12. Mechanical ventilation
(1) Every system of mechanical ventilation shall be approved by the local authority and the minimum rate of air change for airlocks and water closet, slop hopper or urinal apartments shall be 25 litres per second per fixture but in no case less than 10 air changes per hour.
(2) In every case the ventilating fan and the power unit operating it shall be in duplicate, except that single units may, with the approval of the local authority, be permitted in private dwellings where the main shaft is designed to act as an efficient natural vent in the event of the mechanical equipment failing.
(3) The system of mechanical ventilating provided shall be separate and distinct from any other system of mechanical ventilation in the building and shall be of the exhaust type.
(4) Upon completion, the owner or his representative shall carry out such tests of the ventilating system as the local authority requires.
(5) The mechanical system shall be operated continuously and maintained in good working order and condition, under the direction of a properly qualified person.
(6) Any such mechanical system shall be open to inspection by the officers of the local authority at all reasonable times and shall be subject to such tests as the local authority requires.
(7) An offence is committed whenever ¾
(a) there is any failure to comply with any of the requirements of this regulation; or
(b) the ventilating system fails, for a period longer than 48 hours, to operate continuously and efficiently.
[Regulation 12 amended in Gazette 3 May 1974 p. 1439.]