A key design objective of modern residential, commercial and industrial facilities is to incorporate a concern for energy consumption, as well as occupant comfort and safety. A lot of investigations about the comfort of residential buildings and industrial facilities show that the large part of the claims are due to the excessive sound level of the HVAC systems .
An incorrect design and an inadequate installation procedure are usually responsible for the generation of a unacceptable sound level. In an HVAC system, the noise is normally produced by the fans and by the turbolence of air that flows through the ducts. Due to the flexing of the metallic walls, the pressure variations of the air inside the duct produce vibrations, causing mechanical energy is to be radiated outside as sound energy.
A healthier, more productive and more attractive environment depends in large part on a well-designed and properly-insulated HVAC duct systems. Carrying air to conditioned spaces inhabited by people, sensitive equipment, or a combination of both. The advent of enhanced Indoor Air Quality (IAQ) has influenced engineers to 1) keep interior ducts free of foreign materials that bring fibers into the air stream or support mold growth, and 2) address sound reduction mechanically through deflection and other methods. However, not using interior insulation results in increased transferred noise, energy loss, and higher cost solutions.