Many people use chimneys for winter fires that help keep the cost of heating down as wood can be cheaper than other methods of heat. Unfortunately, many do not know how a chimney actually works, and this can lead to dangerous situations. It is important to know how your chimney actually works so you can take the precautions needed to stay safe.

How your chimney actually works

  • The Updraft – Chimneys are built on the updraft principle, which is a bottom to top rising airflow. If there are any breaks in the seal, there is a danger that the air can come in from areas that prevent the updraft from occurring naturally. When this happens, you could end up with a living room full of smoke or worse, a backdraft pushing the fire into the room.
  • Size Matters – There is an exact science that goes into the size and height of the chimney and how the air flows. The circumference of the chimney should be large enough to accommodate the amount of material that is burned. Conversely, the height needs to also be in proportion to the circumference of the chimney.
  • The Downdraft – When there is a crack in the chimney or when it does not extend far enough from the roof, downdrafts occur. This is caused by the air flowing across the roof that goes down into the chimney and reverses the flow of air. A clog in the chimney can also cause a downdraft, which is a sign the chimney needs cleaning.

When all three components of the chimney are working properly, there should be no smoke in the home. If smoke is ever an issue, check to see if the damper is open or if the chimney cap is being restricted. If these simple fixes are not the cause, then it is time to call in a professional to check your chimney.