HOme made spray booth fan question

[Timmythekid]

I thought I would throw together a spray booth to practice with my new airbrush until the weather improves enough to take the show outside. Starting with the plans on Starshipmodeller for the spray booth made out of a plastic tote, I was gleefully skipping down the aisles in Canadian Tire grabbing bits and pieces of the recipe when I came to the bathroom fan. Wait a second - there are different kinds of bathroom fans now? Outrageous. So which to choose? Slightly defeated, I put everything back, came home started researching, and came across a purported formula for determining how many CFM I need to look for. Cool, okay, so, based on the size of my box, I need 250 CFM. And....bathroom fans are all generally rated 50, 70, 90 CFM, so not even close. Hmmm...

So, any thoughts from anyone on what I can get away with in a box with a 20.5 inch by 17.5 inch opening?

 

[edspaged2]

That's around equivalent to what a thermatic fan for a car radiator puts out. You could probably use multiple fan setups to do the job?

 

[pandatrooper]

You don't need that much power. I just built a spray booth for myself and its 24" tall x 24" deep x 48" wide and I put a 100cfm bathroom fan in it I got from Home Depot for $37. I put a 20" x 25" furnace filter on top of the extractor fan and vented the exhaust outside. Works great.

 

[Duncanator]

Yah! I've thrown together emergency spray booths using a cardboard box and a squirrel cage fan and dryer ducting. Not a good idea for long term (fire hazard!) but they worked.

The whole idea is just getting the air flowing out. If it flows faster, great! But if it's at least drawing the fumes and overspray away it'll do in a pinch.

 

[Timmythekid]

Righty-O, thanks, gents! Brilliant - I'll look for something around the 100 range in that case. Thanks!

 

[division 6]

You may find this page of some use.
At the bottom is a discussion on fans.

 

[Timmythekid]

You may find this page of some use.
At the bottom is a discussion on fans.

Thanks - yeah, that's actually the page where I originally found the formula for determining CFM I should be shooting for