A flange connector is a flat, rimmed fitting used to create a strong, airtight seal between the HVAC unit and the Ducted system. These connectors are often used to attach the supply air plenum to the top of Air Handlers or the discharge of a packaged unit. Because they provide a wide surface area for fastening, they reduce air leaks and ensure that 100% of the conditioned air reaches your rooms. In Mobile Home Furnaces, a floor flange is typically used to seat the unit securely over the floor duct opening. You can find various sizes of flanges and gaskets in our Accessories-Kits section. A properly installed flange prevents the unit from vibrating against the ductwork, which keeps the system running quietly. For Commercial HVAC applications, heavy-gauge steel flanges are the standard for high-pressure systems. They are the essential structural "glue" that holds the air distribution system together.