System Duct Dampers


Back Draft dampers are commonly installed in fan exhaust systems to prevent a back draft of outside air when the fan is off. The damper is either a Spring Return type for both horizontal and vertical mounting or Gravity Return used in vertical venting only. Air Pressure or "out draft" opens both types of Back Draft Dampers. These Dampers are of a flat split plate "butterfly" design. The Back Draft damper reduces energy loss and maintains pressurization of the area.

Barometric Draft Control Dampers are designed for Oil or Gas Furnace applications. Oil Furnaces use a "Single-Acting" draft control to maintain a consistent vent draft by counteracting the negative pressure changes caused by temperature and barometric pressure, as well as, wind effect. Gas Furnaces use a "Double Acting" draft control. It opens inwardly to maintain a uniform draft. It can also open outwardly to spill combustion by-products in case of blocked flues or down drafts.

Pressure Relief Dampers are used on Duct applications. Typically they are used to balance duct pressure on HVAC systems which are utilizing multiple Zone Dampers.