Gas Fireplaces Offer Efficient Heating Choices

Despite today's fluctuating natural gas prices, gas fireplaces are the overwhelming choice in fireplaces, far outselling their cordwood counterparts. Natural gas fireplace inserts and free-standing stoves not only help maintain indoor air quality, keeping the home clean, but they create less outdoor pollution than wood-burning fireplaces.

Energy-conscious consumers are fueling the trend of using gas fireplaces, inserts and pellet stoves to provide zone heating for the spaces used most often. Utility bills are lower when they can turn down the thermostat on a central furnace and use the gas fireplace as a supplemental heat source. Highly efficient natural gas fireplace inserts, for example, can heat up to 1,000 square feet of living space at low cost.

Builders and remodelers discussing such options with their clients should keep the following recommendations in mind:

• For zone heating, consider only properly installed gas fireplaces, inserts and pellet appliances.
• Hearth & Home Technologies, the world's largest fireplace manufacturer, recommends only gas fireplace units and appliances that are Annual Fuel Utilization Efficiency rated. These units are tested to the same standard used to rate energy-efficient furnaces.
• Avoid masonry wood-burning fireplaces, which can lose up to 85 percent of the fire's heat through the chimney.
• For conversions from wood-burning to gas, fireplace inserts can be installed in almost any existing masonry fireplace and are available in a variety of styles and designs to match the home's decor.

Gas Fireplaces

Whether or not your client is interested in zone heating, the choice of fireplace is dictated by regional climate, the age and construction of the home as well as the amount of heat required.

Direct-vent fireplaces comprise the majority of gas fireplace sales. Air to feed the flame enters from the outside and relatively cool combustion gases are exhausted through a wall-mounted vent or can be vented through a roof. Direct-vent gas fireplaces are recommended for their efficiency; 70 percent of the heat they generate remains in the house. Direct-vent units are much easier and less expensive to install than traditional wood-burning or gas masonry units, and there's greater flexibility in placement. These units are also effective for zone heating because people absorb the radiant heat from the glass front while the firebox also heats the air in the room.

Class B vent (natural vent) conventional gas fireplaces require a through-the-roof Class B flue to carry away hot combustion gases and typically feature operable doors.

Pellet appliances are freestanding stoves or fireplace inserts that burn pellets for zone heating. The most common fuel is wood-based pellets made primarily from compressed sawdust. Pellets, developed in 1970s to use waste wood from manufacturing processes, are a highly efficient way to burn wood and can be purchased in 40-pound bags. Alternative fuels include grain and corn; some appliances are specially made to burn these commodities. One advantage of pellet fuel is the ability to lock in fuel costs at the beginning of the heating season.

Marcia Jedd is a Minneapolis-based freelance writer who frequently writes about design and construction.