This barometric by-pass damper is a single blade, counter balanced weighted damper that operates on air pressure in order to control the flow of by-pass air. The SPRD has an adjustable arm and weight to maintain the correct amount of pressure in the duct system.
5 to 95% non-condensing humidity
Zonefirst Static Pressure Regulating By-Pass Damper, Series: SPRD, 12 in Dia Damper, Round, 22 ga, Single Blade, Steel, Galvanized, Domestic