Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 56·4.5
Air supply for flued Decorative Fuel Effect (DFE) fires - no vent needed
A permanently open air vent is not necessary for a DFE fire if the dwelling has high air permeability, the appliance has limited heat input, and the flue gas clearance rate does not exceed specified limits.
A permanently open air vent should not be necessary for a DFE fire provided –
(a) the dwelling in which it is to be installed has an air permeability greater than 5.0 m3/hr/m2. See Appendix C;
(b) the appliance has a rated heat input not greater than 7 kW (net); and
(c) there is a flue gas clearance rate (without spilling) not greater than 70 m3/hour.
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