I am setting up my spare garage to paint my 72 SS and wonder what cfm of air flow I should have for good ventilation. My garage is 22'x 24' and I have a 30" x 40" window that I am going to put a low micron filter over for air inlet. I am trying to decide what size exhaust fan to install on opposite side of garage from air inlet. Any suggestions?

Get as big as you can afford, preferably a 2 speed.I used one with the louvers on the outside and put a monte carlo fanshroud over it on the inside,cut out a piece of plywood with insulation over it to put in the hole when not in use.That's if your in the cold part of the country!!! Mike

If the opposite side of your garage has the roll up door on it I stick box fans on the floor and exhaust from there. I don't know the CFM but I use 3 or 4 cheapy box fans on the floor with a piece of plywood cut for a spacer to fill the void if any. Close the door down on top of the fans and vise grip the door track to lock the door down on them.

Don't you need to use explosion proof fans?

I have always gotten away with the cheap box fans without blowing myself up, should have sealed fans I suppose. I use furnace filters on the fans, It also seems to work better for me if I use 2 or 3 exaust fans and
a good fan that moves alot of air on the othe side bringing air into the booth. It seems to keep the dust and crud down by having it somewhat "pressurized" instead of just pulling air out

<BLOCKQUOTE>quote:</font><HR>Originally posted by mrein:
Don't you need to use explosion proof fans?<HR></BLOCKQUOTE>. Good question! I was thinking of using some kind of filter for the exhaust along with the intake. Not sure if I am going overboard but painting is new to me. my compressor is in my attic and the garage is sealed off pretty good. I see some responses were others have tried furnace filters. I just came across a 450 cfm squirl cage fan today that they are throwing away at work. I think i will try it out with maybe 3 normal size furnace filters ahead of it. It has a 3 phase motor so I will have to buy new one. Do lights also have to be exposion proof? Calculating volume of garage and cfm of 450, it will take 8 minutes to exchange air (excluding loss from filters). Like I said, not sure if I'm going overboard but I've listened to many stories from my father in-law who is a retired fire fighter. Rather be safe than sorry.
Thanks for the info!

Yeah, the fans should be explosion proof. I haven't had a problem with it in 20 years but that doesn't make it right. It's those dang gas water heaters that will really set off an explosion. If your painting near one, shut it off. When your finished painting your need to keep the ventilation going and the water heater off till the paint sets up good.

<BLOCKQUOTE>quote:</font><HR>Originally posted by 67shovel:
[B]Yeah, the fans should be explosion proof. I haven't had a problem with it in 20 years but that doesn't make it right. It's those dang gas water heaters that will really set off an explosion. If your painting near one, shut it off. {/B]<HR></BLOCKQUOTE>

That scares the crap outta me....I would hate to have my house blow up. Can you put the fans outside the area and have the filter pulling the air or is it better to have the fan inside and push the air through the filter?
It seems it would be safer to have it outside the booth environment.

I've used the furnace filter setup. They work good and they're very cheap. Just set it up so you can swap them out between coats as they're only good for about one time around the car and then they're so restricted/clogged that you need to change them.
If you push air into the booth you reduce the chance of explosion as your passing nice clean air past the motor in the fan rather than solvent laden air if you were to put the fan on the exhaust side.
Lance

So you would also need an exhaust if you are pushing the air into the booth correct?

Is one clean air incoming and one exhaust outgoing enough filterering or would you need more for the incoming?

I used one 25" x 25" furnace filter on the exhaust side and it stopped 98% of the solid type stuff (the actually color) from getting on everything outside where the exhaust dumped out. I'm not real sure I answered your question with that as I'm not real sure what you were asking me. Feel free to email me direct if you'd like.

Lance

Thanks for the help everyone!! I checked the exhaust fan specs and its actually a 1000 cfm. I have it hooked up now with 2 furnace filters in two locations on the inlet side and exhaust behind the gagage. I am getting great ventilation with this set up. Thanks again to all for responses.

Wait a minute! your in Lake Shores Mich.? Hows the thermometer look?BRRRRRRRRRRR I'll bet.Better make sure that your metal temp. is above 60 F and your using a fast or cocktail med/fast reducer or my friend youlle be scoopin the paint up off the floor and trying to sift it back in the cup.I've sprayed at the 45-50 f range before,but you have to wait alittle longer between coats to let the paint breathe the solvent(reducer) out.Good Luck and let us see how it turns out