32, Pages 547-560.
Authors: Garbesi, K., Sextro, R.G., Robinson, A.L., Wooley, J.D., Owens, J.A., Nazaroff, W.W.	Type: Journal Article

Report number: LBL-36743	Year: 1995
Title: Direct measurements of soil-gas entry into an experimental basement driven by atmospheric pressure fluctuations	Published in: Geophysical Research Letters, Volume 22, Pages 1929-1932.
Authors: Robinson, A.L., Sextro, R.G.	Type: Journal Article

Report number: LBL-35943	Year: 1995
Title: The Influence of a Subslab Gravel Layer and Open Area on Soil-Gas and Radon Entry into Two Experimental Basements	Published in: Health Physics, Volume 69, Pages 367-377.
Authors: Robinson, A.L., Sextro, RG.	Type: Journal Article

Report number: LBL-38435	Year: 1995
Title: Wind-induced Ground Pressures Around a Single-family House	Published in: Journal of Wind Engineering and Industrial Aerodynamics, Volume 61, Pages 153-167.
Authors: Riley, W.J., Gadgil, A.J., Nazaroff, W.W.	Type: Journal Article

Report number: LBL-38194	Year: 1995
Title: Bayesian Analysis of the Relationship Between Indoor Radon Concentrations and Predicitive Variables in US Houses	Published in:
Authors: Revzan, K. L., Price, P. N., Nero, A. V.	Type: Journal Article

Report number: LBL-35818	Year: 1995
Title: Bayesian Prediction of Mean Indoor Radon Concentrations for Minnesota Counties	Published in:
Authors: Price, P. N., Nero, A. V., Gelman, A.	Type: Journal Article

Report number: LBL-35819	Year: 1995
Title: The Regression Effect as a Cause of the Nonlinear Relationship Between Short- and Long-Term Radon Concentration Measurements	Published in: Health Physics Society, Volume 69, Pages 111-114.
Authors: Price, P.N.	Type: Journal Article

Report number: LBL-36519	Year: 1995
Title: New Methods of Energy Efficient Radon Mitigation	Published in: Health Physics, Volume 68, Pages 689-698.
Authors: Fisk, W.J., Prill, R.J., Fisk, J.W., Bonnefous, Y.C., Gadgil, A.J., Riley, W.J.	Type: Journal Article

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Report number: LBNL-62262	Year: 2008
Title: Field and Laboratory Evaluation of a New Ramping Techniques for Duct Leakage Testing	Published in: ASHRAE Transactions, Volume 114, Pages 494-504.
Authors: Walker, I.S., Dickerhoff, D.J.	Type: Journal Article

Report number: LBNL-56483	Year: 2008
Title: Laser sheet light flow visualization for evaluating room air flows at reduced register air flow rates	Published in:
Authors: Walker, I.S., Claret, V., Smith, B.	Type: Report

Report number: LBNL-62344	Year: 2008
Title: Comparing Residential Furnace Blowers for Rating and Installed Performance	Published in: ASHRAE Transactions, Volume 114, Pages 187-195.
Authors: Walker, I.S.	Type: Journal Article
Abstract: The objective of this study was to assess the performance of residential furnace blowers for both heating, cooling and air distribution applications and to compare their performance at DOE/ARI rating conditions (for AFUE and SEER) and at real installed conditions. A testing program was undertaken at two laboratories to compare the performance of furnace blowers over a range of static pressure differences that included standard rating points and measured field test pressures. Three different combinations of blowers and residential furnaces were tested. The laboratory test results for blower power and airflow were combined with DOE2 models of building loads, models of air conditioner performance, standby power, as well as igniter and combustion air blower power to determine potential energy and peak demand impacts. The results show distinct differences between the two types of furnace blower motor technology: Permanent Split Capacitor (PSC) and more efficient Brushless Permanent Magnet (BPM). The high static pressure differences in real installations reduce the advantage that BPMs have at DOE/ARI rating conditions such that for cooling the two motor technologies have essentially the same power consumption although the reduction in airflow for the PSC results in 10% lower air conditioner efficiency. For heating, the advantage of the BPM is approximately halved when changing from standard test conditions to installed conditions, although the BPM has the advantage of maintaining airflow that avoids the safety implications of the PSC’s lower airflow. The BPM retains its advantage for multi-speed systems that can operate for significant numbers of hours in low-fire mode. To better reflect blower performance it is recommended that appliance rating test procedures be amended to use realistic system static pressures of between 0.5 and 0.8 in. water (125 and 200 Pa) and that utility rebate programs ensure that rebates are provided for multi-speed systems and/or systems that have a field measured low static pressure difference below 0.5 in. water (125 Pa).

Report number: LBNL-1209E	Year: 2008
Title: Evaluation of the Repeatability of the Delta Q Duct Leakage Testing Technique Including Investigation of Robust Analysis Techniques and Estimates of Weather Induced Uncertainty	Published in:
Authors: Dickerhoff, D., Walker, I.S.	Type: Report

Report number:	Year: 2007
Title: Emerging Requirements for Residential Thermostats in North America	Published in: The Sixth International Conference on Indoor Air Quality, Ventilation & Energy Conservation in Buildings 2007, Volume 1, Pages 899-903.
Authors: Meier, A., Walker, I.S.	Type: Conference Proceedings

Report number: LBNL-61743	Year: 2006
Title: Evaluation of a new ramping technique for duct leakage testing	Published in:
Authors: Walker, I.S., Dickerhoff, D.J.	Type: Report

Report number: LBNL-61868	Year: 2006
Title: Residential Furnace Blower Performance in U.S. Homes	Published in: Air Infiltration Review, Volume 28, Pages 3-4.
Authors: Walker, I.S.	Type: Journal Article
Abstract: Most heating (and cooling) systems in the U.S. use a centralized air handler or "furnace blower" to circulate conditioned air around the house. Although the space conditioning components themselves have become more efficient over the last couple of decades, residential forced air system blowers have not experienced similar improvement. The most common blowers have been shown by in-field testing to have efficiencies of only 10% to 15% corresponding to about 2 cfm (1 L/s) for every Watt of power consumption. These low efficiencies indicate that there is significant room for improvement of both electric motor and the aerodynamic performance of furnace blowers. Typical furnace blower power consumption in U.S. homes is about 500 to 700W and is increasing as larger new homes require larger heating and cooling systems. This is a significant power draw and represents 20 to 25% of the power consumed by a high efficiency air conditioner.

Report number: LBNL-61467	Year: 2006
Title: Residential Furnace Blower Performance	Published in:
Authors: Walker, I.S.	Type: Report

Report number: LBNL-51551	Year: 2003
Title: Evaluation of Commercially AvailableTechniques and Development of Simplified Methods for Measuring Grille Airflows in HVAC Systems	Published in:
Authors: Walker, Iain S., Wray, Craig P., Guillot, Cryil, Masson, S.	Type: Report
Abstract: This report discusses the accuracy of flow hoods for residential applications, based on laboratory tests and field studies. The results indicate that commercially available hoods are often inadequate to measure flows in residential systems, and that there can be a wide range of performance between different flow hoods. The errors are due to poor calibrations, sensitivity of existing hoods to grille flow non-uniformities, and flow changes from added flow resistance. We also evaluated several simple techniques for measuring register airflows that could be adopted by the HVAC industry and homeowners as simple diagnostics that are often as accurate as commercially available devices. Our test results also show that current calibration procedures for flow hoods do not account for field application problems. As a result, organizations such as ASHRAE or ASTM need to develop a new standard for flow hood calibration, along with a new measurement standard to address field use of flow hoods.

