Fun in the Sun: Arizona Demonstration Home Reaches New Heights

IBACOS enables builders to construct high performance and high efficiency homes through the Department of Energy’s Building America Program. As part of this program, we partnered with the U.S. Army and National Renewable Energy Laboratory (NREL) to construct a demonstration home at the Yuma Proving Ground Base in Yuma, Arizona. The goal of this project was to show the Department of Defense and other government agencies how family housing units could be constructed with not only increased energy efficiency, but also more effective use of materials, improved water conservation techniques, and a design for sustainability. Construction of the home began in March of 2002 and was completed in July of 2003.The home is constructed of structural insulated panels, which offer excellent insulation as well as good air sealing. The extensive use of porches and pergolas provide excellent exterior window shading, a great benefit in the hot-dry Arizona climate. The home also uses windows with low solar heat gain coefficients, a high efficiency heat pump for heating and cooling, an energy recovery ventilator, a solar water heater, solar photovoltaic panels, fluorescent lighting, and Energy Star® appliances.NREL’s researchers have been monitoring the energy performance of the home since June of 2003 as part of the Building America Program. They have also created a computer model of the home using energy simulation software that allows them to compare the energy performance of the demo home against an architecturally identical home built using standard practices. This model indicates at least a 66% improvement from the standards of the Model Energy Code for Arizona. Overall, the home is one of the most efficient homes built as part of the Building America Program in 2003. This house incorporates numerous sustainable design strategies and qualifies for an Energy Star® rating. The projected annual energy use for the demonstration home is 7,100 kWh compared to 20,902 kWh for the standard construction home, which is a 66% energy savings. Monitoring of the home’s actual performance to date shows total energy use slightly lower than the projected rate, which means the home is even more efficient than originally thought. Half of the energy savings in the demo home come from reduced cooling energy needs. The photovoltaic solar electric system on the home has performed well during the monitoring period. From June to December 2003, the photovoltaic system produced an average of 35% of the electricity used to space condition the home. Because annual rainfall in Yuma is so low (average 3.2 in. per year), an additional goal for the demo home was to reduce indoor and outdoor water use by 50% compared to a typical production home in Arizona. The master suite bathroom and the guest bathroom are both equipped with new low-flow showerheads that are designed for lower flow than the 1994 EPA water conservation regulations, which prescribe a maximum flow rate of 2.25 gallons per minute. The bathrooms also feature low water use toilets. The Energy Star® clothes washer and dishwasher chosen for the home also contribute to the water efficiency package. The use of drought-tolerant plants in the landscape design eliminates the need for a separate outdoor irrigation system, again contributing to the water efficiency of the home. The key design features of this demonstration home have been incorporated into the 2003 Family Housing Construction Program at Yuma Proving Ground, in which 25 homes will be built. These features will also be incorporated into the 2005 and 2007 programs, essentially replacing all current housing at Yuma Proving Ground for enlisted and officer personnel with high efficiency units. These programs will make Yuma Proving Ground one of the most energy efficient bases within the Department of Defense, while affording military personnel safe, healthy, comfortable, and extremely efficient living quarters.