There are three key benefits to using fiber glass as its own duct system or as a liner or wrap in conjunction with sheet metal duct systems.
First, fiber glass duct systems or metal systems lined or wrapped with fiber glass, when properly installed and sealed, allow for minimal air leakage. This also reduces heat loss or gain. In addition, fiber glass helps ensure that air in the ducts is transmitted into each room at designed temperatures. The result? A more comfortable and efficient HVAC system that will be more economical to operate.
Second, fiber glass is a better acoustical material than metal. It absorbs noise generated by mechanical equipment and air flow. Therefore, fiber glass ducts or metal ones lined with fiber glass reduce the transmission of heating/cooling system noise through your duct system to the rooms of your home. Air rush noises are eliminated as well, resulting in quiet comfort. Fiber glass also helps reduce “cross talk”, the noise transferred from one room to another through the ducts.
Third, metal air conditioning ducts can cause moist air to condense and ducts to “sweat”. Any time the duct surface temperature is below the dew point temperature, moisture will condense and may drip and cause damage and rust. Rigid (Class 1) fiber glass air ducts help control condensation in air-conditioning duct systems.