Report number: LBNL-51550	Year: 2003
Title: Evaluation of Flow Capture Techniques for Measuring HVAC Grille Airflows	Published in: ASHRAE Transactions, Volume 109.
Authors: Walker, I.S., Wray, C.P.	Type: Journal Article
Abstract: This paper discusses the accuracy of commercially available flow hoods for residential applications. Results of laboratory and field tests indicate these hoods can be inadequate to measure airflows in residential systems, and there can be large measurement discrepancies between different flow hoods. The errors are due to poor calibrations, sensitivity of the hoods to grille airflow non-uniformities, and flow changes from added flow resistance. It is possible to obtain reasonable results using some flow hoods if the field tests are carefully done, the grilles are appropriate, and grille location does not restrict flow hood placement. We also evaluated several simple flow capture techniques for measuring grille airflows that could be adopted by the HVAC industry and homeowners as simple diagnostics. These simple techniques can be as accurate as commercially available devices. Our test results also show that current calibration procedures for flow hoods do not account for field application problems. As a result, agencies such as ASHRAE or ASTM need to develop a new standard for flow hood calibration, along with a new measurement standard to address field use of flow capture techniques.

Report number: LBNL-53606	Year: 2003
Title: Improving Air Handler Efficiency in Residential HVAC Applications	Published in:
Authors: Walker, I.S., Mingee, M.D., Brenner, D.E.	Type: Report
Abstract: In continuing the development of energy efficiency standards, consideration has turned to air handlers used for heating and air conditioning of consumer residences. These air handlers have typical efficiencies of about 10% to 15% due to poor electric motor performance and aerodynamically poor fans and fan housings. This study was undertaken to examine some of these performance issues, under carefully controlled laboratory conditions, to support potential regulatory changes. In addition, this study examined the performance of a prototype air handler fan assembly that offers the potential for substantial increases in performance. This prototype and a standard production fan were tested in a full-scale duct system and test chamber at LBNL which was specifically designed for testing heating, ventilation, and air conditioning systems. The laboratory tests compared efficiency, total airflow, sensitivity to duct system flow resistance, and the effects of installation in a smaller cabinet. The test results showed that, averaged over a wide range of operating conditions, the prototype air handler had about twice the efficiency of the standard air handler and was less sensitive to duct system flow resistance changes. The performance of both air handlers was significantly reduced by reducing the space between the air handler and the cabinet it was installed in. Therefore any fan rating needs to be performed using the actual cabinet it will be used

Report number: LBNL-52084	Year: 2003
Title: Experimental Evaluation of Gas Filled Plenum Duct Insulation	Published in:
Authors: Walker, Iain S., Guillot, Cyril	Type: Report
Abstract: Forced-air heating and cooling system ducts are often located outside conditioned space in US houses. For these systems to perform efficiently it is important that these ducts be well insulated. Common practice is to use a glass fiber wrap around the ducts -- either field applied or more commonly, integrated into a flexible duct. Most duct insulation has an R-value of 4.2, with R6 and R8 ducts also occasionally used. With glass fiber insulation being about R4 per inch (RSI 0.28/cm), this adds 2 to 4 inches (50 to 100 mm) to the duct diameter. Some building codes are now requiring these higher insulation levels, for example, the EPA requires the use of R6 ducts (for Energy Star ducts: http://www.epa.gov/hhiptool/PDF/Duct_Spec_2002.PDF), and International Energy Conservation Code (BOCA 2003) requires R8 ducts. The difficulty with adding insulation to ducts is the increase in diameter of the ducts that makes them expensive to transport because they take up a large volume and are difficult to install in the confined spaces available for ducts in houses. The objective of this study was to evaluate Gas Filled Plenum (GFP) technology as an alternative duct insulation. GFP ducts have the potential to provide greater insulation levels than existing ducts (for a given thickness of insulation or size of duct) and provide cost savings in transportation. These transportation cost savings are based on the idea of shipping the GFP ducts empty and inflating them on-site. To evaluate this technology for ducts we constructed a prototype duct and determined both its flow and heat transfer resistance in LBNL's duct testing laboratories. The GFP technology works by encapsulating a gas (usually air -- but other noble gases such as Argon or Krypton can provide significant increases in thermal resistance with increased cost) in a metalized film jacket. A honeycomb structure is used to keep individual gas pockets small to minimize convection heat transfer. A metallic finish (usually aluminum) minimizes radiation heat transfer between the surfaces.

Report number: LBNL-43382	Year: 2003
Title: Evaluation of PEGIT Duct Connection System	Published in:
Authors: Walker, Iain S., Brenner, Douglas E., Sherman, Max H., Dickerhoff, Darryl J.	Type: Report
Abstract: Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system.

Report number: LBNL-55675	Year: 2003
Title: Integrating ducts into the conditioned space: Successes and challenges	Published in: Architectural Engineering Institute Conference, Austin, TX.
Authors: Siegel, J., Walker, I.S.	Type: Conference Proceedings
Abstract: In residential and light commercial construction in the United States, heating and cooling ducts are often located outside the thermal or pressure boundary of the conditioned space. This location is selected for aesthetic and space requirement reasons. Typical duct locations include attics, above dropped ceilings, crawlspaces, and attached garages. A wide body of literature has found that distribution system conduction and air leakage can cause 30-40% energy losses before cooling and heating air reaches the conditioned space. Recent innovative attempts at locating ducts in the conditioned space have had mixed results in terms of improving duct efficiency. Some of these strategies include cathedralizing attics (sealing and insulating at the attic roofline) and locating ducts in interstitial spaces. This paper reviews modeling studies that suggest substantial savings could be realized from these strategies and presents field measurements which reveal that construction planning and execution errors can prevent these strategies from being widely applied or from being effective when they are applied. These types of problems will need to be overcome for effective integration of ducts into the conditioned space.

Report number: LBNL-53547	Year: 2003
Title: Advanced Duct Sealant Testing	Published in:
Authors: Sherman, M.H., Walker, I.S.	Type: Journal Article
Abstract: Duct leakage is a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums, or branches in the duct system. At each of these connections, a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have shown that taped seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory (LBNL) has been testing sealant durability for several years. Accelerated test methods were used that continuously expose duct sealants to elevated temperatures (200 to 212°F (93 to 100°C)). We found that typical duct tape (i.e., fabric backed tapes with natural rubber adhesives) fails more rapidly than all other duct sealants. We also tested advanced tape products being developed by major manufacturers. The results of these tests showed that the major weaknesses of the tapes that fail are the use of natural rubber adhesives and the mechanical properties of the backing. The test results also showed that the current UL listings are inadequate for indicating durability and many tapes showed significant failure when testing using UL 181 B-FX procedures. In addition, the clamps required (but not evaluated) by UL-181B-FX had many failures and their durability also required evaluation. An accelerated test method developed by LBNL is being used as a basis for an ASTM standard under sub-committee E6.41.

Report number: LBNL-49749	Year: 2002
Title: The Delta Q method of testing the air leakage of ducts	Published in: Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 1, Pages 327-338.
Authors: Walker, I.S., Dickerhoff, D.J., Sherman, M.H.	Type: Conference Proceedings
Abstract: The DeltaQ test has been developed in order to provide better estimates of forced air system air leakage for use in energy efficiency calculations and for compliance testing of duct systems. The DeltaQ test combines a model of the house and duct system with the results of house pressurization tests with the air handler on and off to determine the duct leakage air flows to outside conditioned space at operating conditions. The key advantage of the DeltaQ test over other methods is that it determines the air leakage flows directly, rather than requiring interpretation of indirect measurements. The results from over 200 field and laboratory tests are presented. The laboratory tests have shown that the DeltaQ repeatability uncertainties are typically 1% or less of system fan flow and that the accuracy of the test is between 1.3% and 2.5% of fan flow (or 13 cfm to 25 cfm (6 to 12 l/s) for this system).

