While fireplaces may be wonderful for setting a romantic mood, they are relatively inefficient when it comes to heating the home. On average, an operating open-wood burning fireplace can have efficiencies ranging up to 15 percent, depending upon its type and operation. However, if there is no fire and the damper is left open, a fireplace can actually have a “negative efficiency” as warm air from the house escapes through the chimney.
Wood stoves are more efficient at heating a room or home with the same amount of wood, in comparison to a fireplace. This is because a stove is closed and controlled.
Fortunately, there are ways to improve fireplace efficiency:
When a fireplace is not is use, the damper should be in the closed position. Since hot air rises, it naturally wants to escape through the chimney. Closing the damper seals off this avenue of escape.
Glass or Metal Doors or Heat Shields
Placed in front of the fireplace, these doors and shields will limit the amount of warm room air that escapes the house when the fireplace is not is use.
Doors work particularly well when a fire is burning down for the night, but the damper has to remain open to allow the smoke to vent.
While the fireplace is in operation, glass doors should remain open, since most of the warmth produced by a fireplace is in the form of radiant heat. If closed, the glass will deflect radiant heat back into the fireplace and reduce the heat output to the room.
New Fireplace Designs
Circulating fireplaces have heat circulation ducts built into the masonry fireplace. These pull air from the room, circulate it around a metal firebox and send it back, warmed, into the room.
Some of these units have built-in fans to increase the flow of air and heat. Made of metal, circulating fireplaces warm quickly and cool rapidly once the fire is extinguished.
An insert is basically a metal wood stove that slides neatly into the fireplace cavity. They are relatively easy to install, and can improve a fireplace’s efficiency. Before adding one, however, make sure to have your fireplace and chimney inspected and cleaned.
In fact, for the most energy efficiency from your fireplace or wood stove and to insure your family’s safety, have your fireplace and chimney cleaned and inspected at least once a year.