I just purchased a 5hp, 4 bag collector with an 8" intake and a 13.1/2" impeller diameter. I need to run about 30 feet of trunk line to drop to most of my machines. The stated useful volume airflow is 2514 cfm and the "collector inlet vacuum~in.H2O" is 5. What would be the right size trunk line in this setup? My table saw needs 1100 cfm.
(Dust Collection Forum)
From contributor B:
Go to the company you are going to buy the duct from. Give them a drawing of the layout and they will draw the trunk and drops needed to supply the machines. They have a program that does this for them. We did it on our current system and it works great.
This should easily flow well over 800 cfm to the base, with reasonable static pressure losses, and about 400 cfm to the over-arm blade cover, depending on its internal porting. The smallest internal diameter there will determine the flow.
Velocity in the main should be well above desired flow minimums. Velocity in the 7" drop would easily exceed 4000 fpm (closer to 4500 fpm).
These numbers presume that the actual performance of your dc is as stated, and whether or not you're using blast gates for the different drops, as well as the size of those other drops.