Report number: LBNL-49339	Year: 2002
Title: Modeling Particle Deposition on HVAC Heat Exchangers	Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 521-526.
Authors: Siegel, J.A., Nazaroff, W.W.	Type: Conference Proceedings
Abstract: Fouling of fin-and-tube heat exchangers by particle deposition leads to diminished effectiveness in supplying ventilation and air conditioning. This paper explores mechanisms that cause particle deposition on heat exchanger surfaces. We present a model that accounts for impaction, diffusion, gravitational settling, and turbulence. Simulation results suggest that some submicron particles deposit in the heat exchanger core, but do not cause significant performance impacts. Particles between 1 and 10 µm deposit with probabilities ranging from 1 -- 20 % with fin edge impaction representing the dominant mechanism. Particles larger than 10 µm deposit by impaction on refrigerant tubes, gravitational settling on fin corrugations, and mechanisms associated with turbulent airflow. The model results agree reasonably well with experimental data, but the deposition of larger particles at high velocities is underpredicted. Geometric factors, such as discontinuities in the fins, are hypothesized to be responsible for the discrepancy.

Report number: LBNL-50008	Year: 2002
Title: Comparison between predicted duct effectiveness from proposed ASHRAE standard 152P and measured field data for residential forced air cooling systems	Published in: ASHRAE Transactions, Volume 109.
Authors: Siegel, J.A., McWilliams, J.A., Walker, I.S.	Type: Journal Article
Abstract: The proposed ASHRAE Standard 152P "Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems" (ASHRAE 2002) has recently completed its second public review. As part of the standard development process, this study compares the forced air distribution system ratings provided by the public review draft of Standard 152P to measured field results. 58 field tests were performed on cooling systems in 11 homes in the summers of 1998 and 1999. Seven of these houses had standard attics with insulation on the attic floor and a well-vented attic space. The other four houses had unvented attics where the insulation is placed directly under the roof deck and the attic space is not deliberately vented. Each house was tested under a range of summer weather conditions at each particular site, and in some cases the amount of duct leakage was intentionally varied. The comparison between 152P predicted efficiencies and the measured results includes evaluation of the effects of weather, duct location, thermal conditions, duct leakage, and system capacity. The results showed that the difference between measured delivery effectiveness and that calculated using proposed Standard 152P is about 5 percentage points if weather data, duct leakage and air handler flow are well known. However, the accuracy of the standard is strongly dependent on having good measurements of duct leakage and system airflow. Given that the uncertainty in the measured delivery effectiveness is typically also about 5 percentage points, the Standard 152P results are acceptably close to the measured data.

Report number: LBNL-49700	Year: 2002
Title: A study of pressure losses in residential air distribution systems	Published in: Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 1, Pages 1-14.
Authors: Abushakra, B., Walker, I.S., Sherman, M.H.	Type: Conference Proceedings
Abstract: An experimental study was conducted to evaluate the pressure drop characteristics of residential duct system components that are either not available or not thoroughly (sometimes incorrectly) described in existing duct design literature. The tests were designed to imitate cases normally found in typical residential and light commercial installations. The study included three different sizes of flexible ducts, under different compression configurations, splitter boxes, supply boots, and a fresh air intake hood. The experimental tests conformed to ASHRAE Standard 120P -- Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings. The flexible duct study covered compressibility and bending effects on the total pressure drop, and the results showed that the available published references tend to underestimate the effects of compression in flexible ducts that can increase pressure drops by up to a factor of nine. The supply boots were tested under different configurations including a setup where a flexible duct elbow connection was considered as an integral part of the supply boot. The supply boots results showed that diffusers can increase the pressure drop by up to a factor of two in exit fittings, and the installation configuration can increase the pressure drop by up to a factor of five. The results showed that it is crucial for designers and contractors to be aware of the compressibility effects of the flexible duct, and the installation of supply boots and diffusers.

Report number: LBNL-51099	Year: 2002
Title: Longevity of duct tape in residential air distribution systems: 1-D, 2-D, and 3-D joints	Published in:
Authors: Abushakra, B.	Type: Report
Abstract: No Abstract available

Report number: LBNL-47382	Year: 2001
Title: Evaluation of flow hood measurements for residential register flows	Published in:
Authors: Walker, I.S., Wray, C.P., Dickerhoff, D.J., Sherman, M.H.	Type: Journal Article
Abstract: Flow measurement at residential registers using flow hoods is becoming more common. These measurements are used to determine if the HVAC system is providing adequate comfort, appropriate flow over heat exchangers and in estimates of system energy losses. These HVAC system performance metrics are determined by using register measurements to find out if individual rooms are getting the correct airflow, and in estimates of total air handler flow and duct air leakage. The work discussed in this paper shows that commercially available flow hoods are poor at measuring flows in residential systems. There is also evidence in this and other studies that flow hoods can have significant errors even when used on the non-residential systems they were originally developed for. The measurement uncertainties arise from poor calibrations and the sensitivity of exiting flow hoods to non-uniformity of flows entering the device. The errors are usually large -- on the order of 20% of measured flow, which is unacceptably high for most applications. Active flow hoods that have flow measurement devices that are insensitive to the entering air flow pattern were found to be clearly superior to commercially available flow hoods. In addition, it is clear that current calibration procedures for flow hoods may not take into account any field application problems and a new flow hood measurement standard should be developed to address this issue.

Report number: LBNL-47622	Year: 2001
Title: Simulation of Residential HVAC System Performance	Published in: Proceedings of the ESIM 2001 Conference, Ontario, Canada, Pages 43-50.
Authors: Walker, I.S., Siegel, J.A., Degenetais, G.	Type: Conference Proceedings
Abstract: In many parts of North America residential HVAC systems are installed outside conditioned space. This leads to significant energy losses and poor occupant comfort due to conduction and air leakage losses from the air distribution ducts. In addition, cooling equipment performance is sensitive to air flow and refrigerant charge that have been found to be far from manufacturers specifications in most systems. The simulation techniques discussed in this paper were developed in an effort to provide guidance on the savings potentials and comfort gains that can be achieved by improving ducts (sealing air leaks) and equipment (correct air-flow and refrigerant charge). The simulations include the complex air flow and thermal interactions between duct systems, their surroundings and the conditioned space. They also include cooling equipment response to air flow and refrigerant charge effects. Another key aspect of the simulations is that they are dynamic -- which accounts for cyclic losses from the HVAC system and the effect of cycle length on energy and comfort performance.

Report number: LBNL-47308	Year: 2001
Title: Development of a New Duct leakage Test: Delta Q	Published in:
Authors: Walker, I.S., Sherman, M.H., Wempen, J., Wang, D., McWilliams, J.A., Dickerhoff, D.J.	Type: Report
Abstract: Several studies (Francisco and Palmiter 1997 and 1999, Andrews et al. 1998, and Siegel et al. 2001) have shown that the duct system efficiency cannot be reliably determined without good estimates of duct leakage. Specifically, for energy calculations, it is the duct leakage air flow to outside at operating conditions that is required. Existing test methods either precisely measure the size of leaks (but not the flow through them at operating conditions), or measure these flows with insufficient accuracy. The DeltaQ duct leakage test method was developed to provide improved estimates of duct leakage during system operation. In this study we developed the analytical calculation methods and the test procedures used in the DeltaQ test. As part of the development process, we have estimated uncertainties in the test method (both analytically and based on field data) and designed automated test procedures to increase accuracy and reduce the contributions of operator errors in performing field tests. In addition, the test has been evaluated in over 100 houses by several research teams to show that it can be used in a wide range of houses and to aid in finding limits or problems in field applications. The test procedure is currently being considered by ASTM as an update of an existing duct leakage standard.

Report number: LBNL-43371	Year: 2001
Title: Sensitivity of forced air distribution system efficiency to climate, duct location, air leakage and insulation	Published in:
Authors: Walker, I.S.	Type: Report
Abstract: This study was performed in order to find suitable efficiency and leakage specifications for Energy Star duct systems and provide recommendations on duct insulation specifications. This analysis looks at a typical house, with a selection of duct locations, climates, duct insulation (R-value), and duct leakage. A set of calculations were performed with reduced capacity and airflow to look at the effect of variable capacity systems. This was done to address concerns regarding the increased efficiency of multi-capacity equipment due to good part load performance and how these efficiency gains may be offset by increased duct losses. The duct system efficiencies were calculated using the procedures in proposed ASHRAE Standard 152P "Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems" (ASHRAE 1999). This proposed ASHRAE Standard can be used to calculate duct efficiency for both design and seasonal weather conditions. In this report, the seasonal efficiencies are used for most of the analysis because they are the most appropriate for estimating energy consumption in buildings. The effects at peak conditions are examined for changing duct insulation in order to provide preliminary estimates of the potential responses to time of use pricing. The study was performed in two parts. The first part focused on duct leakage and the second part on duct insulation. The HVAC systems in the two parts share many attributes, however, they differ in detail and so are treated separately here. All the calculation results are summarized in tables in the Appendix, and specific results are given in the text.

