A heat exchanger bypass apparatus

摘要

A heat exchanger bypass apparatus comprising a bypass inlet (34) and a bypass outlet (36) for fluid communication with the air supply inlet (8) and the air supply outlet (18) of a ventilation unit (1) respectively. A bypass air channel (48) extends between the bypass inlet (34) and bypass outlet (36). An elongate rotatable damper (54) is located within the bypass air channel. The damper (54) is arranged to rotate about its longitudinal axis between and open and closed position in which it opens and closes the bypass air channel (48) respectively. Sealing ridges (66) are located on opposing sides of the bypass air channel (48). The ridges (66) and the rotatable damper (54) are arranged such the side edges of the damper (54) engage and sealingly abuts the sealing ridges (66) when in the closed position to close and seal the bypass air channel (48).