EIA: “Following a court challenge that caused a previous proposal to be sent back for further analysis, the U.S. Department of Energy (DOE) has issued a new proposed rulemaking to increase the minimum efficiency standards for gas furnaces, which are mostly fueled by natural gas but also include propane furnaces. Gas furnaces are one of the largest energy consumers in the residential sector, accounting for about one-fifth of the energy delivered to homes and apartments in the United States. The proposed standard would increase the minimum efficiency standard for these furnaces for the first time since 1992. As discussed in a previous Today in Energy article, gas furnaces were one of the first products covered by federal appliance standards. The first standard, enacted by Congress in 1987 and made effective starting in 1992, established the minimum efficiency level of furnaces at 78 annual fuel utilization efficiency (AFUE), meaning 78 units of heat output for every 100 units of energy input…Going from a minimum efficiency level of 78 to 92 AFUE would eliminate noncondensing gas furnaces from the marketplace. Condensing furnaces are able to obtain higher efficiencies by reusing some of the heat that would be vented out of the home through the chimney by a noncondensing furnace. Because of the changes in the way a condensing furnace exhausts, installing a condensing furnace can require additional installation or equipment switching costs. DOE’s reevaluation of the proposed standard includes more extensive analysis on equipment installation and switching costs.”