Field Investigation of Energy-Efficient Homes in a Hot, Dry Climate

John Broniek and William Rittelmann, IBACOS, Inc.

Keywords

Abstract

The purpose of this field investigation was to verify the space conditioning energy performance of nine occupied homes in the community of Civano in Tucson, Arizona. Each home was evaluated against Tucson’s Sustainable Energy Standard (SES), representing a 50% energy savings for space conditioning energy relative to the CABO 1995 Model Energy Code. The homes represent a variety of low-mass construction methods including straw-bale, structural insulated panels, light-steel frame with rigid foam insulation, and wood frame with fiberglass insulation. Low emissivity windows and external shading were used extensively to minimize solar gains. Cooling system efficiencies range from 12 to 13 SEER and heating systems include heat pumps and mid-efficiency gas furnaces. Analysis results determined that the SES annual source heating and cooling energy target was met in six of the nine test homes based on measurement (and measurement-based simulation) information. Predictions made using EnergyGauge® USA simulation software), which uses U.S. Department of Energy (DOE) 2.1-E hourly simulation software and is the main energy analysis tool of the Building America Program, concurred with the monitoring assessment in all nine test house cases. The total energy use measured at each house, included energy generated (if applicable), is noted.