RP-233 -- Format and Methodology for Energy Budgets

Development of a widely acceptable and consistent method of calculating and presenting annual energy consumption in buildings has long been an interest of ASHRAE. Indeed, it is a first step in evaluating energy conservation measures and in determining whether estimated design energy consumption conforms to the design energy budget mandated by such codes as the federal Building Energy Performance Standards (BEPS). However, these quantities can be much more difficult to calculate than design heat loss and gain or required system capacity, since they involve the integration over the period in question of the influence of many factors which may vary greatly with time.

At this time no standard or widely accepted method exists for calculating and presenting energy consumption estimates or budgets. It was to develop such a methodology and presentation format that the present project was initiated. Specifically, the objective of RP-233 was to develop standardization of format and methodology sufficient to produce complete "Energy Budgets" for any type structure/complex of all fuel/energy consumptions by utility usage category summed on an annual basis by design criteria or actual building audit. It was intended that this be applicable to all existing or new residential, commercial, or industrial facilities. The final format was intended to provide a standard reporting means whereby realistic energy consumption estimates could be made by tabulation of design criteria for particular facilities.