What is Lack of Draught?
A lack of draught is where there is insufficient draught or upwards movement of air, fumes and smoke in a chimney.
Causes of a Lack of Draught:
Air tightness of the room or dwelling where the fireplace or stove is situated. This air tightness can be the result of double glazed windows, wall, ceiling or roof insulation, draught excluders around and under doors, no vent installed in the room where the stove or fireplace is situated.
Short chimney – longer chimneys draught better than shorter chimneys
No bend in the chimney – a bend in the correct place in the chimney can aid draught
Incorrectly sized liner in comparison to the size of the fireplace or stove. The liner must be the correct diameter for the stove or fireplace it is serving.
If there is an extractor fan or another stove or fireplace competing for the same volume of air the original stove or fireplace is using.
If the chimney liner is damaged or punctured the flue will suffer pressure loss. This must be repaired.
If two stoves / heat producing appliance is connected to the same flue – this is against Irish and British building regulations. Each stove or appliance must have its own flue.
A blockage in the chimney can cause a lack of draught. The chimney should be swept. To prevent birds from nesting in your chimney, please click here to read about the Anti Bird / Anti Rain Chimney Cowl.
If the throat of the fireplace is incorrectly formed or if there is no flue gatherer installed above the fireplace.
How it manifests:
Like a down draught, smoke can puff out from the fireplace or stove. Click here to read about a down draught.
Smoke does not rise up the chimney
If there is a smell of soot the following day the stove or fireplace has been used.
An electrical cowl must be installed with a dedicated wall vent to the outside.
For a more powerful solution than the Super C, click here to read about the Super R Electric Fan Cowl.