Powder Spray Booth Fan CFM?

[ppwcanada]

I have been reading about several spray booth designs. I am looking to build a 7'x4'x6'. I am trying to figure out the size of fan to use. I intend on using 4 furnace filters, but don't want tooo much draft. I am not reclaiming powder...just want to keep it out of the shop and off me! I have seen booths ranging from 80CFM to over 1000. I wanted to have an idea before i bought a fan to avoid trial and error. Any opionions?

[ppwcanada]

Just to add to this...i hear that a rule of thumb is 100 cfm/sq ft of opening. So, with my 7' x 6' frontage, does that mean i need a 4200cfm fan? Sounds like i would be sucked up against a filter. I am thinking more that it is per sq foot of filter opening...so if i had 4 filters with a total filter opening of 8 sq ft, then 800 cfm would suffice. Anyone?

[Popeye]

100 cfm per sq ft of opening is about standard. That will give you 100FPM capture velocity in the opening. The best way to handle the filters is to gets specs from the manfacturer... all filter are not created equal. They can tell you recommended cfm and velocity for the different types of filters.

[ppwcanada]

Thanks Popeye!! That clears it up.