relief duct

[opoplectic]

What is the approximately desired velocity of a relief duct in a commercial building?!

 

[ChasBean1]

If this is an exhaust duct discharging straight up, 2,600 feet per minute (fpm) to keep out rain. Typically 3,000 fpm is recommended. Going much higher can lead to excessive pressure drop at the fan outlet. ACGIH recommends 3,000 fpm to keep a good plume, to discharge contaminants safely above a building's wake.

 

[opoplectic]

thanks,

it is not exhaust, albeit it does have the same end result (air leaving the bldg)