Ventilation by mechanical systems
32.—(1)  Efficient mechanical ventilation shall be provided for each compartment in the lower between deck spaces.
(2)  When passenger compartments are ventilated by mechanical means the arrangements for the delivery and distribution of fresh air and the exhaust of vitiated air, must be not less efficient than those described in the preceding rules for the cowl system of ventilation.
(3)  At least 830 cubic feet of air per hour for each adult must be delivered under the normal conditions which would prevail at sea, with an increase of 33% in the case of compartments between the machinery casings and the ship’s side. The delivery of air in the hospitals should be at least 1,600 cubic feet of air per hour for each adult. Means shall be provided in the system to control the supply of air to hospitals and care shall be taken that the vitiated air from the hospitals and the sanitary compartments does not exhaust into other compartments but into the open air.
(4)  Where any compartment is to be ventilated by mechanical means, arrangements should be made, either by interconnecting the air ducts from two or more independent sources of supply, or by additional independent means of ventilation or otherwise, to secure a sufficient supply of air, even in the event of a breakdown of any part of the mechanical system.