in depth
The
Monthly
Newsletter
on
Energy-Efficient
Housing
Vol. 31, No. 3 March 2011
IN DEPTH Turning an Energy Efficient Vision Into Reality: The IBACOS Energy Efficiency Lab Home IBACOS (see Sidebar 1), a leading source of quality and performance-focused services and research for the US homebuilding industry, and leading regional builder S&A Homes, broke ground on the Energy Efficiency Lab Home in March 2010 (see Figure 1). Selecting Pittsburgh, Pennsylvania, for both its proximity to IBACOS facilities, and for its cold climate zone, research from this Lab Home will help identify the design, construction, and financial approaches needed to drive down construction
IN TH I S IS S U E IN DEPTH Turning an Energy Efficient Vision Into Reality: The IBACOS Energy Efficiency Lab Home . . . .1
Figure 1. The IBACOS Lab Home in Pittsburgh, Pennsylvania. Photo courtesy of IBACOS and S&A Homes.
Sidebar 1: IBACOS IN DEVELOPMENT From 2D to 3D: Moving Toward a (Green?) National Building Information Modeling Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 IN BRIEF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 IN PRACTICE Building the Future: A Professional Perspective With Richard J. Sands, President of Hammerwell Incorporated . . . . . . . . . . . . . . . . 11 IN REFERENCE: Using Home Performance Assessments to Target Energy Efficiency Gaps in Existing Homes . . . . . . . . . . . . . . . . . . . . . . . . . .15
Since its foundation in 1991, IBACOS has worked toward a common goal – a homebuilding industry that delivers high performance homes that are designed and built to new standards of quality. Central to that vision is a more integrated, whole-house, systems approach to planning, designing, and constructing a home – optimizing how all the parts interrelate and perform more effectively together. To visit the company Web site, go to http://www.ibacos.com/. IBACOS uses a whole-house approach in its research, and believes strongly in collaboration. IBACOS has founded, and is the managing member of, an industrywide collaborative called the Best Practices Research Alliance. BuildIQ, sister company to IBACOS, focuses on Web-based learning for the homebuilding industry; visit http://www.buildiq.com. IBACOS believes that any home should and can be: energy efficient, durable, safe, healthy, comfortable, and environmentally responsible.
Energy Design Update®
2
costs and make very low energy homes more viable for builders. This project is funded by the U.S. Department of Energy’s Building America program. In Part 1 of this series, a general overview of the Lab Home and systems overview will be provided. Following articles contributed by IBACOS systems experts will detail specific functions and research results from the home. Over the six-year lifespan of the Lab Home, IBACOS will work in concert with its more than 40 project partners to evaluate energy-saving systems of the home against three general criteria, according to Kevin Brozyna, IBACOS’ Lab Home Project Manager:
March 2011
“Performance: We’re looking at how well the home conserves energy, while at the same time providing a healthy, safe, durable and comfortable environment for the homeowners. Hundreds of sensors will allow us to test and monitor key factors like individual system energy use, moisture management, air exchanges, indoor air quality, and water usage. “Constructability: We’re studying how to make highly energy efficient homes easier for homebuilders to produce on a large scale. We will look at material availability, the time and training required by the technologies we use, and how we can overcome the barriers that homebuilders might encounter in adding a zero energy home to their product line. “Cost: We’re examining how we can make very low energy homes more affordable to build and buy, while
Table 1. The goals and solutions to achieve a tight thermal envelope for the Lab Home. “Building Enclosure Performance Values” graphic courtesy of IBACOS. Editor: Amanda Voss Managing Editor: Vicki Dean
Publisher: Paul Gibson Designer: Chris Tankiewicz
Energy Design Update (ISSN 0741-3629) is published monthly by Aspen Publishers, 76 Ninth Avenue, New York, NY 10011. (212) 771-0600. One-year subscription costs $559. To subscribe, call 1-800-638-8437. For customer service, call 1-800-234-1660. POSTMASTER: Send address changes to Energy Design Update, Aspen Publishers, 7201 McKinney Circle, Frederick, MD 21704. Permission requests: For information on how to obtain permission to reproduce content, please go to the Aspen Publishers website at www.aspenpublishers.com/permissions. Printed in the U.S.A. © 2011 Aspen Publishers. All Rights Reserved. Purchasing reprints: For customized article reprints, please contact Wright’s Reprints at (877) 652-5295 or go to the Wright’s Reprints website at www.wrightsreprints.com. Editor’s Contact Information: Amanda Voss, Energy Design Update, 9019 Hunters Creek Street, Highlands Ranch, CO 80126, 303-663-2009, [email protected]. Energy Design Update is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional service. If legal advice or other expert assistance is required, the services of a competent professional person should be sought. —From a declaration of Principles jointly adopted by a Committee of the American Bar Association and a Committee of Publishers.
