IN-91-13-1 -- Development of the Envelope Load Equation for ASHRAE Standard 90.1 PDF

Major revisions were made to simplified equations used to calculate annual heating and cooling load effects of conservation. Previous equations were not sensitive enough to variations in climate or accurate enough in trading off conservation measures such as wall U-factor and wall thermal mass. A new database of relevant variations was developed including 2,898 DOE-2 computer runs for 36 climates. A multiple-stage linear regression analysis was used to develop improved equations. Heating and cooling degree-days at two base temperatures and a solar radiation parameter were added to improve the equations' ability to predict conservation effects in a variety of climates. The revised equations provide adequate accuracy and have incorporated in the published version of ASHRAE Standard 90.1-1989.

KEYWORDS: calculating, heat load, cooling load, energy conservation, databases, climate, heating, cooling, degree days, solar radiation, accuracy, temperature, factors