You probably know that it’s important to open your chimney damper before lighting a fire and to close it when the fire is out. But did you know that dampers often don’t usually do a very effective job of fulfilling their primary purpose? Dampers are intended to prevent the air from inside your home from being pulled up and out of the chimney and to prevent downdrafts of outdoor air from invading your home. When dampers don’t work effectively, the two most problematic results are that your utility costs can increase significantly and stinky chimney smells can enter the home.
A chimney damper is located just above the fireplace at the opening into the chimney. The damper forms a metal-to-metal seal that is inefficient, even when new. In other words, a damper allows a flow of air to pass through the “seal.” After exposure to heat and moisture, a damper often becomes warped, this makes it even more ineffective. Not only does the typical damper allow air to pass through, but it can allow unpleasant odors from the chimney to enter the home.
Check Your Damper
If you’re wondering how tight a seal is created by the damper in your fireplace, you can perform some do-it-yourself tests. One way to test your damper is to entrap a dollar bill between the damper plates as you close it. If the bill slides out effortlessly, the damper is definitely allowing a lot of air to leak through. Perform the same test all the way across the damper, since it may only be leaky in one spot.
Another approach is to use burning incense or a match. If using a match, light it, blow it out, hold it up to the damper, and watch where the smoke trail from the incense or match goes. If it goes up the chimney, it’s a sign that you are losing a lot of heat up your chimney. Drafts are coming inside your home, if the smoke blows into the room.
What Studies Say About Dampers
An in-depth study on chimneys concluded that fireplace dampers are left open about 80% of the time. A home’s heated air is pulled up and out of the chimney steadily, if the damper is left open. The overall cost of cooling and heating energy costs are increased by 30% when the damper remains open after fires have gone out.
Research also shows that many people mistakenly believe dampers should be left partially closed as a way of directing more of the heat into the house instead of up the chimney. However, if the damper is not fully opened, the result is that the fire doesn’t get a sufficient amount of air to burn cleanly. Another potential result is the toxic fumes could enter the home, and the same effect can occur due to any kind of chimney obstruction.
A top-mounting chimney damper is a ground-breaking product which can make it possible to keep 100% of the temperatures from outside from getting into your home through the chimney. A stainless steel cable runs down the chimney and connects to a convenient handle that can be easily set to “Opened” or “Closed.”
If you have any questions about dampers or want to have a damaged damper replaced, contact our chimney professionals.
Northeastern Chimney, Inc.
formerly Nayaug Chimney Services, LLC
37 Cody Street, West Hartford, CT 06110