On Feb. 10, the U.S. Department of Energy (DOE) issued a pre-publication Federal Register notice of proposed rulemaking (NOPR) for certain residential furnaces. The proposed rule would raise the national minimum energy-efficiency standard for residential nonweatherized gas furnaces from the current 78 percent AFUE — which is set to increase to 80 percent in November — to 92 percent while also setting new efficiency standards for electrical consumption in standby mode.