Centrifugal Roof Ventilators


For centrifugal roof ventilators, NISCO is your most trusted source. The combination of experienced engineering experts and computer-controlled machinery allows us to provide products that will meet if not exceed your expectations. With 30 plus years of engineering HVAC systems, NISCO is the industry leader.

Product Design Features

At NISCO, we offer both belt- and direct-drive centrifugal roof ventilators, ranging in size from 24 to 84 inches in diameter. They provide airflow from 3,000 to 106,000 CFM up to 3/4-inch SP. However, with adjustable pitch sheaves on most of our belt-drive units, airflow becomes adjustable.

We design all units with weather-tight housing and a wide-hood overhang for optimal protection from storms. For easy maintenance, our ventilators have a pivoted hood design and a large removable panel for accessing the components, the fan, and backdraft damper, respectively.

Product Construction Features

The construction of our centrifugal roof ventilators boasts multiple features, all designed for optimal performance and reliability. To improve rigidity and extend service life, we use heavy-gauge, galvanized steel for the construction of both the base and hood. As for the finish, we apply an epoxy powder roughly 3 mils thick on parts that require a coating. We then bake the coated parts at 400 degrees Fahrenheit to achieve chemical and impact resistance.

We also manufacture the wheels to precision. Our Style H belt-drive units, which range in size from 24 to 48 inches, have six steel blades. However, our Style C drive-units with sizes between 48 and 84 inches along with our direct-drive units have adjustable pitch airfoil blades constructed of cast aluminum. These blades attach to a hub also made from cast aluminum.

Our Style H belt-drive units have a fixed shaft design combined with an integral drive/wheel hub assembly. Because the bearings are permanently lubricated and sealed, they provide 300,000 hours of L10 life. For the Style C belt-drive units, two heavy-duty pillow block ball bearings lend support to the steel fan shaft. For maximum rigidity and strength, we use heavy-gauge steel on the curb cap and support system.

Superior Quality Roof Ventilators

For professional assistance, we invite you to speak with a company representative who can provide more details about our lineup of centrifugal roof ventilators. We understand that every company has unique needs. For that reason, we never offer cookie-cutter solutions but instead, we provide you with a product tailored to your specifications.

Item Title Max CFM Max SP Max Temp
 centrifugal roof Centrifugal Roof Ventilators 35,130 3.25 180
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