TGD J 2014 – 4.2.1 – Air supply to appliances

4.2.1 Any room or space containing an appliance (other than a room-sealed appliance) should have a permanent ventilation opening of free area of at least: – 550 mm2 per kW of rated output but in no case less than 6,500 mm2 where the air permeability is greater than 5.0m3/(h.m2), or – 6,500 mm2 + 550 mm2 per kW of rated output above 5 kW where the air permeability is less than 5.0 m3/(hr.m2). Where room-sealed appliances are contained in compartments, the compartment may require ventilation for cooling purposes (see sub-section 1.2.2). Note: It is unlikely that dwellings built prior to 2008 would have an air permeability of less than 5 m3/h/m2 at 50 Pa unless extensive air tightness measures have been carried out (see Appendix B for further guidance on airtightness of dwellings).

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