When selecting a heating system for your home, it is important to understand the relative efficiencies and energy costs associated with different heater types. The highest efficiency heaters are not necessarily the most economical to operate. Fuel sources and availability also play an important role in selecting a home heating system.
Furnaces and Boilers
Furnaces and boilers use electricity or fuel to heat air or water. Furnaces heat air, which then circulates through the home via duct work to heat the rooms. Boilers heat water or produce steam, which then circulates through a radiator or heats air by way of a coil. Furnace and boiler efficiency ratings are given in percentages and indicate how much of the fuel consumed is actually converted into heat. Old furnaces and boilers are only about 68 to 72 per cent efficient, while new high efficiency systems are 90 to 97 per cent efficient.
Considering only the electricity consumed by the heater as the residence, electric resistance heaters are nearly 100 per cent efficient. This number is misleading, however, because it does not consider the efficiency of generating that electricity. For this reason, and because of the price of electricity, electric resistance heaters are one of the more expensive types of heater to operate. If electricity is the only heating option, a heat pump is likely a more cost effective option.
Heat pumps run on electricity but only use a fraction of the power required for electric resistance heating. Rather than generating heat, heat pumps simply move heat from one place to another, using 30 to 40 per cent less electricity than electric resistance heaters. Standard air source heat pumps extract heat from outdoor air to heat indoor air, like a refrigerator in reverse, and can also provide air conditioning in summer. They are most effective in moderate climates where outdoor temperatures are not extreme.
Wood and Pellet Burning
Many homes still rely on wood or pellet stoves for warmth. Wood smoke contains pollutants including carbon dioxide, carbon monoxide, nitrogen oxides and particulates, which cause health concerns and contribute to air pollution. Older wood and pellet burning appliances inefficiently burn the fuel and release many pollutants. However, there are new models designed to control pollution and more completely burn the fuel. These efficient wood and pellet appliances provide clean and efficient heat, and are comparable to electric or gas.
- Missouri Department of Natural Resources: Residential Energy Efficiency - Space Heaters
- US DOE, Energy Savers: Portable Heaters
- US DOE, Energy Savers: Furnaces and Boilers
- US DOE, Energy Savers: Heat Pump Systems
- US DOE, Energy Savers: Electric Resistance Heating
- US DOE, Energy Savers: Wood and Pellet Heating