External acoustic louvre, Koolair brand, model 250-TAA (single thickness) and 250-TAAD (double thickness). Galvanized steel plate. Are used by introduction of fresh air or exhaust air discharge with attenuation of the initial noise level up to 20 dB (A) in the band of 250 Hz.
The acoustic material is glass fiber heat-resistant and protected against erosion of the air by a perforated plate on the other side of the blades. The maximum recommended temperature is 135 °C. Can incorporate bird-mesh (standard finish) or anti-insect mesh (on request).