A
fireplace that allows smoke to escape into the room (back puffing) is a nuisance and a downright danger because fireplace smoke carries odorless but deadly carbon monoxide. Diagnosing the cause of your smoky fireplace is essential to finding the most efficient and cost effective solution to your back puffing.
Here's what to do if your fireplace smokes:
First, if your fireplace only smokes when you first light your fire, the solution is simple and free! You merely need to warm up your chimney's flue before you light the
fire. A convenient way to do that is to tightly roll a piece of newspaper, light one end like a torch, and hold it inside your fireplace as high as you can. Then immediately light
your fire. The pre-warmed flue will ensure the smoke goes up the flue instead of into the room.
Second, see if the fireplace is getting enough air
to replace the hot gasses it is sending up the chimney. Shut off any exhaust fans than may be running, even upstairs in your home. Those exhaust fans are pulling household air (or maybe your fireplace's smoke) to the fans. If shutting off exhaust fans doesn't stop the back puffing, test by opening a door or window near the fireplace to see if that corrects the problem. If your fireplace no longer smokes when a door or window is opened, installing an Air Supply Ventilator is the least expensive option. A pricier but sure-to-work option is installing an Exhausto Fan chimney cap for a regular flue or a round flue.
If the fireplace allows smoke to escape into your room only on windy days, the answer is to install a Vacu-Stack Chimney Cap. As the wind passes
through the Vacu-Stack chimney cap, it creates a vacuum above the flue. The harder the wind blows, the harder the Vacu-Stack "pulls" the smoke up your chimney, so all the smoke goes up
your chimney and none goes into your room.
If the smoky fireplace problem happens on calm days, too, there are three things you can do, in the order of the least expensive and the least certain to the most expensive and
absolutely certain:
If the area of your fireplace at the front (width times height in square inches) is more than ten times the area of your flue, you can install a Smoke Guard to reduce the size of the
fireplace opening. (To compute the area of your flue, if it is rectangular or square, multiply the flue's length by its width. If it is a round flue, use the radius,
which is half of the diameter. Multiply 3.14 x radius x radius.) Installing a Smoke Guard can better proportion the opening of your fireplace, allowing the flue to work more efficiently, eliminating your smoky fireplace problem. The Smoke Guards come in either brass or black.
If the second step above, increasing the air supply works, you can install an air
supply ventilator to let fresh air into the room where the fireplace is. Or you can use the Exhausto Fan solution, below.
To cure any and all back puffing problems, you can install an Exhausto Fan. An Exhausto is a weatherproof exhaust fan that mounts on the top of your chimney. These powerful
fans create a forced air draft that sucks the smoke from the flue, ending forever the problem of a smoky fireplace. Exhausto Fans can even end tricky draft problems found
with see-through fireplaces and poorly proportioned corner fireplaces. Also, count on Exhaust Fans to put an end to problem odors from your chimney.
