AT THE HEART OF MOST HOMES' HEATING SYSTEMS
Know the Lingo
- Annual Fuel Utilization Efficiency (AFUE): The percentage of a fuel’s potential energy that a furnace or boiler converts to usable heat. Government standards that take effect in 2015 require AFUE levels of 82% for gas boilers, 83% for oil boilers, 80% for gas furnaces and 82% for oil furnaces.
- Air Handler: In a forced-air heating or cooling system, the air handler unit moves heated or cooled air through the home’s ductwork.
- British Thermal Unit (BTU): The unit of measurement for heat, whether it’s the heat given off by burning fuel or extracted from a home for cooling. Technically, one BTU is the energy required to raise one pound of water one degree Fahrenheit.
- Combustion Chamber: The part of a furnace or boiler where the fuel is burned.
- Compressor: That part of the air conditioner or heat pump that compresses and pumps refrigerant.
- Condenser Coil: The part of an air conditioner or heat pump that releases heat from the surrounding air in cooling mode and collects it in heating mode.
- Distribution System: The network of air ducts or hot water pipes that delivers heat from a furnace, boiler or heat pump to the home’s rooms.
- Evaporator Coil: The part of an air conditioner or heat pump that exchanges heat with the air in the home.
- Heat Exchanger: Located in the furnace or boiler, it transfers heat from the combustion chamber to the air or water in the heat distribution system.
- Heating Seasonal Performance Factor (HSPF): The heating efficiency of a heat pump. It’s a ratio of the heat it generates over the heating season, in BTUs, to the watt-hours of electricity it consumes. Heat pumps manufactured after 2006 have to have an HSPF of at least 7.7, but the best units have ratings as high as 10.
- Seasonal Energy Efficiency Ratio (SEER): The cooling efficiency of an air conditioner or heat pump. It’s the ratio of cooling output to electricity used. The minimum SEER requirement for units manufactured beginning in 2006 is 13.
- Zoning: A method of partitioning a home’s hydronic or forced-air distribution system into independently controlled comfort zones.
is a furnace, a boiler or a heat pump. A furnace burns fossil fuel to heat air that’s forced by a blower fan through a series of ducts to the living spaces; a boiler heats water that’s then pumped to a hydronic, or water-based, distribution system. Most heat pumps run on electricity. They don’t create heat, but rather extract it from the air or the ground. Heat pumps are available for use with forced-air and hydronic distribution systems. If you want to minimize your fuel bill, an Energy Star rating is a minimum standard for these appliances.