A report released by the Davis Energy Group and the California Energy Commission concluded that automatic ventilation cooling technology combined with building design provides cooling capabilities while reducing energy consumption. The report describes a fifth phase of the "Alternatives to Compression Cooling" project, launched in 1994 by the California Institute for Energy Efficiency.
In California, it has become common for builders to install air conditioners in coastal-influenced "transition" climates that only need air conditioning a few days each year.
In response, the project has produced NightBreeze, an integrated air-handling system that uses Californias' cool night air to save homeowners up to 60 percent in cooling costs.
NightBreeze includes a hot water air handler, damper and controls. The system brings outside air into the house through the damper and ventilation duct. Homeowners set the thermostat to a comfort level. If the house gets too cool, the system will stop bringing in cool air. If the house gets too warm, the air conditioning will turn on. During the winter, NightBreeze uses heat from the water heater to warm the house.
So far, NightBreeze has been installed in two demonstration homes that were monitored for over one year and has worked as expected. In addition to NightBreeze, the two homes included high-performance windows, a radiant barrier roof sheathing, 5/8-inch-thick drywall and greater than 50 percent hard surface flooring. Centex Homes built one house; Clarum Homes built the other. The home built by Clarum, which was located in a transition climate, maintained a comfortable temperature without air conditioning. The other home operated its two air conditioners a combined total of 8.9 hours during the summer of 2003. This home was built in a hot inland climate where the temperature reached over 100 degrees Fahrenheit on several occasions.
The report recommends that the state of California create programs to encourage builders to build homes
that would reduce peak load or air conditioner size, but currently these programs do not exist. Davis Energy Group is now taking inquiries for NightBreezes and should be able to fill initial orders in a couple months. They are initially targeting California, but plan to expand to other western markets in 2005. The contractor price is $2,850.
