Although the temperatures have begun to warm up, many homeowners like to continue using their fireplaces into the spring and summer months. In order to prevent overheating, many will run their fireplaces or stoves at a low temperature. While this prevents your home from getting excessively warm, it can have unintended consequences – excessive creosote buildup.
While creosote is created by all fuel burning appliances, improperly using your fireplace or stove can cause excessive creosote buildup. This can not only impact the efficiency of your fireplace or stove, but can also affect you and your family’s safety.
What is creosote?
Creosote is a substance that is created as a byproduct of fuel burning fires. While more prevalent in heating appliances that use wood, creosote can also be created by natural gas and propane.
When your fireplace is in use, small amounts of creosote may build up in your chimney and flue. Creosote can take many forms; it may be brown or grey, fluffy or flaky, or even shiny, hard, and black if it has hardened into glazed creosote. In any of its forms, creosote is extremely flammable. Accidental ignition of creosote is the primary cause of chimney fire.
Because creosote is so flammable, creosote removal is the primary reason it is recommended that all fireplaces and stoves have their chimneys swept each year.
Causes of excessive creosote buildup
While all fuel burning fires create creosote, it is not created in equal amounts. A normal wood burning fire using seasoned firewood produces very little creosote; however, there are a number of things that can cause excessive creosote buildup.
Running stoves at low temperatures: One of the primary causes of excessive creosote buildup is running stoves at low temperatures. When the weather is mild, homeowners may use flue pipe thermometers to keep the temperature of their fire low. Without the hot air to blow the byproducts of combustion up the flue, a smoldering fire will cause them to linger in the chimney, quickly lining your flue with creosote.
Burning green wood: Because freshly cut firewood can have moisture content of as high as 50%, the fire must evaporate the water before the wood itself can burn. This causes both excessive smoke and excessive buildup of creosote.
Improperly sized flue: A flue that is too large for the fireplace can draw in too much cold air, causing the byproducts of combustion to prematurely cool on the walls of the flue. Likewise, burning a fire with restricted air flow can lead to additional creosote deposits.
Although creosote is an inevitable part of using a fuel burning appliance, there are a number of things homeowners can do to minimize the amount of creosote created. First, only seasoned firewood should be burned. Fires should not be allowed to purposefully smolder or burn at a low temperature; likewise, over firing should also be avoided. In addition, any new heating appliances such as stoves or inserts should be professionally installed in order to ensure that the flue is properly sized.
If you have questions about how creosote may be affecting the safety or efficiency of your fireplace or stove, contact The Cozy Flame today!