The chimney is the engine of the wood burning stove
The chimney plays a big role when it comes to a successful wood burning stove experience. The chimney ensures complete and eco-friendly combustion.
The chimney’s most important function is to suck in enough air in the wood burning stove that you’ll get a good combustion process. If your chimney doesn’t fit your wood burning stove, you’ll get a bad chimney draught which will cause troubles when you light a fire, and there’ll be smoke in your living room, bad combustion and smoke development which will bother your neighbours.
Your chimney must be…
- Appropriately high
- Well-insulated (so the smoke won’t cool down and create tarry soot)
- Tight (check packages and clean-out door)
How to get a good chimney draught
The draught in your chimney is caused by the difference in temperature between the air and smoke inside the chimney and the outside temperature. Because of the temperature difference, an upgoing airstream will arise and it’ll get stronger the higher the chimney is and the better it’s insulated.
That’s why it can be an advantage to install a chimney which is easier to heat and which has a good insulation so it’ll keep in the heat better than a chimney made of only bricks.
The ideal chimney draught is between 12-15 pascal (Pa), but the pressure varies throughout the year. It’s highest in the winter and lowest during the summer. The draught also changes throughout the combustion process.
The wood burning stove depends on the chimney
To make the most out of your wood burning stove, it’s important that your chimney functions the way it’s supposed to. It’s important to take the height of the chimney into consideration when you place a wood burning stove and a chimney in your house.
If your house is surrounded by tall trees or buildings that’ll also play a role when it comes to deciding the height of your chimney. The wind also plays a role because it can increase or reduce the draught. There’s a risk of smoke being pushed back into the chimney and into your house, especially if the chimney isn’t higher than the ridge or if there are tall trees close by. In these instances it might be a good idea to fix an aspirotor or a chimney fan to the chimney as they will prevent the wind from blowing down the chimney.
If you have a very big chimney, it might be a good idea to install a damper in the flue. This way you can adjust the draught in the chimney and you’ll get optimal combustion. A chimney draught which is too strong can make whistling sounds from the wood burning stove and it can cause too strong combustion.
The chimney must…
- Remove the smoke from the wood burning stove and conduct it outside.
- Conduct the smoke away so it won’t bother the people who live near you.
- Draw in enough air into the wood burning stove so combustion will be clean.
Are you having problems with your wood burning stove?
If it’s difficult to light a fire or if there’s smoke in the living room when you open the stove door, it’s quite possible that your wood burning stove doesn’t meet the requirements.
One challenging aspect of this is that recently built houses are much better insulated than they were 10 years ago. New buildings are often low energy houses with ventilation systems and big cooker hoods that’ll compete about the air in the house with the chimney.
Possible solutions to a bad chimney draught
- Extend the chimney
- Make more room for air around the chimney by cutting down high trees
- Insulate or seal up cracks in the chimney
- Light a fire correctly so the temperature will rise fast
- Install a rotating chimney fan – an aspirotor
- Install a “smoke sucker” on the chimney
You can always ask your chimney sweep or contact your dealer if you have any troubles with the chimney.
