metal suspended ceiling / panel / acoustic / wire
Perforated metal is often used in the heating, ventilation and air conditioning industry as a diffuser to distribute air evenly, or to eliminate noise that is generated by the air handling system. Fan noise can travel through the ductwork and create unacceptable noise levels in various locations throughout the building.
Duct manufacturers create a double wall duct by placing acoustical insulation between the outer wall of galvanized metal and an inner wall of perforated galvanized metal. The perforated metal allows the noise to travel through the holes and be absorbed by the acoustical insulation. Double wall duct is usually installed close to the air handling equipment and is not typically used throughout the building. Most projects utilize 22ga galvanized metal with a 23% open area, the percentage determined to be the best for noise reduction.