Efficiency of appliance models on the market before and after DOE standards

Energy efficiency standards for appliances mandate that appliance manufacturers not manufacture or import models that have a test energy efficiency below a specified level after the standard effective date. Thus, appliance standards set a floor for energy efficiency. But do they also induce more significant changes in the efficiencies that manufacturers offer after the standard becomes effective? To address this question, we undertook an examination of before-standard and after-standard efficiency of models on the market for three products: (1) Refrigerators (1990, 1993, and 2001 standards); (2) Room air conditioners (1990 and 2000 standards); and (3) Gas furnaces (1992 standard).