For subscriptions call 1-800-638-8437 or visit our Web site at www.aspenpublishers.com
March 2011
Energy Design Update®
also studying how much they can save homeowners on energy bills and the overall value they deliver.” As legislation drives energy efficiency standards higher and consumer expectations of home performance rise, the residential contractor needs to find ways to deliver energy efficiency at the lowest possible cost, ensuring competitiveness and profitability. Research gathered by IBACOS from the Lab Home seeks to address these questions, evaluating existing barriers, the need for system evolution, and the need to balance a home’s performance in terms of energy consumption with homeowner comfort and durability. To that end, IBACOS and its partners approached the Lab Home design and construction through a wholehouse systems perspective. Key research and collected data will focus on three areas of product-oriented solutions: (1) airtight, high R-value shells; (2) air distribution and comfort; and (3) efficient heating, cooling, and hot water. In a presentation outlining initial data on the Lab Home, presenter IBACOS’ Dave Stecher, Performance Testing and Monitoring Specialist, detailed the steps taken to research these three areas. First, the role of the thermal enclosure set the stage for home energy performance. By building an envelope that is super insulated, air tight, and durable, IBACOS predicted that the home over its life should experience reduced heating and cooling loads, as well as enhanced comfort for residents. To achieve this envelope, IBACOS set out six goals, and six matching solutions (refer to Table 1). Data gathered during construction revealed the primary efficacy of some of these strategies. Relying on housewrap as the primary air barrier meant careful installation and application. Housewrap was integrated with the second floor ceiling and foundation air barriers. Window and door openings and other penetrations were integrated with the air barrier and drainage plane. At housewrap stage, the home scored a 3.0 ACH50, where ACH50 denotes the hourly air change rate at a pressure difference of 50 Pascals between interior and exterior. ASTM E779-87, “Standard Test Method for Determining Air Leakage Rate by Fan Pressurization,” categorizes a score of 5.0 or less at ACH50 as a tight house. After sealing key locations and penetrations in the attic floor using spray foam, the home rated 0.88 ACH50. Spray foam in the bandjoists brought the rating to 0.77 ACH50. Wall cavity insulation and drywall installation lowered the reading to 0.65 ACH50. The completed Lab Home scored 0.54 ACH50, demonstrating the initial efficacy of its selected building techniques in a very tight envelope. Data on how
3
these solutions answered the bar set by the goals is being, and will continue to be, collected from the Lab Home. Additional strategies to achieve the thermal envelope included selection of best practices observed over the last few years, like staggered studs framing, thicker walls, exterior SPF foam sheathing, and blown cavity insulation. To test air distribution and comfort levels in the home, IBACOS installed three distribution systems for comparison – one standard and two experimental. The standard system is single-zone with multiple outlets, and uses high sidewall distribution. The first experimental system involves a 2-point system, using two thermostat controlled zones, with one supply location per zone. Airflows for both of the preceding systems are designed according to Manual D and J. The third distribution strategy uses PVC pipe as ductwork, in a single zone with multiple outlets, and sized according to Manual D, but with smaller capacity than Manual J load calculation. Each system will be run in the Lab Home for two weeks cyclically, and data will be collected to evaluate how uniform temperature and humidity is across the home under various weather conditions, how each system responds to extreme load conditions, and how each system responds to deep thermostat setbacks. Next under the lens is research analyzing efficient heating, cooling, and hot water. IBACOS determined that the heating and cooling system that made the most sense, a ground source heat pump, also made great sense for heating water. By combining the systems, energy was saved and equipment costs were reduced. To generate hot water, the Lab Home is using a desuperheater, which captures extra heat from the heat pump and uses it to
Figure 2. A comparison of conventional home water use against the energy usage expected from the Lab Home. Graphic courtesy of IBACOS.
