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 96,800 cfm
  • Up to 0.3 in. wg.
Purchase Options:


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.