AMBIENT-TEMPERATURE REGRESSION-ANALYSIS FOR ESTIMATING RETROFIT SAVINGS IN COMMERCIAL BUILDINGS

This paper describes a procedure for estimating weather-adjusted retro fit savings in commercial buildings using ambient-temperature regressi on models. The selection of ambient temperature as the sole independen t regression variable is discussed. An approximate method for determin ing the uncertainty of savings and a method for identifying the data t ime scale which minimizes the uncertainty of savings are developed. Th e appropriate uses of both linear and change-point models for estimati ng savings based on expected heating and cooling relationships for com mon HVAC systems are described. A case study example illustrates the p rocedure.