What is a Chimney Damper?

B. Turner

A chimney damper is a building component used in conjunction with a wood-burning fireplace. Also known as a chimney hood, the damper prevents unwanted airflow when the fireplace is not in use. Homeowners can easily operate the chimney damper when a fire is burning, then close it after each use. If a chimney damper is not built into the chimney or fireplace, it can be easily added using only simple tools.

When a chimney damper is open, smoke is free to exit the building through the chimney.
When a chimney damper is open, smoke is free to exit the building through the chimney.

When the damper is open, smoke from the fire can freely exit the home through the chimney. This prevents smoke from building up in the home, which can be a health hazard for residents. When the fireplace is not in use, the chimney damper should be tightly closed. This prevents heated or cooled air from escaping through the chimney, which helps improve the energy efficiency of the house. An efficient home not only produces less pollution, but also costs less to operate each month.

It is critical that homeowners remember to open the chimney damper before lighting a fire. If the damper remains closed, smoke will quickly build up in the home, which poses health risks to the entire family. Some users may partially open the damper in an attempt to heat the home more quickly once a fire is built. This is not only dangerous, but is rarely effective. Wood-burning fireplaces are vastly inefficient, and should be considered no more than a supplementary heating source.

The chimney damper should not be installed right at the mouth of the fireplace. Instead, it should be placed partway up the chimney so smoke has some room to gather as it passes through the damper to the outside of the home. Some dampers even sit all the way at the top of the chimney to maximize the space available for smoke to gather, and to ensure it won't backup into the room. Buyers should check to see how the damper is operated before determining where to place it within the chimney.

Dampers should not be confused with chimney caps. Caps are placed over the top of the chimney from outside. They improve energy efficiency, but are designed for homes with non-working or rarely-used fireplaces. Dampers are designed to be operable from inside the home, which means they can be opened or closed without climbing onto the roof. Some have chains or switches, while others requires users to reach up inside the chimney to open or close the damper.

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Discussion Comments


How expensive is it if you have to pay for chimney repair? We are in the market to buy a house, and I would love to have a fireplace.

Some of the older homes we were looking at that have fireplaces, look like they haven't had any work done to the chimney for a long time.

Don't they need to be cleaned out every so often too? I have never had a fireplace, so don't know that much about maintaining and repairing them.

It sounds like a gas fireplace would be a simpler way to go. I wouldn't buy a house just because of a fireplace, but admit they are a nice selling point.


It has been a long time since I have had a real wood burning fireplace. The heat from the logs was nice, but I don't miss all the work that goes along with it.

We now have a gas fireplace that I really enjoy. It is a lot less work, yet helps heat up the living room. On cold winter nights, it is always nice to have a fire going to take the chill out of the air and provide a nice atmosphere.

When we used our wood burning fireplace, I remember on cold, windy days, you could still hear the wind inside the chimney. You could tell if the chimney damper was not all the way closed. There would be slight draft, and the sound of the wind was even louder.


We have a wood burning fireplace that we use often during the cold months. This is not our primary heat source, but helps keep our heating bills lower. It also makes our house warm and inviting.

Sometimes making sure we have enough wood for the winter is a chore. It is also a lot of work. There is also mess when transporting the wood from outside to the fireplace.

Even with those disadvantages, I am not ready to give up using my wood fireplace. There has been a time or two when I have forgotten to open the fireplace chimney damper before I start the fire.

It doesn't take very long before you realize something is wrong because it gets very smoky. Once you open up the damper right away, the smoke disappears pretty quickly.

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