A Smart Shoppers Guide to Heaters and Furnaces
Most homes today are heated with a forced-air furnace, heat pump or boiler. The most appropriate type depends typically on the climate and available fuel. In the Northeast, furnaces in many older homes are fueled by oil and operate with a boiler and radiators. Natural gas forced-air is more commonly used in cold climates in other parts of the country.
Where the weather does not get as cold, electric heat pumps are an efficient alternative. Here’s an overview:
Forced-air furnaces (also called heaters) operate by blowing air across a heating source. They can be fueled by natural gas, electricity or oil. Where available, gas is most popular because it’s relatively economical. Furnaces that use electricity to heat a coil are most expensive to operate and so are usually used only where gas or oil is not available. Oil forced-air furnaces require fuel deliveries by truck to a tank on the owner’s property.
Heat pumps have an outdoor unit that looks like an air conditioner, and in fact, operates like an air conditioner when in the cooling mode. When heat is called for, the heat pump’s coil absorbs heat from outside air and pressurizes the refrigerant, making it hot enough to give off heat as it passes through an indoor coil in a unit called an air handler. The heat is then blown through ducts into the house. A heat pump usually needs a source of backup heat for those times when outside air gets too cold to provide heat by pressurizing the refrigerant. The backup heat source is usually an electric coil. Still, heat pumps can produce as much as three times more heat for the money than an electric furnace, and they are much more efficient now than when they were first introduced.
Geothermal heat pumps draw their heat and cold from water that circulates through a coil buried underground. The relatively constant temperature of the water makes this one of the most efficient systems, but it’s also the most expensive to install.
Boilers work by heating water and circulating it through pipes to radiators or baseboard heaters. There are no ducts, so central air conditioning requires a separate system. Older boilers circulated steam. This hot water heating, also called hydronic heating, is quiet and comfortable. When circulated through piping installed beneath ceramic tile or wood, the entire floor surface radiates heat upward from the floor, which many people find heavenly. Electricity, gas or oil can power boilers.