Report number: LBNL-47669	Year: 2001
Title: Deposition of biological aerosols on HVAC heat exchangers	Published in:
Authors: Siegel, J.A., Walker, I.S.	Type: Report
Abstract: Many biologically active materials are transported as bioaerosols 1-10 µm in diameter. These particles can deposit on cooling and heating coils and lead to serious indoor air quality problems. This paper investigates several of the mechanisms that lead to aerosol deposition on fin and tube heat exchangers. A model has been developed that incorporates the effects of several deposition mechanisms, including impaction, Brownian and turbulent diffusion, turbophoresis, thermophoresis, diffusiophoresis, and gravitational settling. The model is applied to a typical range of air velocities that are found in commercial and residential HVAC systems 1 -- 6 m/s (200 -- 1200 ft/min), particle diameters from 1 -- 8 µm, and fin spacings from 3.2 -- 7.9 fins/cm (8 -- 16 fins/inch or FPI). The results from the model are compared to results from an experimental apparatus that directly measures deposition on a 4.7 fins/cm (12 FPI) coil. The model agrees reasonably well with this measured data and suggests that cooling coils are an important sink for biological aerosols and consequently a potential source of indoor air quality problems.

Report number: LBNL-47668	Year: 2001
Title: Fouling of HVAC fin and tube heat exchangers	Published in:
Authors: Siegel, Jeffrey	Type: Report
Abstract: Fin and tube heat exchangers are used widely in residential, commercial and industrial HVAC applications. Invariably, indoor and outdoor air contaminants foul these heat exchangers. This fouling can cause decreased capacity and efficiency of the HVAC equipment as well as indoor air quality problems related to microbiological growth. This paper describes laboratory studies to investigate the mechanisms that cause fouling. The laboratory experiments involve subjecting a 4.7 fins/cm (12 fins/inch) fin and tube heat exchanger to an air stream that contains monodisperse particles. Air velocities ranging from 1.5 -- 5.2 m/s (295 ft/min -- 1024 ft/min) and particle sizes from 1 -- 8.6 µm are used. The measured fraction of particles that deposit as well as information about the location of the deposited material indicate that particles greater than about 1 µm contribute to fouling. These experimental results are used to validate a model that describes the relative importance of several deposition mechanisms including impaction, Brownian diffusion, turbophoresis and gravitational settling. The analysis is extended to apply to different fin spacings and particle sizes typical of those found in indoor air.

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-43723	Year: 2000
Title: Effects of Duct Improvement and ENERGYSTAR Equipment on Comfort and Energy Efficiency	Published in:
Authors: Walker, I.S., Sherman, M.H., Siegel, J.A., Modera, M.P.	Type: Report
Abstract: Residential thermal distribution systems have significant energy and comfort implications due to losses from the distribution system in the form of leakage and conduction and poor distribution from room-to- room within the house. Also, poor mechanical equipment performance, and the interactions between the distribution system and the equipment act to further reduce system capacity and thermal comfort. An example of duct system and equipment interaction is the that airflow over the indoor coils changes the efficiency, capacity and humidity removal of the system resulting in comfort, energy consumption and efficiency changes. To determine if there are any differences in the interactions depending on whether or not the equipment is ENERGYSTAR rated, two houses were tested with standard (SEER10) air conditioners and then retrofitted with ENERGYSTAR (SEER 13) equipment. In addition, the effect of duct leakage was examined by adding leaks to the systems under test. The original plan had been to seal the duct systems, but they were found to be not very leaky. Leakage was added in order to show the effect of reduced leakage. Four additional houses were tested as part of a companion study (Walker et al. (1999)) that did not have equipment changes. Selected measurement results from these houses are presented where appropriate. This report is in two main parts. The first part discusses the field measurement techniques and results. The second part examines efforts to model distribution system performance using a sophisticated computer simulation program called REGCAP. REGCAP has been developed to specifically include the interactions of duct systems with their surroundings (In this study the duct surroundings are attic spaces). Lastly, a brief summary of related thermal distribution system research is included at the end of the report.

Report number: LBNL-43381	Year: 2000
Title: Assessing the longevity of residential duct sealants	Published in: Proceedings of the RILEM 3rd International Symposium, France, Pages 71-86.
Authors: Walker, I.S.	Type: Conference Proceedings

Report number: LBL-45315	Year: 2000
Title: Delivering Tons to the Register: Energy Efficient Design and Operation of Residential Cooling System	Published in: Proceedings of the ACEEE Summer Study 2000, Pacific Grove, CA, Volume 1, Pages 295-306.
Authors: Siegel, J.A., Walker, I.A., Sherman, M.H.	Type: Conference Proceedings

Report number: LBNL-45423	Year: 2000
Title: Stopping Duct Quacks: Longevity of Residential Duct Sealants	Published in: Proceedings of the ACEEE 2000 Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 1, Pages 273-284.
Authors: Sherman, M.H., Walker, I.S., Dickerhoff, D.J.	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-43724	Year: 1999
Title: Distribution effectiveness and impacts on equipment sizing for residential thermal distribution systems	Published in:
Authors: Walker, I.S., Sherman, M.H., Siegel, J.A.	Type: Report
Abstract: Previous studies (including earlier phases of this research project) have shown that losses from residential thermal distribution systems have significant energy and comfort implications. This study looks at the potential for improvement of thermal distribution systems and the possibility of reducing equipment size as a result. These distribution system and equipment interactions were examined through field testing and computer simulation. In addition, this report outlines our efforts to transfer the results of this research to the marketplace so as to reduce energy losses and improve thermal comfort. This study describes the results of efforts made during the Transitional Phase of this Residential Thermal Distribution Systems research. Results of earlier Phases were described in Walker et al. (1997 and 1998).

Report number: LBNL-42182	Year: 1999
Title: COMIS -- An International Multizone Air-Flow and Contaminant Transport Model	Published in: Energy and Buildings, Volume 30, Pages 3-18.
Authors: Feustel, H.E.	Type: Journal Article

Report number: LBNL-40587	Year: 1998
Title: Field Measurements of the Interactions between Furnaces and Forced Air Distribution Systems	Published in: ASHRAE Transactions, Volume 104, Pages 1805-1816.
Authors: Walker, I.S., Modera, M.P.	Type: Journal Article
Abstract: Measurements on three gas and two electric furnaces have been made to examine the field performance of these furnaces and their interactions with their forced-air distribution systems. The distribution systems were retrofitted as part of this study and the impact of retrofitting on furnace performance is discussed. In addition to field measurements, this paper will discuss how forced-air furnace systems are treated in proposed ASHRAE Standard 152P, and applies the resulting equations to the systems tested in the field. The distribution system calculations in Standard 152P are compared to the current methods employed in the "Furnaces" chapter of ASHRAE's HVAC Systems and Equipment Handbook, showing how the distribution system efficiencies calculated using Standard 152P can be incorporated into the handbook.

Report number: LBNL-40588	Year: 1998
Title: Technical Background for Default Values used for Forced Air Systems in Proposed ASHRAE Standard 152P	Published in: ASHRAE Transactions, Volume 104, Pages 1360-1375.
Authors: Walker, I.S.	Type: Journal Article
Abstract: ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) includes default values for many of the input parameters required to calculate delivery system efficiencies. These default values have several sources: measured field data in houses, laboratory testing, simple heat transfer analyses, etc. This paper will document and discuss these default values and their sources for forced air systems.

