Continuing our “Case Study” trend for the year, we bring you The Tapered Duct. Tapered ducts, at all locations, present a very unique opportunity for Omni and our distributors to work our product magic. We will be discussing the original problem with the duct, our solution to the duct, and the NFPA 96 guidelines that our solution helps to make this rooftop compliant.

Below are three images of the original duct and the original grease trap tray.

This original duct violates a few NFPA 96 regulations:

  • 8.2.1 Rooftop termination shall be arranged with or provided with the following:
    • (4) The ability to drain grease out of any traps or low points formed in the fan or duct near the termination of the system into a collection container that is noncombustible, closed, rainproof, and structurally sound for the service to which it is applied and that will not sustain combustion.
  • 1.1.1 – Approved upblast fans with motors surrounded by the airstream shall be hinged, supplied with flexible weatherproof electrical cable and service hold-open retainers, and listed for this use.

Our goal is to help our customers stay safe and compliant. With this particular case study, we are still fitting the solutions onto this duct; however, we have seen this exact issue before and have pictures demonstrating what will be done to get this duct up to code.

First, we need to add a hinge as this duct is lacking one. As stated in NFPA 96 code all fans and motors shall be hinged. However, this tapered duct won’t take just any hinge! First, we need to add a pivot arm. A pivot arm is what allows us to attached a full hinge to all tapered ducts; in fact, you can learn more about how and why Omni uses this solution in our blog here. We chose a Quick-Fit Super Hinge in tandem with the pivot arm for this tapered duct.

To help our client meet NFPA 96 regulation, we created a custom bracket for the side of this tapered duct. This custom bracket allows us to use our SRS grease containment solution which helps give this duct the highest volume grease trap while maintaining a small area of use.

On top of this solution helping to meet NFPA 96 regulations, it also helps them meet EPA regulations. When grease is allowed to spill out over a container that has an open top, where rainwater can get it, grease has a higher chance of overflowing onto the roof. This is damaging to the establishment as repairing or replacing a roof can cost hundreds or even thousands of dollars, but if grease is allowed to enter storm drains then the EPA can hit a business with a fine of at least ten thousand dollars. However, since Omni designed our filters to be hydrophobic, they only capture grease and allow water to pass through. This is great for our clients because it means they don’t have to replace their filters so often.

Finding solutions for rooftop grease containment isn’t only our job, it’s our passion. The puzzle and excitement of being able to create solutions out of hundreds, perhaps even thousands, of options always keeps us guessing. If you have a rooftop grease containment problem that seems to have no solution, make sure to contact Omni because we guarantee that we can find a solution for your needs. No feat is too big for Omni Containment Systems!