The whole building design approach evaluates the building as a complete system using energy modeling, cost data and Davis Energy Group’s past experience to evaluate combinations of energy efficiency measures and tradeoffs between building elements. DEG’s research in this area focuses both on building level optimization of energy efficiency packages alongside measure level research, evaluating measures and strategies that contribute to these goals such as advanced envelope measures that minimize heating and cooling loads, indoor air quality, and quality assessment.
In 1991, DEG was selected by PG&E to serve as the Residential Design-Build contractor under the Advanced Customer Technology Test for Maximum Energy Efficiency (ACT²) program. Directed by steering committee members Amory Lovins (RMI), Ralph Cavanaugh (NRDC), and Carl Weinberg (PG&E), the project included both existing and new buildings and paved the way for subsequent low energy projects by developing a method called “sequential analysis” that optimizes combinations of energy efficiency measures. In the development of the BEopt simulation, NREL applied similar modeling and analysis techniques. Two new homes and two retrofits were completed under the project. DEG also completed retrofit designs for and monitored one commercial office building.
The California Energy Commission’s Residential Construction Quality Assessment (RCQA) Project was initiated in 1999 to assess the performance of key energy components in new California production homes. A range of diagnostic tools including duct pressurization devices, blower doors, pressure gauges, and infrared cameras were used to evaluate construction quality employing a standardized testing and data collection process. This report covered the second of two field test phases in which 30 houses were tested throughout the state. The 30 Phase II houses were selected to assess California “leading edge” practitioners who are installing, testing and verifying tight duct systems, which the Energy Commission defines as total duct leakage of less than 6 percent of system fan flow. The Phase II houses were tested during the 2001/2002 winter. Results of this study helped inform the development of the Quality Insulation Installation (QII) program under Title 24.
In 2006-2007, DEG conducted a multi-season study for the California Air Resources Board of ventilation and indoor air quality in 108 new single-family, detached homes in California. thirty-two percent of the homes did not operate their windows and 80 percent never used the kitchen exhaust fan during the 24 hour test Day. The conclusion was that new single-family detached homes in California are built relatively tight, and when windows/doors are not opened for ventilation (e.g. for security, noise, odor, dust, thermal comfort concerns) the outdoor air exchange rates are typically low (e.g. 0.2 ach) and indoor concentrations of air contaminants with indoor sources such as formaldehyde can be significantly elevated. This study suggests that consideration should be given to installing mechanical outdoor air ventilations systems in new single-family residences to provide a dependable and continuous supply of outdoor air to the residence.
In 1998 and 2004, DEG partnered with ACEEE in developing Emerging Technology Assessments. The most recent study highlights selected technologies and practices which promise to save at least 0.25% of U.S. annual energy use by 2020; which avoid large “lost opportunities” in new construction; or which capture important regional opportunities.
Building America team lead, Alliance for Residential Building Innovation. One of 10 multidisciplinary teams chosen by the Department of Energy to deliver innovative energy efficiency strategies to the residential market, and to address barriers to bringing high-efficiency homes within reach for all Americans.