Report number: LBNL-41957	Year: 1998
Title: Saving Tons at the Register	Published in: Proceedings of the 1998 ACEEE Summer Study on Energy Effciency in Buildings, Pacific Grove, CA, Volume 1, Pages 367-383.
Authors: Walker, I., Siegel, J., Brown, K., Sherman, M.	Type: Conference Proceedings
Abstract: Duct losses have a significant effect on the efficiency of delivering space cooling to U.S. homes. This effect is especially dramatic during peak demand periods where half of the cooling equipment's output can be wasted. Improving the efficiency of a duct system can save energy, but can also allow for downsizing of cooling equipment without sacrificing comfort conditions. Comfort, and hence occupant acceptability, is determined not only by steady-state temperatures, but by how long it takes to pull down the temperature during cooling start-up, such as when the occupants come home on a hot summer afternoon. Thus the delivered tons of cooling at the register during start-up conditions are critical to customer acceptance of equipment downsizing strategies. We have developed a simulation technique which takes into account such things as weather, heat-transfer (including hot attic conditions), airflow, duct tightness, duct location and insulation, and cooling equipment performance to determine the net tons of cooling delivered to occupied space. Capacity at the register has been developed as an improvement over equipment tonnage as a system sizing measure. We use this concept to demonstrate that improved ducts and better system installation is as important as equipment size, with analysis of pull-down capability as a proxy for comfort. The simulations indicate that an improved system installation including tight ducts can eliminate the need for almost a ton of rated equipment capacity in a typical new 2,000 square foot house in Sacramento, California. Our results have also shown that a good duct system can reduce capacity requirements and still provide equivalent cooling at start-up and at peak conditions.

Report number: LBNL-41118	Year: 1998
Title: Leakage Diagnostics, Sealant Longevity, Sizing and Technology Transfer in Residential Thermal Distribution Systems	Published in:
Authors: Walker, I., Sherman, M., Modera, M., Siegel, J.	Type: Report
Abstract: This field study concentrated on measurement of duct leakage to outside the conditioned space because this is most useful in energy calculations, e.g., proposed ASHRAE Standard 152P (ASHRAE 1997). For room by room load/comfort requirements, the total duct leakage (including leaks to conditioned space) is more appropriate, particularly for additional comfort considerations. The objective of this field study is to help to identify major sources of uncertainty and to quantify the trade-offs between different test methods. The identification of the areas requiring significant improvement will aid in future development of duct leakage test methods. For example, during the course of this study a new method for correcting house pressure tests to account for the presence of duct leakage in measured envelope leakage was developed. Each of the measurement techniques investigated has resulted from a different set of priorities and hence compromises. Thus each one of them is measuring a different physical quantity, although they all report the same parameter -- duct leakage to outside at operating conditions. Given that real houses do not meet all of the simplifying assumptions that must be made to achieve similarity, the same numbers from each test method are not expected. Potentially these differences can be quite large and one of the benefits of field measurement is that the differences in the measurements helps put a realistic bound on how different some of these leakage diagnostics may be. To evaluate current duct leakage diagnostic methods, field tests were performed in 17 houses. The field tests were divided into two parts. The first part was performed in occupied S.F. Bay Area houses. The second part was performed in new unoccupied houses (some with unfinished interiors) in Irvine, CA. In the Bay Area, nine houses were tested using four diagnostic techniques.

Report number: LBNL-41434	Year: 1998
Title: Can Duct-Tape Take the Heat?	Published in: Home Energy, Volume 15, Pages 14.
Authors: Sherman, M.H., Walker, I.S.	Type: Journal Article

Report number: LBL-38537	Year: 1996
Title: Field Measurements of Efficiency and Duct Retrofit Effectiveness in Residential Forced Air Distribution Systems	Published in: Proceedings of the 1996 ACEEE Summer Study on Energy Efficiency in Buildings, Pacific Grove, CA, Volume 1, Pages 147-156.
Authors: Jump, D.A., Walker, I.S., Modera, M.P.	Type: Conference Proceedings
Abstract: Forced air distribution systems can have a significant impact on the energy consumed in residences. It is common practice in U.S. residential buildings to place such duct systems outside the conditioned space. This results in the loss of energy by leakage and conduction to the surroundings. In order to estimate the magnitudes of these losses, 24 houses in the Sacramento, California, area were tested before and after duct retrofitting. The systems in these houses included conventional air conditioning, gas furnaces, electric furnaces and heat pumps. The retrofits consisted of sealing and insulating the duct systems. The field testing consisted of the following measurements: leakage of the house envelopes and their ductwork, flow through individual registers, duct air temperatures, ambient temperatures, surface areas of ducts, and HVAC equipment energy consumption. These data were used to calculate distribution system delivery efficiency as well as the overall efficiency of the distribution system including all interactions with building load and HVAC equipment. Analysis of the test results indicate an average increase in delivery efficiency from 64% to 76% and a corresponding average decrease in HVAC energy use of 18%. This paper summarizes the pre- and post-retrofit efficiency measurements to evaluate the retrofit effectiveness, and includes cost estimates for the duct retrofits. The impacts of leak sealing and insulating will be examined separately.

Report number: LBNL-35445	Year: 1995
Title: New Technologies for Residential HVAC Ducts	Published in:
Authors: Treidler, B., Modera, M.	Type: Journal Article

Report number: LBL-36048	Year: 1995
Title: Improved Modelling of HVAC System/Envelope Interactions in Residential Buildings	Published in: Proceedings of the ASME/JSME/JSES International Solar Energy Conference, Maui, HI, Volume 1, Pages 245-252.
Authors: Modera, M.P., Treidler, B.	Type: Conference Proceedings

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Report number: LBNL-254E	Year: 2008
Title: Interim Report: VOC and aldehyde emissions in four FEMA temporary housing units	Published in:
Authors: Maddalena, R.L., Russell, M.L., Sullivan, D.P., Apte, M.G.	Type: Report
Abstract: Four unoccupied FEMA temporary housing units (THUs) were studied to assess their indoor emissions of volatile organic compounds including formaldehyde. Measurement of whole-THUVOC and aldehyde emission factors (µg h-1 per m2 of floor area) for each of the four THUs were made at FEMA’s Purvis MS staging yard using a mass balance approach. Measurements were made in the morning, and again in the afternoon in each THU. Steady-state indoor formaldehyde concentrations ranged from 378 µg m-3 (0.31ppm) to 632 µg m-3 (0.52 ppm) in the AM, and from 433 µg m-3 (0.35 ppm) to 926 µg m-3 (0.78 ppm) in the PM. THU air exchange rates ranged from 0.15 h-1 to 0.39 h-1. A total of 45 small (approximately 0.025 m2) samples of surface material, 16 types, were collected directly from the four THUs and shipped to Lawrence Berkeley Laboratory. The material samples were analyzed for VOC and aldehyde emissions in small stainless steel chambers using a standard, accurate mass balance method. Quantification of VOCs was done via gas chromatography – mass spectrometry and low molecular weight aldehydes via high performance liquid chromatography. Material specific emission factors (µg h-1 per m2 of material) were quantified. Approximately 80 unique VOCs were tentatively identified in the THU field samples, of which forty-five were quantified either because of their toxicological significance or because their concentrations were high. Whole-trailer and material specific emission factors were calculated for 33 compounds. The THU emission factors and those from their component materials were compared against those measured from other types of housing and the materials used in their construction. Whole THU emission factors for most VOCs were typically similar to those from comparative housing. The three exceptions were exceptionally large emissions of formaldehyde and TMPD-DIB (a common plasticizer in vinyl products), and somewhat elevated for phenol. Of these three compounds, formaldehyde was the only one with toxicological significance at the observed concentrations. Whole THU formaldehyde emissions ranged from 173 to 266 µg m-2 h-1 in the morning and 257 to 347 µg m-2 h-1 in the afternoon. Median formaldehyde emissions in previously studied site-built and manufactured homes were 31 and 45 µg m-2 h-1, respectively. Only one of the composite wood materials that was tested appeared to exceed the HUD formaldehyde emission standard (430 µg/m2 h-1 for particleboard and 130 µg/m2 h-1 for plywood). The high loading factor (material surface area divided by THU volume) of composite wood products in the THUs and the low fresh air exchange relative to the material surface area may be responsible for the excessive concentrations observed for some of the VOCs and formaldehyde.

