Cutting Energy Costs with Dampers


Winter made an early appearance this year in the Chicagoland area with the first snowfall occurring on the last day of October. For Northern Illinoisans, that means putting away the shorts and sandals and exchanging them for warm coats, hats and scarves. Everyone is thinking ahead to the upcoming winter, which has been forecasted to be as bitter as the last one. Keeping warm is on everybody’s mind, and for those with a fireplace, that means lighting a fire to heat up the house. Along with keeping warm, another focus is on cutting energy costs. One way fireplace users can do this is by installing and properly using a fireplace damper.

Chimney Dampers Help Save Money - Aurora IL

The damper in a fireplace is a flap, usually made of metal or ceramic to resist high temperatures, found at the bottom or top of the flue. It opens and closes using a pull chain, handle or latch, and has a variety of functions, namely controlling the flow of air through the chimney. While many assume the damper is merely a safety function to keep the house from filling with smoke and other toxic fumes from the fire, it can also help save money on energy depending on how it is used an installed.

First, the damper helps control what is known as the draft of the chimney. The draft is the flow of air from inside the house, through the fire, and out of the chimney. It begins with the hot air of the fire rising up the chimney – because hot air is less dense than the cold outside air. This creates a pressure differential between the rising hot air and the outside cold air, which effectively “pulls” the air upward in the chimney. In turn, the air in the house is pulled into the fireplace and brings along with it more oxygen to fuel the fire. If the draft is too strong, the heat of the fire is drawn right out of the chimney and does not heat the home. On the other hand, if the draft is too weak, the fire burns colder or may even burn out, filling the house with smoke. Opening the damper to the correct width can actually help control the draft and keep the air flowing at the most efficient rate.

The damper also keeps heated air from escaping the house when the fireplace is not in use. When in the closed position, the damper seals off the home and prevents any expensive, heated air from flowing out the chimney.

The position of the damper also plays a role in the efficiency of the fire. A damper at the bottom of the flue means most of the chimney is cold, and this means the hot air takes longer to escape the chimney. This slows the draft and could even fill the house with smoke if the fire is too large initially. A damper at the top of the chimney means the flue stays around room temperature all the time, so the fire lights up hot and quickly right away, without wasting any energy or leaking any smoke.

If you have concerns about the efficiency of the damper on your fireplace, contact your local chimney expert. If you live in the southwest suburbs of Chicago, near Aurora, Illinois, contact Pozzi Chimney Sweep for a professional consultation.