Why is ventilation required?
Provide combustion air for fuel burning appliances.
Assist with the correct operation of chimney systems.
Cooling purposes of compartments.
Allow relief air for extraction systems.
Allow air change for comfort conditions.
Types of Ventilation
Purpose provided permanent combustion ventilation.
Requirements for purpose provided ventilation.
Of adequate size for purpose.
Correct routing and installation.
Non closeable / adjustable.
No insect scree or gauze.
Openings that prevent entry of a 10mm diameter ball but allow entry of a 5mm ball.
Be constructed of a suitable material to prevent damage or corrosion.
Shall be continuous and unobstructed.
Air vents across cavity walls shall
include a continuous duct across the cavity and shall not be staggered.
Where should air vents in internal walls be located.
Less than 450mm above floor level to reduce the spread of smoke in event of a fire.
what factors determine ventilation requirements?
Type of fuel.
How much permanent ventilation is required for a DFE fire up to 20kW
A dfe gas fire fitted in a fireplace without a throat e.g under a canopy requires a vent of what size.
The vent should be sized at 50% of the csa of the chimney.
What is the ventilation requirement for two dfe gas fires (up to 20kW net input) installed in the same room.
the ventilation requirement will be 200cm2 plus 35cm2 = 235cm2.
this represents 100cm2 for each fire plus adventitious air.