Researchers have studied fireplaces to determine the amount of heat loss through a fireplace. A recent study showed that for many consumers, heating bills may be more than $500 higher per winter due to the air leakage and wasted energy caused by fireplaces.
Normally, all fireplaces have some type of damper located above the firebox used to manually regulate the amount of air, or draft, going up the chimney and how much air the fire receives. It is important to close the damper and lock in place when a fire is not burning. This helps minimize the loss of warm room air up the chimney.
If your fireplace or stove does not have a damper, commercially available products like a Draftstopper fireplace plug, flue sealer or chimney balloon can temporarily seal off the flue and stop air from escaping up the chimney, eliminating any air leaks.
For more information on wood or pellet heating systems, visit the Department of Energy website