Hometown Heating & Cooling installed a dual-fuel system in an old schoolhouse near Sparta, Mo.

The good news for homeowners is that the National Oceanic Atmospheric Administration (NOAA) recently announced that most of the country would experience above-average temperatures and drier conditions this winter. In fact, this winter is predicted to be 2.8 percent warmer than the 30-year norm.

The bad news is that when homeowners finally do have to turn on their furnaces, they are going to see an increase in their fuel bills. The Energy Information Administration (EIA) stated that the average heating season (Oct. 1 to March 31) prices and expenditures for all space-heating fuels are projected to be higher than last year.

According to the EIA report, residential natural gas prices are expected to average $13.14 per thousand cubic feet (mcf) this winter compared with $12.36 per mcf last winter, heating oil prices are expected to average $2.88 per gallon compared with $2.48 per gallon last winter, and propane prices are expected to average $2.28 per gallon compared with $2.02 per gallon last winter. Residential electricity prices are expected to average 10.3 cents per kilowatt-hour (kWh) compared with 10.1 cents per kWh last winter.

On the bright side, the milder winter temperatures and higher fuel costs provide very good conditions for dual-fuel systems.


A dual-fuel system is basically an air-source heat pump installed with an oil, gas, or propane furnace. The system is controlled by a thermostat that determines which equipment to use based on the outside temperature. When the temperature is above 35°F or so, the heat pump warms the home as necessary; when temperatures drop below 35°, the furnace provides the heat needed to keep occupants comfortable.

For many years, International Comfort Products (ICP) has offered options that allow contractors to create dual-fuel systems by matching a split-system heat pump with a fossil fuel (natural gas, propane, or oil) fired furnace. In the past two years, the company has been expanding those options with the addition of improved electronic controls and dedicated, dual-fuel package units. All of these products are available to contractors who sell ICP brands such as Heil, Tempstar, Arcoaire, Comfortmaker, KeepRite, and Day & Night.

“ICP offers controls that enable contractors to set up dual-fuel systems by coupling any of our split-system heat pumps with any of our gas, oil, or propane furnaces,” said Mike Eberlein, product manager, heating products, ICP, Lewisburg, Tenn. “This gives them access to a full range of choices - furnace efficiencies up to 95 percent AFUE and heat pump efficiencies up to 15 SEER, and up to 9.0 HSPF. They can also choose a furnace with single- or two-stage heating and variable-speed or standard PSC [permanent split capacitance] blowers. With our dedicated dual-fuel package units, contractors can offer 13 or 14.5 SEER heat pumps with gas heating at 78 to 80 percent efficiency.”

For those who believe that dual-fuel systems work best in milder climates, it may be time to rethink that assumption. While climate can be a factor in determining the economic value of a dual-fuel system, it is not the most important factor. The key lies in comparing local costs for electricity and fossil fuel. If the local cost for electricity is relatively low in comparison to the cost of natural gas, propane, or fuel oil, dual fuel might make sense. If there is no particular savings in electricity vs. oil or gas, dual fuel is less likely to offer enough energy cost savings to offset its higher first cost.

However, one has only to look at the numbers listed earlier to see that gas and oil costs in North America are currently rising faster than electricity costs. “The net result is that dual-fuel systems are growing in popularity in both moderate and more severe winter climates - largely because electricity is a relatively good value compared with available fossil fuels,” said Eberlein.

Dual-fuel systems, such as the Tempstar PDX4 14.5 SEER packaged dual-fuel unit shown here, are gaining popularity around the country.


One company talking up the benefits of dual-fuel systems is Hometown Heating & Cooling in Sparta, Mo. This small family heating-cooling business is owned and operated by Doug Wegner and his sons, Nathan and Josh. The Wegners do a lot of residential new construction installations and say they get a lot of questions about dual-fuel systems, particularly from custom home buyers.

“Builders don’t put dual-fuel systems in spec houses, but in custom homes when we get to talk to the customers, we get a lot of questions about dual fuel, and a lot of them go with that,” said Nathan.

Recently the company had the opportunity to install a dual-fuel system consisting of a 13 SEER Arcoaire heat pump and matching gas furnace, in an historic schoolhouse near Sparta. The 100-year-old schoolhouse is in the process of being restored and is rented out for wedding receptions, reunions, and other events.

The building’s added-on utility room housed the indoor HVAC mechanical equipment, so the installation did not affect the main, historic part of the building, except for the return air vent and distribution vents in the ceiling.

The one thing they seem to like most about their new system is the fact that it’s quiet, said Doug. “They had a barbecue in back of the schoolhouse near the unit on one of the hottest days of the summer, and they commented on how quiet it was. They say the system works great, and they are really satisfied with it.”

By offering dual-fuel systems, the Wegners have differentiated themselves from their competition. Eberlein said that dual-fuel systems also offer contractors the opportunity to increase sales, as well as the profit margin on each sale. “All contractors have to do is simply present the benefits: energy savings and improved comfort. In fact, contractors have told us that dual-fuel systems, especially our package dual-fuel units, are easier to sell in areas where electricity costs are relatively low in comparison to fossil fuel costs.”

Publication date:11/19/2007