Cleaning Glass Doors and Screens
A fireplace exhausts smoke in a sort of siphon action. Once heat begins to rise through the stack, the siphon continues to draw air from within the house. Isn't it interesting that a heat-generating devise can actually remove warm air from the home? To offset the problem, install glass doors and add outside air ducts to the inside of the firebox.
Glass doors act as dampers when the fireplace is not being used and reduce the amount of warm air that is drawn out of the home and into the fireplace when a fire has been reduced to embers.
Outside air ducts (also known as combustion air ducts) are required in the construction of all new fireplaces and can be retrofitted into existing ones. Fires burn oxygen, and in a tightly sealed home, a fireplace drains a home of oxygen in no time. Combustion air ducts provide air from the exterior of the home, leaving oxygen in the home for you to breathe. Naturally, if the fireplace draws air from ducts it won't need to draw warm air from within the home. Periodically check these ducts to make sure that they are clean and free of spider webs and other debris.