What is Causing the Drafts From My Fireplace?
When a fireplace is operating as it should, there is not much to compare to the enjoyment of a fire during wintry weather. When a fireplace or wood stove is drafty, that’s a different story altogether. Not only is it unpleasant and frustrating to have smoke billowing into your home, it can also be dangerous, causing respiratory problems. If a chimney obstruction is the issue, deadly toxic fumes could even enter your living space. It can be dangerous to continue using a fireplace or wood stove when the smoke doesn’t go up the chimney. Determining the cause of your fireplace draft may require an expert, but the following are some tips that could help you solve the problem:
Cold Air in the Flue
A temporary situation that causes a chimney draft is when the air in the chimney liner is cold and won’t allow smoke to rise. A cold column of air has the effect of pushing downward toward the fireplace. When a fire is first lit, there isn’t any warmth to address an entire chimney full of cold air. What homeowners often do is create a torch with a newspaper, light it, and hold it up through the opening in the damper. Doing this once or twice is usually all it takes to dispel the cold air enough to stop the fireplace from smoking.
Wind is another potential cause of a drafty fireplace that may be temporary or may be a persistent problem caused by an ascending roof line that creates back puffing. If downdrafts are a persistent problem, adding a chimney cap could help by deflecting winds.
Negative Air Pressure
For combustion byproducts to flow up the chimney, there must be a supply of air entering the fireplace from the home. A problem that often occurs in homes with fireplaces nowadays is that the home is too tightly sealed for the chimney to perform properly. Due to negative air pressure, smoke from the fireplace will leak into the room. Another possible cause of an air flow problem, besides a sealed building envelope, is that appliances, such as kitchen exhausts, have fans exhausting air from the home. Opening a window is a simple test to determine whether negative air pressure is the cause of a drafty fireplace, but it should be considered a temporary solution.
Backdrafts can occur because of tampered air flow caused by some type of blockage or obstruction. If you have a chimney cap with mesh, there could be debris on the mesh, such as leaves or a buildup of creosote. Sometimes birds build nests in chimneys that aren’t protected by chimney caps with mesh. If the chimney liner is damaged, crumbling of the materials can occur, creating an obstruction. During a chimney cleaning, professional chimney technicians ensure that nothing is causing an obstruction. Scheduling a cleaning may be the best way to resolve this issue.
If your fireplace or wood stove vents through a stovepipe, the connector joints may be damaged or may not be fitted properly. Leakage could also be the result of deterioration.
When a fireplace and chimney system is designed properly and when an expert installs any new appliances that connect to the venting systems, everything should work fine. There are many times, however, when chimney size is causing a draft. This could be because the flue outlet on an appliance is connected to too large or too small a chimney flue or perhaps because the chimney is the wrong height for the dynamics on the rooftop.
It sometimes requires the help of a professional to determine the cause of a drafty fireplace, but the good news is that a solution can usually always be found. Contact us today if you are having problems with your fireplace or wood stove or if you would like to have professional installation of a wood-burning appliance, to avoid having a drafty fireplace.