A chimney damper is a plate or seal that works like a door to control air entering and leaving your chimney.  Dampers allow you to open or close the flue as needed.  In the olden days, the main problem chimneys had was the unwanted drafts. For a fire to burn effectively you have to have oxygen, and the flue allowed air from the outside to fuel the fire.  That’s a great thing; however, when the fire was not being used, that same draft blew ash and soot back into the kitchens.  Thus a damper was the answer. It was simply a way to block airflow when there was no need for a fire.

Jump to a more modern fireplace and stove, and there are even more reasons for a damper.  One of those is the modern HVAC systems that cool and heat your home. The damper acts as a blocker of the unwanted warm air in the summer coming in your home and also blocks cooler air from escaping out of the home and wasting energy and vice-versa in the winter. It should be closed when the fireplace is not being used.  There are two main types of dampers: throat (or bottom) dampers and top dampers.

Throat Damper sits on the tracks just above fireplace opening

Throat Dampers

A throat damper is a plate, usually made of cast iron, steel or stainless steel, that sits on tracks just above the fireplace opening.  It is operated by a handle which makes the damper move along the tracks.  The tracks usually are not easily replaceable, but the damper plates and handles can be replaced. Although these kinds of dampers are most common in old masonry chimneys, throat dampers are also found in prefab fireplaces.  In prefab fireplaces, the damper is slightly different from ones in masonry fireplaces.  Dampers in prefab fireplaces may be round or square and are made of steel.  They usually have left-to-right levers or pull-down handles to open and close the flue.  These are usually more efficient then the ones found in masonry fireplaces.  A common problem at the beginning of the burn season is that the homeowner forgets to open the damper before lighting a fire.  If this happens, the home will quickly fill up with smoke.

Top Dampers

A top damper may be used if the original throat damper is lost or cannot be fixed.  They can come with or without an animal guard and rain cap.  These dampers sit on top of the flue where the cap would be.  They are also operated by a stainless steel cable with a locking bracket inside the firebox.  To operate, pull down on the cable to close and release to open.  When you pull down, the locking bracket will hold the damper closed.  When the cable is released, the damper springs open.  Some chimney sweeps believe that these type of dampers are better than the throat dampers since they tend to give a tighter seal when closed. Contact us today!


Top damper with cage (to keep out the animals) with cap on it

Refractory Panels & Heat Reflectors are great ways get more heat from your fire. Just another great chimney application.