Exhaust Fan and Fire Risk - Advice Needed.

H

hoodun

I would like some opinions on my plan for my garage paint booth.

The ceilings are a bit low for me to put in a booth so I went with stapling plastic to the walls and covering the staples with duct tape (as well as stapling over duct tape). The walls are bare (no sheet rock). I did have to add some beams to get the width covered. Overall it is fairly sealed but I am not confident it is totally sealed.

Plan 1: I can use an outtake fan in a negative pressure booth with a filter (batting) for an intake. The fan I have is a Fantech 12 fKD, 2000cfm. They claim the motor is sealed but it is not flame proof. However, I have 50 ft of ducting and I will be placing the fan 50 feet from the house and in the booth will be a 60" x 20" activated charcoal filter with a filter element around it (the charcoal filter is rated for 2500cfm). I am going to wet the filter element slightly and keep the fan running all day, hours before and after I finish painting.

Plan 2: Positive pressure. Push filtered air(from the charcoal filter) through the room, possibly pushing fumes into the house and pushing fumes out into the back yard. The outtake will have batting or furnace filters.


I'm thinking plan 1. Being that the fan is 50 ft from the house makes it safer, in my current thoughts. However, we are talking about an exhaust going through 50ft of 10 inch ducting which is relatively condensed... ...its also being sucked out extremely fast and it will be mixed with fresh air being pulled in. The charcoal filter could also essentially catch all the fumes as can the damp filter around it, causing no fumes to hit the exhaust fan. Worst case I can see is a massive blow torch going off in the backyard. There is nothing back there other than grass.

I am not going to rent a booth at this point so please either advise positive or negative pressure.

Thanks!
 
As long as you keep an exhaust fan running there's very little chance of a fire.
It takes a lot of cloud to ignite, like heavy enough to not be able to see across the room.
It's not like gasoline.
There are thousands of painters out there every day with pretty dense clouds in their
garages from painting that light their cigarettes and keep going.
So as long as you keep it ventilated enough to paint properly, it's not a problem.
 
jcclark;41268 said:
As long as you keep an exhaust fan running there's very little chance of a fire.
It takes a lot of cloud to ignite, like heavy enough to not be able to see across the room.
It's not like gasoline.
There are thousands of painters out there every day with pretty dense clouds in their
garages from painting that light their cigarettes and keep going.
So as long as you keep it ventilated enough to paint properly, it's not a problem.
Click to expand...

Thanks. Thats what I was figuring.

I am probably going overkill by putting the fan out in the yard but I have the ducting so I might as well play it safe in preventing a vapor fire int he garage. Power could shut on and off real quick and with the fan coming on in the garage... so best to get it far away....I'm confident I will be fine in any situation. Worst case the neighbors will have a blow torch show.
 
Funny story I will share about plastic enclosures, We have to seal ourselves in at work when we are doing interior remodeling at larger companies to prevent dust. So we had to cut an opening in a block wall, when its a small enclosure we don't bother with the negative air machine a shop vac will clean the air very well. So in goes the guy but he put the shop vac outside the enclosure & just ran the intake hose in. Ok turn it on, guy outside flips it on instantly sucks the plastic in like a foodsaver machine & guy is trapped inside can't even move. After the guy on the outside managed to stop laughing he shut it off & had to cut the plastic to release the vacuum. Sure wish he took a picture first!
 
You must log in or register to reply here.
Back
Top