Report number: LBNL-63480	Year: 2007
Title: Evidence of acid-base interactions between amines and model indoor surfaces by ATR-FTIR spectroscopy	Published in: Atmospheric Environment, Volume 41, Pages 3177-3181.
Authors: Destaillats, H., Singer, B.C., Gundel, L A.	Type: Journal Article

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 �g m-3 for individual terpenoids, including �-terpinene (90-120), d-limonene (1000-1100), terpinolene (900-1300), and �-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-59781	Year: 2006
Title: Indoor Residential Chemical Exposures as Risk Factors for Asthma and Allergy in Infants and Children: A Review	Published in: Proceedings of Healthy Buildings 2006 Conference, Volume 1, Pages 151-156.
Authors: Mendell, M.	Type: Conference Proceedings
Abstract: Most research into effects of residential indoor air exposures on asthma and allergies has focused on exposures to biologic allergens, moisture and mold, endotoxin, or combustion byproducts. This paper briefly reviews reported findings on associations of asthma or allergy in infants or children with risk factors related to indoor chemical emissions from residential materials or surface coatings. Associations, some strong (e.g., odds ratios up to 13), were reported. The most frequently identified risk factors were formaldehyde, aromatic organic compounds such as toluene and benzene, plastic materials and plasticizers, and recent painting. Exposures and consequent effects from indoor sources may be exacerbated by decreased ventilation. Identified risk factors may be proxies for correlated exposures. Findings suggest the frequent occurrence of important but preventable effects on asthma and allergy in infants and children worldwide from modern residential building materials and coatings.

Report number: LBNL-57505	Year: 2006
Title: Effect of ozone on nicotine desorption from model surfaces: evidence for heterogeneous chemistry	Published in: Environmental Science and Technology, Volume 40, Pages 1799-1805.
Authors: Destaillats, H., Singer, B.C., Lee, S.K., Gundel, L A.	Type: Journal Article
Abstract: The interaction of ozone with nicotine sorbed to Teflon or cotton surfaces was investigated in an environmental chamber by monitoring nicotine desorption over a week following equilibration in dry or humid air (65-70 % RH). The Teflon and cotton surfaces had N2-BET surface areas of 0.19 and 1.17 m2 g-1, and water mass uptakes (at 70 % RH) of 0 and 7.1 % respectively. In dry air, gas phase nicotine concentrations decreased with respect to baseline (no O3) levels by 2 orders of magnitude for Teflon after 50 h at 20-45 ppb O3, and by a factor of 10 for cotton after 100 h with 13-15 ppb O3. The ratios of pseudo first-order rate constants for surface reaction (r) to long-term desorption (k) were r/k = 3.5 and 2.0 for Teflon and cotton surfaces, respectively. Formaldehyde, N-methylformamide, nicotinaldehyde and cotinine were identified as oxidation products, indicating that the pyrrolidinic N was the site of electrophilic attack by O3. The presence of water vapor had no effect on the nicotine-O3 reaction on Teflon surfaces. By contrast, nicotine desorption profiles from cotton in humid air were identical in the presence or absence of ozone. The latter phenomenon is ascribed to complete inhibition of ozone-nicotine surface reactions by co-sorbed water through decomposition of ozone in the aqueous surface film and/or interactions of nicotine with water that reduced its reactivity towards ozone. Oxidative losses of sorbed nicotine and reduction in its re-emission could attenuate possible biases in use of nicotine as a tracer for environmental tobacco smoke.

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-58785	Year: 2006
Title: Indoor Secondary Pollutants from Household Product Emissions in the Presence of Ozone: A Bench-Scale Chamber Study	Published in: Environmental Science and Technology, Volume 40, Pages 4421-4428.
Authors: Destaillats, H., Lunden, M., Singer, B.C., Coleman, B.K., Hodgson, A., Weschler, C.J., Nazaroff, W.	Type: Journal Article
Abstract: Ozone-driven chemistry is a major source of indoor secondary pollutants of health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and oxidation products were measured. Formaldehyde was a predominant oxidation byproduct for the three studied products, with yields under most conditions of 20-30% with respect to ozone consumed. Acetaldehyde, acetone, glycolaldehyde, formic acid and acetic acid were each also detected for two or three of the products. Immediately upon mixing of reactants, a scanning mobility particle sizer detected particle nucleation events that were followed by a significant degree of ultrafine particle growth. The production of secondary gaseous pollutants and particles depended primarily on the ozone level and was influenced by other parameters such as the air-exchange rate. Hydroxyl radical concentrations in the range 0.04-200 × 105 molecules cm-3 were measured. OH concentrations were observed to vary strongly with residual ozone level in the chamber, which was in the range 1 – 25 ppb, as is consistent with expectations from a simplified kinetic model. In a separate test, we exposed the dry residue of two products to ozone in the chamber and observed the formation of gas-phase and particle-phase secondary oxidation products.

Report number: LBNL-57030	Year: 2005
Title: Effect of Residential Ventilation Techniques for Hot and Humid Climates on Indoor Concentrations of Volatile Organic Compounds	Published in:
Authors: Hodgson, A.T., Moyer, N., Beal, D.	Type: Report
Abstract: Mechanical ventilation may be necessary to provide adequate ventilation in new houses due to the relatively low rates of infiltration achieved in new construction. However, in hot and humid climates, increased ventilation may raise indoor humidity to an undesirable level. A study was undertaken by the Florida Solar Energy Center (FSEC) to evaluate the humidity effects of different mechanical ventilation strategies for such climates. The study was conducted in a new 141-m2 manufactured house sited at the FSEC campus. Six mechanical ventilation strategies were evaluated for their ability to control indoor humidity levels over 14-day periods with simulated occupancy. A base case with no extra ventilation served as a control. The strategies consisted of spot exhaust ventilation, use of an energy recovery ventilator, and four configurations of a dedicated outdoor air supply system, one of which included use of a room dehumidifier. The objective of the study described here was to determine the impacts of the ventilation techniques on the concentrations and emission rates of indoor-generated formaldehyde and other volatile organic compounds (VOCs). Measurements of indoor and outdoor VOCs were made both by active and passive sampling during each ventilation condition. The emission factors of most VOCs remained relatively constant across all experiments with mechanical ventilation. The case with the dehumidifier and the outside air supply fan programmed to be on at least one-third of the time was shown to provide the generally lowest indoor VOC concentrations because it was able to operate at a higher ventilation rate while maintaining 50% indoor relative humidity.

