All about Chimney Dampers
The damper is a large metal door usually installed in the chimney throat that is designed to provide an airtight seal when closed. The damper serves two important functions: To allow smoke to escape the chimney when the fireplace is in use; and preventing outside air, water and other debris from accumulating in the chimney when the fireplace is not being used.
Leaky Chimney Damper
Between battling the extensive heat from the fireplace and external atmospheric conditions, the damper can eventually become warped hampering its effectiveness. You may notice water leaking through when it rains, feel a draft from the fireplace or smell a musty odor even though the damper is closed. It can also become a nesting ground for small animals or rodents that find their way in the chimney through an unsealed or cracked cap.
When the damper loses its airtight grip with the chimney it needs to be repaired or replaced as soon as possible. In addition to water leaks accelerating the deterioration of brick masonry and corroding metal parts in the fireplace, air leaking through the damper also increases energy costs. In fact, it is one of the most common sources of air leaks in homes costing homeowners hundreds of dollars per year in wasted energy.
When to Replace
If you suspect a leaky damper or your home is more than twenty years old contact a chimney professional to inspect the damper. Depending on its condition, preventing leaks may be as simple as installing weather-stripping to seal the chimney damper. However, dampers that are rusted or warped will need to be replaced. In either case, the energy savings far outweighs the cost of repairing or replacing an inefficient or inoperable damper.
Top-Mounted Chimney Dampers
For even greater energy efficiency, many homeowners are replacing traditional throat dampers with more effective top mounted chimney dampers. One of the many advantages of a top mounted damper is the strong air tight seal it forms around the chimney that completely locks out any air, water and other objects from getting into the chimney. It reduces energy costs and its location on top of the crown makes it easier to maintain. This means that cooled or heated air inside the home will no longer go up the chimney when the fireplace is not being used. You will also notice a lot less noise during those windy days and a reduction in odors from the fireplace with the absence of down drafts. There are a few different styles to choose from and they are easily installed by a qualified chimney professional. So if your damper needs to be replaced, you may want to consider a top mounted chimney damper.