For subscriptions call 1-800-638-8437 or visit our Web site at www.aspenpublishers.com
Energy Design Update®
4
March 2011
heat the water. Two different tank strategies were deployed, and data will focus on the efficiency and impact of each setup. Estimated energy usage of the Lab Home system, as compared to a standard home, can be seen in Figure 2 (see page 3). With such a tight thermal envelope, the Lab House needs are minimal for heating, cooling. For research purposes, IBACOS designed the ground source heat pump to be redundant, using both a standard deep well and runFigure 3. A diagram of the sub-slab ground heat exchanger. Graphic courtesy of IBACOS. ning heat pump coils directly underneath the house. During the first year, the and will verify whether the structure will provide Lab Home will rely solely on the sub-slab ground heat comfort. The Lab Home allows for exploration of exchanger, to assess its viability (refer to Figure 3 for a barriers from a production building perspective, diagram of the sub-slab loop). Obtained measurements and analysis of any building quality issues that may will quantify ground conditions that contribute to sucexist in very efficient homes. Test systems will also cess or failure of the system, and the ability of the system reveal breaking points for materials and market to sufficiently engage the ground below it and avoid accessibility. The ultimate goal is to create a packinteraction with the basement above it. age that has energy efficiency and cost effectiveness for both builder and buyer, and to make this vision Over the next 3–5 years, 300 sensors contained doable as soon as possible. throughout the house will collect data, allowing IBACOS and project partners to analyze every Contact information: IBACOS, 2214 Liberty Avenue, aspect of the home. Evaluations will decide whether Pittsburgh, PA 15222; (412) 765-3664 or 1-800-611-7052; selected systems are creating a durable structure, Web site: http://www.ibacos.com/.
IN DEVELOPMENT From 2D to 3D: Moving Toward a (Green?) National Building Information Modeling Standard The way structures come to life, from purchasing land to finally handing keys over to an owner, may soon undergo radical changes. Pressure is on in the industry, lead by the National Institute of Building Sciences (NIBS), to transition away from the two-dimensional thinking embodied in CAD to the multi-dimensional approach of building information modeling (BIM). In a 2007 presentation given in Washington, DC, Deke Smith, Executive Director for buildingSMART alliance™, defined BIM as a digital representation of the physical and functional characteristics
of a facility. BIM serves as a shared knowledge resource for information about a facility, and forms a reliable basis for decisions during its lifecycle from inception onward. In a presentation given January 27, 2011 through the Green Expo Building Event Series, Smith and Assisting Director Birgitta Foster (see Sidebar 2) outlined the future of BIM, and how a national building information modeling (NBIM) standard could influence energy efficiency in construction.
For subscriptions call 1-800-638-8437 or visit our Web site at www.aspenpublishers.com
Monthly
Newsletter
on
Energy-Efficient
Housing
Vol. 31, No. 3 March 2011
IN DEPTH Turning an Energy Efficient Vision Into Reality: The IBACOS Energy Efficiency Lab Home IBACOS (see Sidebar 1), a leading source of quality and performance-focused services and research for the US homebuilding industry, and leading regional builder S&A Homes, broke ground on the Energy Efficiency Lab Home in March 2010 (see Figure 1). Selecting Pittsburgh, Pennsylvania, for both its proximity to IBACOS facilities, and for its cold climate zone, research from this Lab Home will help identify the design, construction, and financial approaches needed to drive down construction
IN TH I S IS S U E IN DEPTH Turning an Energy Efficient Vision Into Reality: The IBACOS Energy Efficiency Lab Home . . . .1
Figure 1. The IBACOS Lab Home in Pittsburgh, Pennsylvania. Photo courtesy of IBACOS and S&A Homes.
Sidebar 1: IBACOS IN DEVELOPMENT From 2D to 3D: Moving Toward a (Green?) National Building Information Modeling Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 IN BRIEF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 IN PRACTICE Building the Future: A Professional Perspective With Richard J. Sands, President of Hammerwell Incorporated . . . . . . . . . . . . . . . . 11 IN REFERENCE: Using Home Performance Assessments to Target Energy Efficiency Gaps in Existing Homes . . . . . . . . . . . . . . . . . . . . . . . . . .15
Since its foundation in 1991, IBACOS has worked toward a common goal – a homebuilding industry that delivers high performance homes that are designed and built to new standards of quality. Central to that vision is a more integrated, whole-house, systems approach to planning, designing, and constructing a home – optimizing how all the parts interrelate and perform more effectively together. To visit the company Web site, go to http://www.ibacos.com/. IBACOS uses a whole-house approach in its research, and believes strongly in collaboration. IBACOS has founded, and is the managing member of, an industrywide collaborative called the Best Practices Research Alliance. BuildIQ, sister company to IBACOS, focuses on Web-based learning for the homebuilding industry; visit http://www.buildiq.com. IBACOS believes that any home should and can be: energy efficient, durable, safe, healthy, comfortable, and environmentally responsible.
