When all is well with your chimney, a fire in the fireplace or wood stove sends a continuous blast of hot gases through it that disperses into the air. A number of states can hamper this procedure, however, and the consequences — smoke pouring into the living room and inefficient heating — are uncomfortable and dangerous. Some chimney draft issues do not have easy solutions, but others do, and it is fantastic to know the difference.
Flue Size
The correct size of the chimney flue, which is the aperture through which the smoke exits, is about one-tenth the magnitude of the fireplace opening. If the flue is too small, it restricts the flow of waste gases, and when it is too big, the gases have a tendency to recirculate within the chimney rather than flowing out. You may need a chimney expert to replace the flue if it is too large, but if it is too small, the motive might simply be that it is clogged with creosote. Burning a chimney-cleaning log from the fireplace may help, but selecting a chimney sweep is a much more dependable method to clean your chimney.
Chimney Length
The length of a chimney determines its ability to produce an updraft, and the general rule is that longer is better. If the chimney rises less than a two feet above the roof and won’t form an updraft, it is probably too short — particularly if it is not straight — and lengthening it is just another job to get a chimney expert. If your chimney grows a problem with updraft that coincides with the maturation of leaf beside your residence, the branches may be restricting air circulation. If you can not cut the divisions, the solution is to increase the chimney.
Air Pressure
Air rises through the chimney when the pressure in the fireplace exceeds the pressure outdoors. When there’s no fire, or the fire is cool, the opposite condition may exist; the stress exterior may be greater than that inside. When that happens, air flows down through the chimney, which makes it difficult to initiate a fire. This is particularly common when the fireplace is at a lower ground, where the atmosphere is cooler. It’s simple to correct this problem. Simply open a door or window in the fireplace room to allow outside air into the space and equalize pressure.
Replacement Air
When a fire gets hot enough, it generates an updraft that attracts the atmosphere it needs for combustion into the fireplace. This causes a reduction of air pressure in the room, and replacing air flows in from other rooms and from outdoors. Running exhaust fans in the room while the fire burns interferes with this process and reduces the atmosphere available to the fire. You may not even know the fans are on, because they may be part of your house’s automatic heating and cooling system. Therefore, if your fire sputters if the central heat is on, then turning it away may perk up the fire.