Report number: LBNL-57041	Year: 2005
Title: Implementation of Source Reduction Practices for Volatile Organic Compounds in Manufactured House Construction: Pilot Demonstration Project	Published in:
Authors: Hodgson, A.T., Beal, D.	Type: Report
Abstract: Indoor air quality (IAQ) in new houses, particularly occupant's inhalation exposure to toxic, irritant and odorous chemicals, has received comparatively little attention among house builders and product manufacturers. The volatile organic compounds (VOCs) of potential concern in new houses include formaldehyde, acetaldehyde, acetic acid and naphthalene. These VOCs are emitted by a variety of wood products and other materials used to finish the interiors of most houses. This study sought to demonstrate the efficacy of several low-cost measures intended to reduce the emissions and concentrations of formaldehyde and other VOCs in the production of a single manufactured house. The study was conducted as a collaborative effort with a nationwide producer of such houses. Two doublewide houses were selected for study. One received modifications to the cabinetry and countertop materials, a weatherization barrier under a low-emitting carpet system, and low VOC-impact interior paints. The other, produced at about the same time, did not have IAQ modifications and served as the control. The houses were installed on nearby lots in a sales center and were decorated for use as model homes. Samples for formaldehyde, acetaldehyde and other VOCs were collected in the houses at approximately three and six months after they were fully operational. Outdoor air ventilation rates also were measured. The emission rates of higher molecular-weight aldehydes and terpene hydrocarbons predominantly associated with the plywood subfloor were reduced in the modified house likely due to the use of the weatherization barrier. The low-VOC paints substantially reduced the concentration of a major volatile component of interior wall paints. However, the concentrations and emissions of formaldehyde unexpectedly were higher in the modified house (e.g., the emission rate was a factor of two higher). The remainder of the study was spent diagnosing this difference. The heating and air conditioning system was eliminated as a possible source. Measurements of formaldehyde emissions from the particleboard components of the furnishings revealed that the new wood furniture purchased to decorate the modified house, but not the control house, was the likely source of the excess formaldehyde emissions. When approximately adjusted for the emissions from the new furniture, the formaldehyde emission rate in the modified house was nearly equivalent to rate in the control house. This emission rate resulted in formaldehyde concentrations below 50 ppb in the control house.

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-53943	Year: 2004
Title: Sorption of organic gases in a furnished room	Published in: Atmospheric Environment, Volume 38, Pages 2483-2494.
Authors: Singer, B.C., Revzan, K., Hotchi, T., Hodgson, A., Brown, N.J.	Type: Journal Article

Report number: LBNL-49577	Year: 2004
Title: Fomaldehyde as a Basis for Residential Ventilation Rates	Published in: Indoor Air, Volume 14, Pages 2-9.
Authors: Sherman, M.H., Hodgson, A.T.	Type: Journal Article
Abstract: Traditionally, houses in the U.S. have been ventilated by passive infiltration in combination with active window opening. However in recent years, the construction quality of residential building envelopes has been improved to reduce infiltration, and the use of windows for ventilation also may have decreased due to a number of factors. Thus, there has been increased interest in engineered ventilation systems for residences. The amount of ventilation provided by an engineered system should be set to protect occupants from unhealthy or objectionable exposures to indoor pollutants, while minimizing energy costs for conditioning incoming air. Determining the correct ventilation rate is a complex task, as there are numerous pollutants of potential concern, each having poorly characterized emission rates, and poorly defined acceptable levels of exposure. One ubiquitous pollutant in residences is formaldehyde. The sources of formaldehyde in new houses are reasonably understood, and there is a large body of literature on human health effects. This report examines the use of formaldehyde as a means of determining ventilation rates and uses existing data on emission rates of formaldehyde in new houses to derive recommended levels. Based on current, widely accepted concentration guidelines for formaldehyde, the minimum and guideline ventilation rates for most new houses are 0.28 and 0.5 air changes per hour, respectively.

Report number: LBNL-56272	Year: 2004
Title: Volatile Organic Compound Concentrations and Emission Rates Measured over One Year in a New Manufactured House	Published in:
Authors: Hodgson, A., Nabinger, S.J., Persily, A.	Type: Report
Abstract: A study to measure indoor concentrations and emission rates of volatile organic compounds (VOCs), including formaldehyde, was conducted in a new, unoccupied manufactured house installed at the National Institute of Standards and Technology (NIST) campus. The house was instrumented to continuously monitor indoor temperature and relative humidity, heating and air conditioning system operation, and outdoor weather. It also was equipped with an automated tracer gas injection and detection system to estimate air change rates every 2 h. Another automated system measured indoor concentrations of total VOCs with a flame ionization detector every 30 min. Active samples for the analysis of VOCs and aldehydes were collected indoors and outdoors on 12 occasions from August 2002 through September 2003. Individual VOCs were quantified by thermal desorption to a gas chromatograph with a mass spectrometer detector (GC/MS). Formaldehyde and acetaldehyde were quantified by high performance liquid chromatography (HPLC). Weather conditions changed substantially across the twelve active sampling periods. Outdoor temperatures ranged from 7 °C to 36 oC. House air change rates ranged from 0.26 h-1 to 0.60 h-1. Indoor temperature was relatively constant at 20 °C to 24 oC for all but one sampling event. Indoor relative humidity (RH) ranged from 21 % to 70 %. The predominant and persistent indoor VOCs included aldehydes (e.g., formaldehyde, acetaldehyde, pentanal, hexanal and nonanal) and terpene hydrocarbons (e.g., a-pinene, 3-carene and d-limonene), which are characteristic of wood product emissions. Other compounds of interest included phenol, naphthalene, and other aromatic hydrocarbons. VOC concentrations were generally typical of results reported for other new houses. Measurements of total VOCs were used to evaluate short-term changes in indoor VOC concentrations. Most of the VOCs probably derived from indoor sources. However, the wall cavity was an apparent source of acetaldehyde, toluene and xylenes and the belly space was a source of 2-butanone, lower volatility aldehydes and aromatic hydrocarbons. Indoor minus outdoor VOC concentrations varied with time. Adjusted formaldehyde concentrations exhibited the most temporal variability with concentrations ranging from 25 µg m-3 to 128 µg m-3 and the lowest concentrations occurring in winter months when indoor RH was low. A model describing the emissions of formaldehyde from urea-formaldehyde wood products as a function of temperature, RH and concentration reasonably predicted the temporal variation of formaldehyde emissions in the house. Whole-house emissions of other VOCs generally declined over the first three months and then remained relatively constant over a several month period. However, their emissions were generally lowest during the winter months. Also, an apparent association between TVOC emissions and outdoor temperature was observed on a one-week time scale.

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-53768	Year: 2003
Title: Volatile organic chemical emissions from structural insulated panel (SIP) materials and implications for indoor air quality	Published in:
Authors: Hodgson, A.T.	Type: Report
Abstract: The emissions of volatile organic compounds (VOCs) from structural insulated panel (SIP) materials were investigated. Specimens of newly produced SIPs and associated panel adhesives were obtained from two relatively large manufacturers. Additionally, specimens of the oriented strand board (OSB) used as the inner and outer sheathing and the extruded polystyrene ore for the SIP were obtained from one manufacturer. Using small-scale chambers, emissions of formaldehyde, acetaldehyde, acetic acid and other VOCs from SIPs, OSB and polystyrene were measured over a period of four months and from the adhesives over two months. SIP specimens overlaid by gypsum board panels were also tested over four months. The predominant VOCs emitted by the SIPs included acetic acid, pentanal, hexanal and styrene. The emissions of formaldehyde and acetaldehyde were relatively low. Acetic acid and the aldehydes derived from the OSB, while styrene derived from the polystyrene. One of the SIPs emitted toluene and methyl acetate. The adhesives primarily emitted a mixture of hydrocarbons. The emission rates of most VOCs from the SIP/gypsum board assemblies were approximately the same or higher than their respective emission rates from the unfinished SIPs. Modeling using VOC emission factors obtained for the SIP/gypsum board assemblies demonstrated the potential for SIP materials to degrade indoor air quality in houses. A field study to investigate VOC concentrations and emission rates in SIP houses relative to closely matched conventionally constructed houses is necessary to determine the actual impacts of SIPs. If significant impacts are observed, to it may be desirable to develop control measures to reduce the emissions of VOCs from SIPs, such as the substitution of lower emitting materials or the use of vapor diffusion barriers.

