The measured cooling energy consumption of 52 residential buildings in different parts of the U.S. is compared with the consumption predicted by the variable-base degree-day (VBDD) method. It is found that the VBDD method correctly predicts for the group of 36 buildings with cooling requirements greater than 2 million Btu per season if a ventilation rate of 5 ach is assumed for all occupied houses. There is considerable variation on a house-by-house basis with a coefficient of variation of 0.5. The method is found to consistently overpredict the cooling consumption of buildings with measured consumption below 2 million Btu per season.

Units: I-P