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Hi static / Hi pressure duct

Hi static / Hi pressure duct

Hi static / Hi pressure duct

I need to draw 3000  l/s of kitchen exhaust air through 400x400 duct up to 22 levels of a building. the pressure drop is about 600 Pa. The duct is only 1.2 mm thick galvanized steel. Can I know the problems I will have to face other than the high power required? I am not sure whether the pressure on the duct wall is too much? Can the surface of the duct (grease on the surface) get heated due to high velocity ( 19.5 m/s )
Can I use two in line fans to control the pressure up to some extent?

RE: Hi static / Hi pressure duct

Where are you in the world where you can use galvanized steel for kitchen exhaust? Generally it is required to use carbon-steel sheet with welded seams and joints.

Any chance you could increase the duct to 450x450? It would halve your static pressure losses.

600Pa (2.4") esp is high, but not exceptionally high. You're velocity is high, but the velocity pressure loss is by no means high enough to heat the duct. Identify the static pressure class and reference SMACNA duct design for the required reinforcing.

I'd be more concenred that you're moving hot, grease laden air through 22 storeys in galvanized ductwork. If you can get a copy of NFPA96 it would definetly point you in the right direction.

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