Multi-Stage Furnaces

Multi-stage furnaces are best but expensive

The latest industry trend is multi-stage furnaces. Two-stage furnaces are most common. Jim Dulley explains, "Two-stage burners operate at either a low-heat or a high-heat output level. The low-heat output level is usually about 60 percent of the high-heat output level." In comparison, a conventional furnace cycles either on or off. A multi-stage or modulating furnace minimizes room temperature fluctuations. Dulley says this type of furnace can cost up to a thousand dollars more than a conventional furnace.

The energy savings is small, but the comfort increase is substantial. Homeowner comments in forums reflect huge satisfaction with multi-stage furnaces. Dulley says they are reliable, too. The designs have undergone considerable long-term testing. Variable-speed blowers also operate more quietly.

Chad Jones, a heating and cooling service technician in Michigan says, "A two-stage variable-speed furnace no matter what brand will save you $200 to $300 per year on just your electric bill. The variable-speed blower uses only the equivalent of a light bulb's electricity and a standard furnace uses about 600 watts of electricity when it is running. You will make your $600 back in about two to three years."