Hello,

I have a box that needs to be force vented. I have a woodwork dust
extractor and I want to size the vent for 450cfm throughput.

I have no idea of the speed of the air flow with the extractor other
than it is rated at 550cfm and uses a 4" pipe.

Anyone know where I might find a formula for calculating the vent
area?

Thanks in advance.

Dave