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That warm, relaxing, open fire likely is costing you a lot of money. First, firewood isn’t cheap if you need to purchase it. Second, the radiant heat may feel nice when you’re directly in front of the fire, but the already-heated air from the rest of your house is being sucked up the chimney. This makes your heat pump or furnace run longer. Third, if there’s no damper on the fireplace or the fireplace isn’t fitted with its own outdoor air source, indoor air is escaping up the chimney when the fireplace isn’t in use.

Outside air can help
Adding a source of combustion air that ducts into the fireplace can help a great deal – and it works well in combination with glass doors. The fire then will draw the air it needs for proper combustion and draft from outside, rather than conditioned air from inside. 

However, the best tip is to avoid us-ing the fireplace in extremely cold weather. All of the indoor air lost up the chimney is being replaced by cold air drawn indoors through leaks in your home’s exterior walls. During milder weather, the air leaking indoors isn’t quite as cold, so it takes less energy to warm it.

Slightly opening the closest window to the fireplace and closing the door to the room also will help, because much of the excess air being drawn up the chimney will be outdoor air from the open window. When sitting right in front of the hot fire, you probably won’t notice the chilly breeze.

Also, burn only well-seasoned wood – or no more than one unseasoned log with three seasoned ones. If you try to burn more unseasoned wood, the fire will require more combustion air to keep burning well, drawing even more air out of your home.

For safety’s sake, don’t add wood to the fire several hours before bedtime, so the fire will be out by the time you go to sleep. It’s not safe to leave a smoldering fire unattended. Also, if the fire is completely out, you can close the chimney damper to block room air loss without filling the room with smoke.

Invest in efficiency
If you make just one investment to improve the efficiency of your fire-place, it should be to install high-quality glass doors. These doors control the amount of indoor air that escapes up the chimney when a fire is burning and also when you’re not using the fireplace. 

Good fireplace doors are not inexpensive, but they’re worth the price. The best doors are relatively airtight when closed, and by adjusting combustion air vents in the bottom of the frame, you still can have a raging fire without major indoor air loss.

Keep in mind that a fire needs an adequate supply of combustion air for an efficient, clean burn. If you reduce the airflow too much, creosote buildup will occurs and enhance the potential for a chimney fire.

When your fireplace isn’t in use, insert an inflatable chimney pillow or balloon in the fireplace flue; it seals much better than the chimney damper. Once the pillow is inflated, it should stay in place. (Some models include a pole to keep it steady.)

Chimney-top dampers, which operate from indoors with a chain, also help reduce air leakage and keep critters and debris out of the chimney. It’s a good idea to hang a sign or ribbon in the fireplace to indicate that a pillow is installed or the damper is shut. This hopefully will stop someone from building a fire when the chimney is closed. 

Make the most of heat output
There are several designs of heat-circulating grates that can increase the heat output from a fireplace. Many grates are designed to fit snugly under the bottom edge of the fireplace doors and contain an electric blower that circulates indoor air through the grate, helping keep the air in the room warm.

If you decide to purchase a heat-circulating grate, select a model with a blower that has several speeds and a thermostat with an on/off switch to shut off the blower when the fire burns down. If you prefer to use the fireplace with the doors open, tubular heat-circulating grates are available to blow the heat directly out the front of the firebox. Other models have no blower and rely on natural convection.

A circulating heat exchanger with built-in glass doors also is available for a more airtight combination. In addition, some units include an optional upper oven section for cooking and baking. 

For more tips on getting the most from your fireplace, check the new Home Efficiency Analysis Tool from Touchstone Energy® Cooperatives at

These companies offer fireplace efficiency products.

Battic Door
Phone: 508-320-9082

Diamond W Products
Phone: 248-652-8833

Northline Express
Phone: 866-667-8454

Phone: 800-860-6327

Stoll Fireplace Inc.
Phone: 800-421-0771

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