Part # STMPD (size) Round Electronic Bypass Damper for commercial systems.

Part # STCD W x H Rectangular Electronic Bypass Damper for commercial systems.

Part # 101ASPC Static Pressure Sensor to control electronic Bypass Dampers.

The Bypass Damper is a pressure relief valve placed between the supply and return ducts of the forced air duct work. As Zone dampers start closing, the bypass damper will open and divert some of the supply air to the return. This prevents a pressure buildup in the supply duct which can cause fan cavitation, excessive air velocities, and excessive zone damper blow-by.