Demonstration Project

For a monitored test, a NightBreeze hydronic unit was installed in a ConSol Building America project in Stockton, California. The 3,553 sq. ft. two-story house was completed in 2004. The house incorporates cooling energy efficiency measures including low-E2 windows, attic radiant barrier, buried ducts (~R-13 duct insulation), largely fluorescent lighting, and a 12 SEER 3.5 ton cooling system. The combination of energy-frugal homeowners (typical cooling set points are ~80F) and the Stockton-area climate makes it an ideal NightBreeze application. ConSol has been monitoring temperatures and equipment current draw using HOBO dataloggers since May 2004.

Results

Results from the summer months of June through September 2004 and June through July 2005 show a total of only 221 kWh of condensing unit energy consumption and 1069 kWh of air handler energy consumption. Reviewing a sample of the data suggests that on typical summer days, the NightBreeze system is able to reduce indoor temperatures from about 78.5F at the start of the cooling cycle to 72F when the system turns off in the morning. On the hottest days (>95F), the system reduces the indoor temperature from an average of 81F to 76F in the early morning. These impressive results demonstrate the value of the NightBreeze system and its ability to shift energy consumption from on-peak to off-peak periods.