EBB Design is fitted with an automatic back draught shutter to prevent air entry and limit heat leakage when the extractor is not operating. Forward Curved Centrifugal Impeller To deliver high performance with a minimum noise level against high static pressure system resistance. Centrifugal fans ...
backdraught shutter flap 1 for use in conjunction with an air extractor fan is adapted to be held in a position in which it closes an air flow duct 4 by a permanent magnet 5 and an armature 6 which co-operate to hold the flap in a duct closing position when the fan is inoperative....