Forced ventilation for cooling attics in summer.

The potential for air conditioning energy savings using exhaust fans to cool attics was investigated in six occupied townhouses at Twin Rivers. These houses were compared with similar houses without attic fans. The houses had various levels of instrumentation. Data collected for two summer months in 1977 was the basis for this study. The principal quantities measured were attic and living space temperatures, air conditioner and attic fan usage,together with outside air temperature and solar flux. The attics with fans were substantially cooler, however the corresponding heat flux into the living space through the attic insulation is a very small part of the house air conditioning load. Any difference between the air conditioner energy use between houses with and without fans is not discernible from other factors which lead to house-to-house variation in air conditioner use.