Some of the fans of the BGK are made of high quality galvanized steel which is resistant to corrosion and some models are made of aluminum material to meet their performance requirements. All models have an external rotor motor with closed structure. The device is capable of handling air at max. 40ºC. It consists of high efficiency plate heat exchanger, external rotor motor plug fan, filters and control panel components. An electric heater is available as an option.