Kicking the Air Conditioner Habit

Air conditioning has become an expected feature in new California homes, even those in cooler coastal locations. Because many Californians run their air conditioners for just a few days out of the year, air conditioners use only 10%–12% of the energy in homes, yet they are responsible for about 43% of the residential peak load. This load from hell has been the bane of California utilities, and in 1994 the California Institute for Energy Efficiency (CIEE) set out to address this problem by improving the performance of production homes, of which there are about 100,000 built each year. The CIEE assembled a team of researchers to participate in a project that was dubbed Alternatives to Compressor Cooling (ACC). Continued under the California Energy Commission Public Interest Energy Research (PIER) program, the project is nearing completion. The ACC project was grounded in the idea that the need for air conditioning could be reduced or eliminated by ventilating homes with cool night air, which would cool concrete floors,walls, and other mass.This cooled mass then absorbs heat from indoor air during the day, keeping occupants comfortable enough that they avoid turning on the air conditioner or, on the hottest days, shift its use to off-peak periods. People have used ventilation to improve summer comfort for centuries. So why did the researchers feel something new was needed? Fewer people are opening windows nowadays, because they are bothered by noise from roads and freeways and by outdoor dust and pollens, or because they are worried