“8.2.1 Subject to the exceptions referred to in the second paragraph and in Clause 8.2.3, an outdoor air supply sized in accordance with Clause 8.2.2 shall be provided to either an enclosure or a structure in which appliances are installed.
Except for boilers, water heaters and pool heaters that include a finned-tube heat exchanger, an outdoor air supply shall not be required in structures built before 1986 where the doors and windows of that structure have not been replaced after 1985 and the volume of the enclosure or the structure in which the appliances are installed is greater than 50 cubic feet per 1,000 Btu/h (4.84 m3 per kW) of the total input of all the appliances in the enclosure or the structure.”;