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 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.