From furnaces to fireplaces, propane offers new ways to make any home affordably warm and comfortable year round, while protecting the environment.
The builder or contractor can choose from several types of propane furnaces to accommodate different architectural styles and floor plans: Propane-Fueled Central Furnaces, Wall Furnaces and Combo-Heaters.
Propane-Fueled Central Furnaces The most common type of central heating system is the forced-air furnace. Forced-air central furnaces, fueled by propane gas, have many features that are well suited to new construction, in particular:
Propane furnaces, even ultra-high efficiency models, have low-profile designs, so they can fit into tight spaces with height restrictions or narrow side clearances - even a closet. Many models can be installed and vented in a variety of ways, and some are even certified for zero clearance on side and back, to sit flush against walls.
Most of today's propane-fueled gas furnaces are equipped with electronic ignitions that activate the burners only when fuel is needed. This enhances safety by eliminating the need for standing pilot lights.
Minimizing Energy Demand
In addition to conserving energy with electronic ignition, propane gas furnaces are available with vent dampers. These "flapper" devices, installed in the flue, close when the heat demand has been met, trapping residual heat for circulation in the home. When heat is needed, the damper opens before the burners are ignited to allow combustion fumes to escape. Burners can only ignite when the damper is open, so energy is consumed only when heating is needed.
Direct-vent wall furnaces are very compact units that can be used to heat small homes. They are particularly appropriate for retrofitting older homes in which the extension of an existing heating system may be impractical, expensive, or impossible.
Most wall furnaces utilize sealed combustion systems housed in durable cabinetry. All combustion air is obtained from the outside, and all flue gases are vented outdoors, so homeowners don't have to worry about exhaust fumes. Propane wall furnaces are quiet and efficient, too. The noiseless burners are ignited with the simple push of a button, and the newest designs have AFUE ratings of 90 percent.
Thermostats are built in and no wiring is required, so these units are extremely flexible and easy to install. They don't use electricity, so heat will be available even during power outages.
One important development in propane gas heating systems is the emergence of combo-heaters that provide both water and space heating. This is accomplished by an air handler that captures the heat lost by the water heater and uses it to warm the house. These units can achieve up to 90 percent efficiencies for both water and central heating. Combo-heaters have proven themselves to be extremely efficient, reliable, and cost effective. And they're popular, too: more than one million have been installed in the United States since 1974 (Source: Bio-Radiant Energy, Inc.).
Combo-heaters are especially suited for new homes because of features like these:
- Units are direct vented and require no chimney
- They have completely sealed combustion chambers
- This is not only a safety feature but also allows them to be installed virtually anywhere in the home
- The life of the water heater is significantly lengthened because increased circulation of water reduces sediment build-up
Combo-heaters conserve space, sometimes using only as much space as a standard water heater.
The top five manufacturers of gas (natural gas and propane) warm air furnaces are Carrier, Goodman, Lennox, Rheem, and American Standard (Trane). According to Appliance magazine, total gas furnace sales in 2000 were 3.1 million. The average life expectancy of a gas furnace is 20 years (Appliance magazine, September 2001).
The AFUE (Annual Fuel Utilization Efficiency) rating on the manufacturer's yellow "Energy Guide Label" indicates how efficient a gas furnace or boiler is - that is, how well a furnace converts energy into usable heat. For example, an AFUE rating of 80 percent means that more than 80 percent of the heat generated in the home is usable. Higher AFUE ratings mean lower operating costs over the life of the system. Public Law No. 100-12, passed in 1987, requires that all gas furnaces manufactured after January 1, 1992, have a minimum AFUE of 78 percent. Newer technologies have raised efficiencies as high as 97 percent.