The Right Choice:
High-Performance Energy-Efficient Gas Heating Systems

A new generation of high-efficiency gas heating systems is now available, with energy-saving features and designs that can mean saving as much as a third of your heating bill. These new high-efficiency furnaces and boilers are designed to cut your energy costs by increasing the amount of heat obtained from every Btu of fuel consumed.

Natural gas heating systems provide air from the registers at a temperature range that is significantly higher than normal body temperatures, so your home will feel warm and comfortable. Electric heat pumps provide air from the registers at a temperature range that is near - or sometimes below - body temperatures, which by comparison feels cool.

Natural gas heating systems allow you to heat only the rooms you choose. You can close off and not heat unused rooms in your home which saves money. Thermostats can be set back by 10 degrees at night, which can save you up to 10 percent on your annual heating bills. New high-efficiency gas heating systems provide you with the most economical, dependable and comfortable home heating.

Here are some factors to consider if you want to make the Right Choice:

Q. What terms should I know when choosing a new gas furnace?

A. Annual Fuel Utilization Efficiency (AFUE)- AFUE measures average annual seasonal efficiency of a gas furnace or boiler and may be expressed as total heating output divided by total energy (fuel) input. AFUEs for furnaces can range from 57 to 97 percent.

Automatic Vent Damper- A device installed in the venting system after the draft hood of an applicance that automatically closes the vent when the furnace or boiler is off and restricts heated air from going up the vent.

Energy Savings Payback (ESP)- The time needed to recover the investment on a conservation measure through the resulting savings on fuel.

Flue Gases- The normal products of the combustion process are carbon dioxide and water vapor which are vented into the outdoor atmosphere.

Forced Draft System- A mechanical system that moves the flue gases through the appliance and creates more efficient heat transfer in the heat exchanger.

Heat Exchanger- A section of the furnace or boiler where the heat generated by the combustion process is transferred to the circulating air or water.

Intermittent Ignition Device (IID)- Use of a spark or other source of ignition as opposed to a continuously burning pilot flame.

Secondary Heat Exchanger- An additional heat exchanger through which hot flue gases pass after leaving the conventional heat exchanger-resulting in greater efficiency.

Through-the-Wall Vent- A heating system that allows furnaces to be vented directly through the wall.

Q. How can I determine the proper size furnace for my home?

A. The size of the furnace or boiler refers to the heating capacity rather than the physical dimensions. The correct furnace or boiler sizing is determined by the size, use and construction of the house, and the normal winter temperatures in the particular area of the country. A qualified gas heating contractor should evaluate the specific needs of your home. The new equipment can then be sized correctly.

Q. What are the different gas heating systems available?

A. Conventional Warm Air Furnace- A gas burner provides heat to the heat exchanger which transfers the heat to the air that is then circulated by a blower through ducts back to the furnace through return ducts to be reheated. Equipped with standing gas pilots and draft hoods with AFUE of approximately 65 percent.

High-Efficiency Furnace or Boiler- Special efficiency features are incorporated to raise the AFUE above 78 percent. These features may include an IID, forced draft systems, improved burner, vent damper and high-efficiency heat exchanger. Other features include: horizontal and vertical models, safety controls, quiet operation, easy access, low emission burners, and long life heat exchangers.

Pulse Combustion Boiler or Furnace- Rather than at a burner, the combustion process takes place in a sealed chamber. The ignition of gas and air takes place at a rate of about 50 to 70 times per second and results in hot gases being forced into a heat exchanger which heats water or air. Combustion air comes from outside the home, and the low-temperature flue gases are vented directly outside through a small plastic pipe. A drain removes the moisture resulting from the extraction of heat by condensing water vapor. AFUE's of over 90 percent are achieved with this innovative design.

Heat Pipe High-Efficiency Furnace- The heat exchanger is a sealed tube containing a fluid. When heated, the vaporized fluid rises and carries heat to the other end of the heat pipe. The furnace's blower transfers this heat into the air that warms your home. When vapor cools, it condenses and returns to the lower end of heat pipe and cycle is repeated.

Condensing Furnace- A recuperative heat exchanger is added to condense the water vapor in the hot flue gases and extract heat. This raises the AFUE to over 90 percent. The condensed water is disposed of through a drain.

Heat Transfer Module (HTM) and Water Heating System- A module heats and distributes a glycol/distilled water solution that is transported to the indoor air duct system, where it heats the air that is ducted to the house. When the temperature of the water in the water heater drops below the preset temperature, the hot solution is automatically diverted to a heat exchanger coil in the water heater to raise the temperature of the water in the tank. This design provides and AFUE up to 94 percent.

Combination Space/Water Heating-A new heating concept utilizing a water heater as a single energy source which heats the home and at the same time provides hot water. These energy-efficient systems are designed primarily for use as a forced air heating system, but they can also be adapted for new hydronic baseboard installations. Conventional water heaters are most commonly used, but direct vent water heaters may also be utilized which allow the additional advantage of horizontal venting through an outside wall. The water used for forced air system is piped from the water heater to a heat exchanger. The fan in the air handling unit blows air across the heat exchanger forcing heated air through the ductwork into the living spaces. Hot water for domestic use is piped separately from the water heater to kitchens, laundry rooms, bathrooms or wherever it is needed.

Q. How can I interpret EnergyGuide labels?

A. The federal government requires that new furnaces and boilers be tested using DOE test procedures to allow you to compare efficiency ratings. An EnergyGuide is produced from these tests that gives the Annual Fuel Utilization Efficiency for each unit tested. Ask your local heating contractor for the EnergyGuide on the models he has available. It will give you the proper information to compare the costs of operating each type of equipment. The following illustration is an example of an EnergyGuide:

A.G.A. Design Certification

When shopping for your new gas heating system, always be sure the models you are considering are Design Certified by the American Gas Association (in the United States), Canadian Gas Association (in Canada) or another nationally recognized laboratory. In 1993, the American Gas Association and Canadian Gas Association formed a joint venture called "International Approval Services" as a means of helping to ensure that the design of gas appliances sold in these two countries meet appropriate national standards.

Make the Right Choice...
Choose Natural Gas
America's Best Energy Value.