Energy Design Update®
2
costs and make very low energy homes more viable for builders. This project is funded by the U.S. Department of Energy’s Building America program. In Part 1 of this series, a general overview of the Lab Home and systems overview will be provided. Following articles contributed by IBACOS systems experts will detail specific functions and research results from the home. Over the six-year lifespan of the Lab Home, IBACOS will work in concert with its more than 40 project partners to evaluate energy-saving systems of the home against three general criteria, according to Kevin Brozyna, IBACOS’ Lab Home Project Manager:
March 2011
“Performance: We’re looking at how well the home conserves energy, while at the same time providing a healthy, safe, durable and comfortable environment for the homeowners. Hundreds of sensors will allow us to test and monitor key factors like individual system energy use, moisture management, air exchanges, indoor air quality, and water usage. “Constructability: We’re studying how to make highly energy efficient homes easier for homebuilders to produce on a large scale. We will look at material availability, the time and training required by the technologies we use, and how we can overcome the barriers that homebuilders might encounter in adding a zero energy home to their product line. “Cost: We’re examining how we can make very low energy homes more affordable to build and buy, while
Table 1. The goals and solutions to achieve a tight thermal envelope for the Lab Home. “Building Enclosure Performance Values” graphic courtesy of IBACOS. Editor: Amanda Voss Managing Editor: Vicki Dean
Publisher: Paul Gibson Designer: Chris Tankiewicz
Energy Design Update (ISSN 0741-3629) is published monthly by Aspen Publishers, 76 Ninth Avenue, New York, NY 10011. (212) 771-0600. One-year subscription costs $559. To subscribe, call 1-800-638-8437. For customer service, call 1-800-234-1660. POSTMASTER: Send address changes to Energy Design Update, Aspen Publishers, 7201 McKinney Circle, Frederick, MD 21704. Permission requests: For information on how to obtain permission to reproduce content, please go to the Aspen Publishers website at www.aspenpublishers.com/permissions. Printed in the U.S.A. © 2011 Aspen Publishers. All Rights Reserved. Purchasing reprints: For customized article reprints, please contact Wright’s Reprints at (877) 652-5295 or go to the Wright’s Reprints website at www.wrightsreprints.com. Editor’s Contact Information: Amanda Voss, Energy Design Update, 9019 Hunters Creek Street, Highlands Ranch, CO 80126, 303-663-2009, [email protected]. Energy Design Update is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional service. If legal advice or other expert assistance is required, the services of a competent professional person should be sought. —From a declaration of Principles jointly adopted by a Committee of the American Bar Association and a Committee of Publishers.
For subscriptions call 1-800-638-8437 or visit our Web site at www.aspenpublishers.com
March 2011
Energy Design Update®
also studying how much they can save homeowners on energy bills and the overall value they deliver.” As legislation drives energy efficiency standards higher and consumer expectations of home performance rise, the residential contractor needs to find ways to deliver energy efficiency at the lowest possible cost, ensuring competitiveness and profitability. Research gathered by IBACOS from the Lab Home seeks to address these questions, evaluating existing barriers, the need for system evolution, and the need to balance a home’s performance in terms of energy consumption with homeowner comfort and durability. To that end, IBACOS and its partners approached the Lab Home design and construction through a wholehouse systems perspective. Key research and collected data will focus on three areas of product-oriented solutions: (1) airtight, high R-value shells; (2) air distribution and comfort; and (3) efficient heating, cooling, and hot water. In a presentation outlining initial data on the Lab Home, presenter IBACOS’ Dave Stecher, Performance Testing and Monitoring Specialist, detailed the steps taken to research these three areas. First, the role of the thermal enclosure set the stage for home energy performance. By building an envelope that is super insulated, air tight, and durable, IBACOS predicted that the home over its life should experience reduced heating and cooling loads, as well as enhanced comfort for residents. To achieve this envelope, IBACOS set out six goals, and six matching solutions (refer to Table 1). Data gathered during construction revealed the primary efficacy of some of these strategies. Relying on housewrap as the primary air barrier meant careful installation and application. Housewrap was integrated with the second floor ceiling and foundation air barriers. Window and door openings and other penetrations were integrated with the air barrier and drainage plane. At housewrap stage, the home scored a 3.0 ACH50, where ACH50 denotes the hourly air change rate at a pressure difference of 50 Pascals between interior and exterior. ASTM E779-87, “Standard Test Method for Determining Air Leakage Rate by Fan Pressurization,” categorizes a score of 5.0 or less at ACH50 as a tight house. After sealing key locations and penetrations in the attic floor using spray foam, the home rated 0.88 ACH50. Spray foam in the bandjoists brought the rating to 0.77 ACH50. Wall cavity insulation and drywall installation lowered the reading to 0.65 ACH50. The completed Lab Home scored 0.54 ACH50, demonstrating the initial efficacy of its selected building techniques in a very tight envelope. Data on how
