Relief Gravity Ventilators

Relief Gravity Ventilators

Gravity relief ventilators are non-powered and work on pressure differential between the inside and outside of the building.



Gravity ventilators designed for relief applications with natural gravity or negative pressure systems. Units feature a low-silhouette, fabra hood-style housing.

  • 0 to 109,800 cfm
  • Up to 0.35 in. wg.


The GRSR is a spun aluminum air relief roof ventilator for natural gravity or positive pressure systems. This model can mount either to a roof curb or with a flashing flange (GRSF) for quick and easy installations.

  • 230 to 18,400 cfm
  • Up to 0.4 in. wg.


The RGU gravity upblast ventilator is designed for use as a weatherproof outlet on vertical high-velocity exhaust systems.