What Is a Chimney Damper?
A chimney damper opens and closes the chimney flue and is used to regulate the amount of air flowing into your fireplace. When a fire is burning, the chimney damper should be open. When the fireplace isn’t in use, the damper should be closed to prevent heating loss from inside your home.
Dampers are typically at the base of the chimney, where the chimney meets the firebox. Often there is a handle attached that allows for easy opening and closing. The damper is used to control the draft of air traveling into the chimney flue. It can also control the fire. Want a big, hot fire? Open the damper all the way. Close the damper a bit and it will calm the fire by limiting the amount of oxygen.
Don’t close the damper all the way while a fire is burning. You’ll soon have a house filled with smoke.
When you’re not using the fireplace, it’s always a good idea to keep the chimney damper closed. If the damper is open, warm air will rush up through the chimney and outside the house. This is sometimes called “chimney effect,’’ and will lower the temperature inside the home, resulting in higher heating costs. A closed damper also prevents cold outside air from entering the house.
Most dampers located at the bottom of a chimney, or throat of the chimney, have a handle at the base of the flue for easy opening and closing of the damper. Some chimneys have knobs above the firebox from which the damper can be operated.
Sometimes in older chimneys, the damper doesn’t fit perfectly over the flue, allowing unwanted air to come in and out of the home even when the damper is closed. Homeowners often put in new insulated windows or doors to attack heat loss, overlooking the fact that heat might be escaping through the poor-fitting damper. A professional chimney cleaning company can inspect your chimney and tell you if there are problems with the damper.