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Buying a Heater

Gas versus Electric

Gas Furnace

Where natural gas is available, a gas furnace is generally cheaper to run than an electric one. Bear in mind, however, that gas furnaces utilize a flame to burn fuel and generate toxic fumes. In a well-maintained, properly installed furnace, the fumes are contained inside the heat exchanger and exit your home through a vent. If you own or purchase a gas furnace, it is extremely important to have the unit examined once a year by a heating and air conditioning technician.

Electric Heater

Electric heaters are generally more expensive to run than gas furnaces. However, because they do not employ a flame and do not produce carbon monixide, they are a cleaner and safer source of heat.

Heat Pumps

A third option for heating your home or place of business is the purchase of a heat pump. Heat pumps provide a more uniform temperature throughout a building than traditional heaters, which produce a sudden blast of hot air each time they kick on. Another advantage of heat pumps is that they do not excessively dry out the air the way gas furnaces and standard electric heaters do. Heat pumps are more efficient and cost less to run than electric furnaces; however natural gas furnaces are generally less expensive to operate than heat pumps. One drawback to heat pumps is that very few technicians are properly trained to work on them.


Gas furnaces are classified by AFUE (Annual Fuel Utilization Efficiency) ratings. The AFUE number represents the percentage of the fuel the equipment uses which is converted to actual heat. For example, an 80 AFUE furnace converts eighty-percent of the fuel it uses to heat; the other twenty-percent of the fuel utilized is lost. The higher the AFUE rating, the less fuel a furnace will require to heat your home. Units with higher efficiency ratings are usually more expensive to purchase than those with lower ratings, but cost less to run and can save you money in the long run.

Comfort Features

Some furnaces offer additional features that provide greater comfort as well as improved efficiency.

Two-Speed Furnaces

Two-speed furnaces can run on low speed up to 90% of the time, so they are quieter, more efficient, and provide more consistant heating than single-speed furnaces. Longer operating periods translate into fewer on/off cycles, fewer drafts, and reduced temperature swings (one or two degrees as opposed to the four-degree swings common with single-speed furnaces). They also provide better air circulation which reduces air stratification (warm air rising to the ceiling and cold air settling on the floor).

Variable-Capacity Furnaces

Variable-capacity furnaces provide the ultimate combination of comfort and efficiency. In addition to the benefits of two-speed furnaces, they offer "smart" motors that monitor your home's comfort needs and automatically adjust the volume and speed of air to provide the most efficient heating.

Sound Levels

Furnaces don't have a standard sound rating system like the bel rating system used for air conditioners and heat pumps.

However, two-speed and variable-speed furnaces are typically quieter than standard single-speed models. Because they run for longer periods at lower speeds, they do not produce the frequent kick-on noise of single-speed furnaces. Some variable-capacity models provide a "ramp on" feature which gradually introduces warm air into your ducts. This reduces the creaking noises produced by ducts expanding and contracting with stronger blasts of heat.

Selecting a Contractor

Improperly installed equipment may not work correctly, may create environmental or safety hazards, and may waste your time as you wait for repair calls. Make sure that the company you use is fully licensed and insured and that it warranties its work. Below is a checklist for selecting the right contractor.