Why Bother?

• To enable a Rayburn to operate safely and efficiently, it is necessary to ensure an adequate supply of fresh air is available into the kitchen.
• In most cases this is both mandatory and a legal requirement, to provide a combustion air supply to the fire or burner and to enable the chimney or flue system to operate.
• Power flue models do require a combustion air supply as listed below.

How?

• Provide an air-brick from the kitchen to the outside air or use a purpose built duct.
• Badly fitting windows and doors don't count.
• The size of the brick or ventilator is crucial, as is the material of which it is made.
• Air supply requirements are normally quoted as 'free air openings' i.e. the total area of all the holes, not the actual size of the brick. This amount will be quoted by the airbrick manufacturer.
• Terra Cotta or clay bricks have much smaller holes, therefore have far less 'free air' space to admit air.
• Purpose designed, plastic ventilators have greater free air space, and can therefore be of smaller dimensions.

Comparison of free area of terra cotta (bottom) and plastic brick (top) for similar size brick

Air bricks and ventilators must not be closable --- i.e. Not the 'Hit & Miss' type, or incorporate a gauze or fly screen which could become blocked.

Where?

• The air-brick should be sited as close to the Rayburn as possible, so as to minimize draught across the room and to warm the incoming air.
• Avoid a position where a cold draught is likely to be encountered.
• They must not communicate with a garage or ventilated roof space, or take air directly from a cavity wall.
• Alternatively the air supply can be brought under floor or through a duct. This can terminate in the kick-board of work units. If the vent is mounted in the floor it must be in a position where it cannot be accidentally become blocked with floor coverings.
• Window vents should be avoided to prevent a security risk.

A useful method of ducting air close to the Rayburn. Where space is restricted, air is brought in underneath the work units.

Beware!!!

Electric extractor fans and stove hoods do not count as an air supply for these regulations. Quite the reverse, they are busy sucking air out of the room.

The amount of air supply requested is a minimum. If there are other combustion appliances fitted in the same room or extractors etc, even tumble dryers, then the size of air supply must be increased accordingly. Likewise, if a flue draught stabiliser is fitted.