Solid Fuel Ventilation
All heating appliances that produce heat from the combustion of carbon based fuels such as gas, oil and solid fuels including wood stoves, require enough fresh air from outside for complete combustion and to enable the flue/chimney to function correctly to remove the combustion products safely to the outside.
Do I Need A Vent?
Solid Fuel, Wood and Biomass burning Appliances that draw their combustion air from within the dwelling are required by Building Regulations to have installed a fixed permanently open ventilator to provide this air from the outside of the dwelling. Without adequate ventilation there is a danger that the combustion process will be incomplete producing large amounts of carbon monoxide and also that the function of the flue will be impaired. This combination can cause emissions of poisonous gases to the room resulting in sickness and ultimately death to the occupants.
What Happens If I Don’t Have Ventilation?
There are a number of scenarios that may happen if you don’t have a vent or adequate ventilation to the room that your fire, stove or appliance is operating in.
- Your stove or appliance smoke/gases will draw back into the room
- The vents on your appliances will not operate correctly
- Danger of carbon monoxide poisoning
- Loss of efficiency from your stove, chimney or appliance
Does it not defeat the purpose of heating a house?
No! From the obvious reasons for a healthy lifestyle you still need fresh air to circulate around dwellings.
One of the main three ingredients for any fire is oxygen! Without a source of air the fire will not light properly, and the chimney will have no means of drawing heated gases up as there is no air being drawn in at the bottom.
Most Stoves and appliance actually need air flow to travel over, under and around them to transfer their heat.
How do I Know if I need a vent?
- Firstly – if you don’t have one.
- If you notice that there is no draw on your appliance, especially on calms days.
- If you find that smoke is continually coming into the room.
- If you find that there is a strong draft under your doors (especially from the hall).
- If you find that it is difficult to close the door of the room, as if there is a spring or pressure on it the last inch or so before the door is fully closed.
- If you find when closing a door or a window a puff a smoke is coming back into the room at that moment.
- If you find alarms are continuously going off near or around the appliance.
- If you find that when using your tumble dryer or extractor fan it causes problems with appliance.
My house is drafty enough, there is vents in the windows!
Each solid fuel burning appliance requires a certain amount of airflow to function correctly. This amount is either specified by the manufacturer, or guidelines are set out in the building regulations (to be complied with). Having a drafty house and windows with vents isn’t a means for fueling the fire.
You will need have a proper vent installed in the room of the appliance to the required size specifications! This however does not mean you have to put it over the other side of the room, or behind the seating area. A well planned vent for a room with an appliance or fireplace can be placed to cause no disruptions or draughts when properly installed.
Outside Air Kits
If your stove or appliance has been fitted with an Out Side Air (O.S.A) kit in a dwelling, it is recommend to install a secondary air vent in case the O.S.A kit fails or becomes clogged. In such a cases of failure or blockage the stove or appliance may cause combustion gases to return into the dwellings.
Heat Recovery Ventilation
Where an appliance or stove is to be installed in a dwelling with a Heat Recovery Ventilation (HRV), a secondary vent should be installed.
Should for example the delivery fan in the HRV unit fail, and the extraction fan in the HRV fan continues to run, the HRV may create a room pressure ‘less than atmospheric’ this low pressure will affect the flue pressure which is required to safely evacuate the produced gases of combustion from the stove or appliance.