A roaring fire in your fireplace can exhaust as much as 24,000 cubic feet of air per hour. This air must be replaced with cold air from outside, which is warmed by your heating system and then exhausted through your chimney. Minimize your losses by following a few tips:

• Keep the fireplace damper closed unless a fire is going.
• When you use the fireplace, open dampers in the bottom of the firebox (if provided) or open the nearest window slightly--approximately one inch--and close doors leading into the room; lower the thermostat setting to between 50 and 55 degrees.
• Install tempered glass doors and a heat-air exchange system that blows warmed air back into the room.
• Finally, if you never use your fireplace, plug and seal the chimney flue.