What CFM rating do I need?

[RaindropRising]

The fan I'm looking at to put in my space runs at 1140CFM. It is under $70, and compared to all the other fans I've seen, its a damn good price for how much air it moves.

http://www.grainger.com/Grainger/items/4C671

I am worried that it's going to be excessively loud, and that it may be too powerful. I am venting a room that is roughly 144 cubic feet (14ft x 10ft). I am running a Carlisle CC Bench Burner as my torch.

All this sound right to you?

[harpentuan]

If you tune in the exact amount of intake air (the formula escapes me) you could pull some air through that space with that fan. Provided that you dont have warehouse ceilings.

*on second thought two fans would be better than one. See I was thinking of my workspace which is only 8x10. I got a little messed up there. I didnt want to give you bad advice.

[Mike_Aurelius]

http://mikeaurelius.wordpress.com/ventilation-primer/

[canaan]

too many right angles in that duct system ..... poor example.

[J Howard]

i use 4 1600 cfm fans to ventilate a one car garage

[michaeL25]

Even if the ductwork/room was perfect, i don't think anything less than 2k cfm is appropriate. I say this because it's your heath that you are screwing with. Being healthy is worth the resources to get a very good venilation setup.

I have less than ideal ductwork/hood and work my space is about 1500sq ft with 12 ft ceilings. With a 1500cfm fan in the hood and a 3500cfm fan in the window, I know that my exposure to fumes is as minimal as possible. The test that I use is to open up my gas vales all the way on my torch, sit in my normal working position and try to smell the propane. I can't smell any propane with this setup. I also don't feel like crap the next day if I do a lot of fuming.

[n3rd]

good test michael. you can make that test visual by lighting a small amount of propane coming from your torch. a little propane from your torch will make a flame that gives off soot, a larger propane-only flame doesn't do it.

[barefoot stash]

One other point is to make sure have enough make-up air coming into your environment. This is just as important as the air you suck out. It's usually as easy as a couple of open windows and a door however, if you are in a basement or inside a structure, you may need to pump in air as well.