Top closing dampers
When closed, top-closing dampers act as a chimney cap, keeping your flue clean and free of obstructions. Top Closing Dampers also seal off the flue and reduce downdrafts and air loss. Additionally, these dampers can greatly reduce outside noise (like airplanes) so you can enjoy a more peaceful home environment. They prevent heated air loss from escaping out of your home and also stop the downdrafts while your chimney is not being used. The Dampers also prevent animals from entering and making a fur-ever home.