arrow-header-indent Round Gravity Ventilators


Note: To submit electronically, download, complete and save the form to attach in an email.

Don’t settle for bad airflow, outsmart stagnant air with round gravity roof ventilators. This versatile product is designed for economic, low volume air movement to ventilate warehouses, light industrial buildings, attics, lofts and other buildings requiring gravity or relief ventilation. The volume of gravity air movement can be controlled by the adjustable damper. The damper is also effective in controlling water intrusion from wind driven rain and back draft conditions.

Standard Size
Standard round gravity ventilators are available in 12”, 20” and 24” diameter throat sizes. Other sizes up to 48” available through special orders.

Integral Dampers
The damper is supported in the open position by four strong springs and is closed by a 5’ long pull chain. Longer lengths available on request. Damper may be locked in any position by the use of an optional key type chain lock. Ventilator may be furnished without damper if desired. However, overspray or driven rain may enter the vented space. Ventilator with damper may function as a smoke exhaust vent by including a fusible link in the chain operator.

26-gauge inner and outer bands, rain shield and base assembly are assembled with four preformed baffles into a simple yet sturdy ventilating unit. This design achieves a free unobstructed flow of ventilated air.

Bird Screen
Assembly is completed by the installation of a 4 x 4 bird screen in the opening between the inner band and the rain shield to resist the entry of birds into the vent area.

Galvalume finish is standard, Polar White and other colors are available including Kynar®.

Base Design
The base is specifically designed for the final installation, with specified roof slope; either ridge or single slope, and either flat or mounted into the specified roof panel. Base and ventilating unit are furnished preassembled ready for installation. Single slope bases are mounted directly into roof panel and are placed in such a way as to prevent damming.

When ordering, please specify roof slope, base type, damper pull chain and paint color.

Request More Information

Continuous Ridge Vents

Personnel Door Canopies


Roof Access Hatches

Die Formed Flashing

Roof Curbs

Wall Fans

Low Profile Vents

CircumVENT Bad Airflow.