System Interactions and Energy Savings in a Hot Dry Climate

To evaluate opportunities for reducing cooling energy use in a hot dry climate, two new production houses located near Phoenix, Arizona, were studied: 1) a control home built with standard construction and 2) a prototype home with an integrated package of energy-saving features. The prototype's energy-saving features included spectrally selective windows, interior air handler location, low-lossducts, and high efficiency air-conditioning equipment. Both houses were monitored while unoccupied for a period of several weeks during very hot weather to evaluate cooling energy use. A comparison of short periods of detailed data showed a cooling energy use reduction of approximately 40% during peak summer conditions. Effects of the various energy-saving measures and their interactions wereseparated by a series of test that focused on specific components of the overall cooling load. It is important to understand the interactions of shell measures with mechanical system measures to properly size equipment and minimize overall system costs. An experimental technique was also developed to directly measure the contribution of window solar gains to overall cooling loads.