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: LBNL-47857	Year: 2002
Title: Gas-phase organics in environmental tobacco smoke: 1. Effects of smoking rate, ventilation, and furnishing level on emission factors	Published in: Environmental Science & Technology, Volume 36, Pages 846-853.
Authors: Singer, B.C., Hodgson, A., Guevarra, K.S., Hawley, E.L., Nazaroff, W.	Type: Journal Article

Report number: LBNL-47627	Year: 2002
Title: Sources of formaldehyde, other aldehydes and terpenes in a new manufactured house	Published in: Indoor Air, Volume 12, Pages 235-242.
Authors: Hodgson, A.T., Beal, D., McIlvaine, J.E.R.	Type: Journal Article
Abstract: ABSTRACT Formaldehyde, less-volatile aldehydes, and terpene hydrocarbons are generally the predominant air contaminants in new manufactured and site-built houses. This study was conducted to identify the major sources of these compounds in a typically constructed, new manufactured house. Specimens of materials used within the house envelope were collected from the production facility. These were individually preconditioned for 19 ± 4 days and tested for emissions of formaldehyde and the other target compounds using small-scale chambers. Several cabinetry materials, passage doors and the plywood subfloor were the predominant sources of formaldehyde and other aldehydes. The plywood subfloor was the predominant terpene source. Whole-house emission rates for combined materials were predicted based on the emission factors and the corresponding material quantities. These predicted rates were compared to whole-house emission rates calculated from measurements made at the house three months after its installation. For 11 of 14 target compounds including formaldehyde, the predicted and calculated rates were within a factor of two. This generally good agreement indicates that the predominant sources were correctly accounted for. Based on these results, practices are proposed for reducing the concentrations of the target compounds in newly constructed houses.

Report number: LBNL-47094	Year: 2002
Title: Predicting the emission rate of volatile organic compounds from vinyl flooring	Published in: Environmental Science & Technology, Volume 36, Pages 709-714.
Authors: Cox, S.S., Little, J.C., Hodgson, A.T.	Type: Journal Article
Abstract: A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion- controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material-phase (C0), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D). The model was verified by comparing predicted gas-phase concentrations to data obtained during small-scale chamber tests, and by comparing predicted material-phase concentrations to those measured at the conclusion of the chamber tests. Chamber tests were conducted with the VF placed top side up and bottom side up. With the exception of phenol, and within the limits of experimental precision, the mass of VOCs recovered in the gas phase balances the mass emitted from the material phase. The model parameters (C0, K, and D) were measured using procedures that were completely independent of the chamber test. Gas- and material-phase predictions compare well to the bottom-side-up chamber data. The lower emission rates for the top-side-up orientation may be explained by the presence of a low-permeability surface layer. The sink effect of the stainless steel chamber surface was shown to be negligible.

Report number: LBNL-53458	Year: 2002
Title: A fugacity-based indoor residential pesticide fate model	Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 261-266.
Authors: Bennett, D.H., Furtaw, E.J., McKone, T.E.	Type: Conference Proceedings
Abstract: Dermal and non-dietary pathways are potentially significant exposure pathways to pesticides used in residences. Exposure pathways include dermal contact with residues on surfaces, ingestion from hand- and object-to-mouth activities, and absorption of pesticides into food. A limited amount of data has been collected on pesticide concentrations in various residential compartments following an application. But models are needed to interpret this data and make predictions about other pesticides based on chemical properties. In this paper, we propose a mass-balance compartment model based on fugacity principles. We include air (both gas phase and aerosols), carpet, smooth flooring, and walls as model compartments. Pesticide concentrations on furniture and toys, and in food, are being added to the model as data becomes available. We determine the compartmental fugacity capacity and mass transfer-rate coefficient for wallboard as an example. We also present the framework and equations needed for a dynamic mass- balance model.

Report number: LBNL-47086	Year: 2001
Title: Measuring Concentrations of Volatile Organic Compounds in Vinyl Flooring	Published in: Journal of the Air & Waste Management Association, Volume 51, Pages 174-185.
Authors: Cox, S.S., Hodgson, A.T., Little, J.C.	Type: Journal Article

Report number: LBNL-43519	Year: 2000
Title: Volatile Organic Compound Concentrations and Emission Rates in New Manufactured and Site-Built Houses	Published in: Indoor Air, Volume 10, Pages 178-192.
Authors: Hodgson, A.T., Rudd, A.F., Beal, D., Chandra, S.	Type: Journal Article

Report number: LBNL-43848	Year: 1999
Title: Effect of Reversible, Diffusion-Controlled Sinks on VOC Concentrations in Buildings	Published in: Proceedings of the Indoor Air 99, Edinburgh, Scotland, Volume 5, Pages 264-269.
Authors: Zhao, D.Y., Rouques, J., Little, J.C., Hodgson, A.T.	Type: Conference Proceedings

Report number: LBNL-42704	Year: 1999
Title: Techniques for Reducing Exposures to Volatile Organic Compounds Associated with New Construction and Renovation	Published in:
Authors: Hodgson, A.T., Shimer, D.A.	Type: Report

Report number: LBNL-42703	Year: 1999
Title: Concentrations and Sources of Formaldehyde and Volatile Organic Compounds in Four New Manufactured Houses	Published in: Proceedings of the Indoor Air '99, Edinburgh, Scotland, Volume 4, Pages 119-124.
Authors: Hodgson, A.T., D. Beal, Chandra, S.	Type: Conference Proceedings

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: 1999
Title: Sorbent-coated diffusion denuders for direct measurement of gas/particle partitioning by semi-volatile organic compounds, in Advances in Environmental, Industrial and Process Control Technologies	Published in: Gas and Particle Partition Measurements of Atmospheric Organic Compounds, Volume 2, Pages 287-332.
Authors: Gundel, L.A., Lane, D.A., Lane, D.A.	Type: Book Section

Report number: LBNL-42047	Year: 1998
Title: Development of new VOC exposure metrics and their relationship to sick building syndrome symptoms	Published in: Indoor Air, Volume 8, Pages 140-152.
Authors: Ten Brinke, J., Selvin, S., Hodgson, A.T., Fisk, W.J.	Type: Journal Article

Report number: LBNL-43849	Year: 1998
Title: Indoor Air Quality Impacts of Ventilation Ducts: Ozone Removal and Emissions of Volatile Organic Compounds	Published in: Journal of Air and Waste Management Association, Volume 48, Pages 941-952.
Authors: Morrison, G.C., Nazaroff, W.W., Cano-Ruiz, A., Hodgson, A.T., Modera, M.P.	Type: Journal Article

Report number: LBL-35334	Year: 1996
Title: Characterization of volatile organic chemical emissions from carpet cushions	Published in: Journal of the Air and Waste Management Association, Volume 46, Pages 813-820.
Authors: Schaeffer, V.H., Bhooshan, B., Chen, S.B., Sonenthal, J.S., Hodgson, A.T.	Type: Journal Article

Report number:	Year: 1996
Title: A Strategy for Characterizing Homogeneous, Diffusion-Controlled, Indoor Sources and Sinks	Published in: ASTM STP 1287, Characterizing Sources of Infoor Air Pollution and Related Sink Effects, Pages 294-304.
Authors: Little, J.C., Hodgson, A.T., Tichenor, B.A.	Type: Book Section

Report number: LBL-37376	Year: 1996
Title: Use of Volatile Tracers to Determine the Contribution of Environmental Tobacco Smoke to Concentrations of Volatile Organic Compounds in Smoking Environments	Published in: Environmental International, Volume 22, Pages 295-307.
Authors: Hodgson, A.T., Daisey, J.M., Alevantis, L.E., Mahanama, K.R.R., Ten Brinke, J.	Type: Journal Article

Report number: LBL-37768	Year: 1996
Title: Factors Affecting Indoor Air Concentrations of Volatile Organic Compounds at a Site of Subsurface Gasoline Contamination	Published in: Environmental Science and Technology, Volume 30, Pages 2948-2957.
Authors: Fischer, M., Bentley, A., Bunkin, K., Hodgson, A., Nazaroff, W., Sextro, R., Daisey, J.	Type: Journal Article

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

Report number: LBL-32904	Year: 1995
Title: A Review and a Limited Comparison of Methods for Measuring Total Organic Compounds in Indoor Air	Published in: Indoor Air, Volume 5, Pages 247-257.
Authors: Hodgson, A.T.	Type: Journal Article

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