Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 24·2.13
Positioning and installation of permanently open air vents
Permanently open air vents should be non-adjustable, positioned to avoid blockage, and installed to discourage occupants from sealing them. They must not be in fire-resisting walls (except external walls not shielding fuel storage) or within fireplace recesses.
A permanently open air vent should be non-adjustable and be positioned where it is unlikely to become blocked. It should be so installed that the building occupants are not provoked into sealing it against draughts or noise. It should not be positioned in a fire resisting wall other than an external wall that is not part of an external wall shielding a LPG or oil storage tank. A permanently open air vent should not be located within a fireplace recess.
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