The portable damage control ventilating sets specified herein are intended to be used for damage control purposes only aboard Navy ships.

Class 0-½A and 0-½D fans, available in a single size, are rated at 500 ft³/min at 2.5 inches water gauge static pressure. They are used with ventilation hose and fittings, which may be attached to the fan inlet or outlet. Exterior surfaces of fans and fittings are of aluminum to avoid sparking when bumped against steel bulkheads. They are vaneaxial fans driven with electrical motors that have explosionproof enclosures.

Class 0-¾T fans, available in a single size, are rated at 750 ft³/min and 3.0 inches water gauge static pressure. They are used with ventilation hose and fittings, which may be attached to the fan inlet or outlet. Exterior surfaces of fans and fittings are of aluminum to avoid sparking when bumped against steel bulkheads. They are air-turbine driven centrifugal fans.