Installation. Silencers can be installed in floor standing or suspended versions by converting the feet into suspension brackets without the need for additional parts. Application. AirM SHG plate Silencers are designed to reduce aerodynamic noise generated during operation of fan sections and spreading through the ducts of ventilation and air conditioning systems. Design and materials. AirM SHG plate Silencers are available in eight sizes. Inside the casing there are from 2 to 5 sound attenuating plates depending on the size. The sound attenuation plates consist of non-combustible basalt fibre mineral wool covered with glass canvas to prevent particles from blowing out. The operating temperature range of the flowing air is -40°C to +70°C.