The applicability of energy models to occupied houses: Summer electric use in Davis

Total electricity use and cooling loads for a three month cooling season (July–September, 1980) in single-family detached houses in Davis, California, are estimated and compared with measured data. Total electricity use is estimated by predicting cooling loads and appliance electricity use using a technique approximating a relatively low cost audit program. Cooling loads are estimated using an interpolation model to simplify application of the DOE-2.1A energy use computer model. Appliance electricty use is derived from manufacturers' data, and patterns of appliance use are elicited from occupants through a survey. While reasonably accurate prediction of aggregate electricity use and cooling load for a group of houses is possible, similar accuracy for individual houses is more difficult because of variation and uncertainty in occupant behavior patterns and building parameters. We conclude that precise forecasting of individual house electricity use is unlikely, even when there are no changes in occupancy, unless impracticably expensive monitoring techniques are employed.