Simplified method for predicting building energy consumption using average monthly temperatures

A new method has been developed to predict monthly building energy use using average monthly temperatures. This newly discovered procedure can be applied to simple or complex buildings and is more accurate than standard calculation procedures that use heating and cooling degree days or temperature bins. This new method for calculating energy consumption can be used to: predict total monthly energy consumption and costs for an entire campus, large commercial building, or residential home; calculate energy savings of various energy conservation measures, including control strategies; size heating and cooling equipment; compare alternative HVAC systems; compare actual weather and billing to hourly simulation results based on typical meteorological year (TMY) data; evaluate a building´s potential for heat recovery; and check for gross errors of hourly simulation results. This calculation procedure is based on the premise that a straight line results when the difference between monthly heating and cooling loads are plotted as a function of average monthly temperature. In addition, the slope of this line is equal to the building´s conduction UA and infiltration heat loss coefficients of the building when normalized on a per unit of conditioned floor area basis. While this comes as no surprise for heating loads, it applies to cooling loads as well. Adding the average solar gain and internal heat gain from lights and equipment to the difference between monthly heating and cooling loads results in a UA line that intersects the average temperature axis at the mean interior setpoint temperature of the building (70°F)