3
these solutions answered the bar set by the goals is being, and will continue to be, collected from the Lab Home. Additional strategies to achieve the thermal envelope included selection of best practices observed over the last few years, like staggered studs framing, thicker walls, exterior SPF foam sheathing, and blown cavity insulation. To test air distribution and comfort levels in the home, IBACOS installed three distribution systems for comparison – one standard and two experimental. The standard system is single-zone with multiple outlets, and uses high sidewall distribution. The first experimental system involves a 2-point system, using two thermostat controlled zones, with one supply location per zone. Airflows for both of the preceding systems are designed according to Manual D and J. The third distribution strategy uses PVC pipe as ductwork, in a single zone with multiple outlets, and sized according to Manual D, but with smaller capacity than Manual J load calculation. Each system will be run in the Lab Home for two weeks cyclically, and data will be collected to evaluate how uniform temperature and humidity is across the home under various weather conditions, how each system responds to extreme load conditions, and how each system responds to deep thermostat setbacks. Next under the lens is research analyzing efficient heating, cooling, and hot water. IBACOS determined that the heating and cooling system that made the most sense, a ground source heat pump, also made great sense for heating water. By combining the systems, energy was saved and equipment costs were reduced. To generate hot water, the Lab Home is using a desuperheater, which captures extra heat from the heat pump and uses it to
Figure 2. A comparison of conventional home water use against the energy usage expected from the Lab Home. Graphic courtesy of IBACOS.
For subscriptions call 1-800-638-8437 or visit our Web site at www.aspenpublishers.com
Energy Design Update®
4
March 2011
heat the water. Two different tank strategies were deployed, and data will focus on the efficiency and impact of each setup. Estimated energy usage of the Lab Home system, as compared to a standard home, can be seen in Figure 2 (see page 3). With such a tight thermal envelope, the Lab House needs are minimal for heating, cooling. For research purposes, IBACOS designed the ground source heat pump to be redundant, using both a standard deep well and runFigure 3. A diagram of the sub-slab ground heat exchanger. Graphic courtesy of IBACOS. ning heat pump coils directly underneath the house. During the first year, the and will verify whether the structure will provide Lab Home will rely solely on the sub-slab ground heat comfort. The Lab Home allows for exploration of exchanger, to assess its viability (refer to Figure 3 for a barriers from a production building perspective, diagram of the sub-slab loop). Obtained measurements and analysis of any building quality issues that may will quantify ground conditions that contribute to sucexist in very efficient homes. Test systems will also cess or failure of the system, and the ability of the system reveal breaking points for materials and market to sufficiently engage the ground below it and avoid accessibility. The ultimate goal is to create a packinteraction with the basement above it. age that has energy efficiency and cost effectiveness for both builder and buyer, and to make this vision Over the next 3–5 years, 300 sensors contained doable as soon as possible. throughout the house will collect data, allowing IBACOS and project partners to analyze every Contact information: IBACOS, 2214 Liberty Avenue, aspect of the home. Evaluations will decide whether Pittsburgh, PA 15222; (412) 765-3664 or 1-800-611-7052; selected systems are creating a durable structure, Web site: http://www.ibacos.com/.
IN DEVELOPMENT From 2D to 3D: Moving Toward a (Green?) National Building Information Modeling Standard The way structures come to life, from purchasing land to finally handing keys over to an owner, may soon undergo radical changes. Pressure is on in the industry, lead by the National Institute of Building Sciences (NIBS), to transition away from the two-dimensional thinking embodied in CAD to the multi-dimensional approach of building information modeling (BIM). In a 2007 presentation given in Washington, DC, Deke Smith, Executive Director for buildingSMART alliance™, defined BIM as a digital representation of the physical and functional characteristics
of a facility. BIM serves as a shared knowledge resource for information about a facility, and forms a reliable basis for decisions during its lifecycle from inception onward. In a presentation given January 27, 2011 through the Green Expo Building Event Series, Smith and Assisting Director Birgitta Foster (see Sidebar 2) outlined the future of BIM, and how a national building information modeling (NBIM) standard could influence energy efficiency in construction.
For subscriptions call 1-800-638-8437 or visit our Web site at www.aspenpublishers.com
