The Ro-Main No BackDraft Control is a specially designed fan cover that prevents non-filtered air and pathogens from entering buildings when the fan is not running.

A damper automatically shuts the fan cover, making an airtight seal when the fan stops running, explained Jacquelin Labrecque, the product’s inventor and part of a family who owns a 3,000-sow farm in Canada. When the fan is operating, the cover provides minimal restriction of airflow. “My family found that products were either good at sealing the fan, or letting air flow freely, but not good at both. We developed the No BackDraft Control to use negative pressure to help seal the fan.”

The cover has a fiberglass design. No electricity is required. A gear-and-spring mechanism helps close the cover tightly when the fan is not in use. When the fan is turned on, the mechanism will be reversed to help the fan open the cover. Labrecque noted the cover adapts to any type of wall fan, and can be used in filtered and unfiltered barns. The No BackDraft Control is built to withstand pressure-washer cleaning. Labrecque added that no winter cover is needed.

Leon Sheets asked if adjustments needed to be made when the cover was in the open position in order to avoid restricting the fan. Labrecque said the optimal angle for the opening the cover is 45-60 degrees.

Steve Hoff asked how much fan capacity would be lost when using the cover. Labrecque says tests have shown an air restriction of only 4%.

The No BackDraft Control has undergone testing at the University of Minnesota, where researchers concluded that the product successfully helps prevent the airborne porcine reproductive and respiratory syndrome (PRRS) virus from entering buildings through an idle fan.

“This product also has the application for fans that are set up as emergency backup fans,” Paul Yeske said.

The cost of a No BackDraft cover to fit a 48-in. fan is $900.

Learn more at www.ro-main.com.