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| Report number: LBNL-62446 | Year: 2008 |
| Title: Energy implications of meeting ASHRAE Standard 62.2 | Published in: Accepted for publication in ASHRAE Transactions. |
| 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: 004 |
| 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 |
| 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 |
| 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: Accepted for publication in ASHRAE Journal. |
| 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-41E | Year: 2008 |
| Title: Summary of Workshop: Barriers to Energy Efficient Residential Ventilation | Published in: |
| Authors: Sherman, M.H. | Type: Report |
| 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 |
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