EIA Report: Gas Furnace Efficiency Has Large Implications For Residential Natural Gas Use

摘要

About 40 percent of the energy delivered to the residential sector is attributed to space heating, and natural gas-and propane-fired furnaces account for almost half of that, making them a large target for potential energy efficiency gains. Yet the minimum efficiency level of gas furnaces has changed little over the past 20 years. A Department of Energy (DOE) standard that would have updated minimum gas furnace efficiency standards for the first time since 1992 has been challenged in court and delayed many times. As a result, the minimum efficiency standard for one of the highest energy-consuming residential appliance types may remain unchanged for almost three decades (see Figure 1). Gas furnaces were among the equipment types first covered by appliance standards in the National Appliance Energy Conservation Act of 1987, which set the minimum efficiency level at 78 annual fuel utilization efficiency (AFUE) starting in 1992. This rating means that it's 78 percent efficient: for 100 units of energy input, there are at least 78 units of heat output.