Intake Gravity Ventilators

The gravity intake ventilators are non-powered and work on pressure differential between the inside and outside of the building.



Gravity ventilators designed for intake 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.
Purchase Options:


The GRSI 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.

  • 180 to 15,200 cfm
  • Up to 0.4 in. wg.