Rectangular acoustic silencers, Koolair brand, model PAK, PBK, PAKM and PBKM. Box of galvanized sheet steel. Designed to be installed in areas where the air distribution needs a low noise level, for the attenuation up to 50 dB(A) according to the selected model.
The acoustic material is glass fiber heat-resistant and protected against erosion by the air layer of protection against fire (PAK), if in addition it incorporates perforated plate (PBK, suitable for high speeds) or with further coating of a polyester film (PAKM and PBKM). The maximum recommended temperature is 135 °C.