What Is A Chimney Damper

A damper is a seal or plate that serves as a door, controlling the amount of air that enters and leaves the chimney system. It allows the flue to be opened and closed as desired. Traditionally, unwanted drafts were the main problems experienced by chimneys. Oxygen is required for effective burning of a fire and the flue permitted air to enter from outside, fueling the fire. However, when a fire was not in use, the draft blew soot and ash into the home. The damper was invented to prevent this problem by blocking the flow of air when the fire is not in use.

With the modern versions of stoves and fireplaces, there are more reasons to have a damper. When used in conjunction with an HVAC system that provides home heating and cooling, certain types of dampers prevent warm summer air from entering the home and cool air from escaping. It does the opposite during winter, keeping warm air inside and preventing cool air from entering. When the fireplace is not in use, the damper should be closed to prevent wasted energy but opened to provide oxygen when the fireplace or wood stove is being used.

Types of Chimney Dampers

The two most common kinds of dampers for a chimney system are throat and top; also known as top mount dampers.

Throat Damper

A throat damper is a steel, stainless steel, or cast iron plate that rests on tracks above a fireplace opening. It is most commonly found in an old masonry chimney, but a prefab fireplace may also feature this type of damper made from steel fashioned into a square or round shape. A prefab fireplace damper typically has a pull-down handle or left-to-right lever that opens and closes the flue. This unit is typically more efficient than the one found in a masonry fireplace.

A handle is used to operate a damper, moving the component along the tracks. At the start of the burn season, a homeowner may forget to open the fireplace damper prior to lighting a fire, which causes the home to back-fill with smoke.

Top Mount Damper

If the throat damper cannot be repaired, a top mount damper may be installed. This style may feature a rain cap and animal guard as well. It rests on the top of the flue where the cap is typically positioned. A stainless steel cable featuring a bracket that locks inside the firebox is used to operate the unit. The user simply pulls the cable to close the damper, with the locking bracket keeping the area closed. The cable is released to spring open the damper. Some experts recommend top dampers over throat dampers because the first type provides a tighter seal.

To get more heat from a fire, consider installing a heat reflector. If you would like to schedule your appointment for damper, heat reflector, and refractory panel installation, please contact us at 317-596-0200 to schedule your appointment or just go here and fill out our form.


We also sell and service wood-burning stoves, so our list of chimney and vent services just keeps getting better!