Replies

1. 
   user-2450400 | Jun 20, 2020 08:50am | #1

   To install a serious exhaust fan in a shop,there are concerns for the drop down sides,as attractive as the concept is,the plastic will be drawn in to the spray booth area and in my view create a problem there. Also,in a cold environment the shop must be heated and the furnace must be considered. When the fan is in use,the air must enter the shop. Take care not to suck air down the chimney! I use an old furnace fan for my shop controlled from a switch that chooses either gas furnace or exhaust fan. The shop is a multi function shop that involves wood work as well as automotive "stuff". I located the fan outside in an enclosure that also houses the air compressor. A back draft damper was fashioned from very thin aluminum and placed on the outlet of the fan.I have a manual damper valve in the ductwork leading to the fan but have never found it to be necessary. My spray booth is solid walls and the same size as the one you propose.

2. 
   carbide_tipped | Jun 24, 2020 09:12pm | #2

   What will you be spraying? If only water born finishes, you can use almost any fan that moves enough air. If you will be spraying anything flammable, like shellac or oil born finishes, or real lacquer, then you need an explosion proof fan and they get expensive quickly. As previous reply stated, you absolutely need a source of makeup air to avoid back drafting of combustion appliances.

3. 
   woodshedding | Jun 24, 2020 09:37pm | #3

   I use mostly water-based finishes but shellac is used on occasion so I expected to need an explosion proof fan. If you have specific suggestions as to models to look at or avoid that would be greatly appreciated.
   Re Makeup air. What I’ve done until now is just keep the shop door open (it is the back entry to our house). I’m not clear why that isn’t enough?
   The plastic is weighted by attaching it to a board that rolls up with the plastic when not in use. It has worked well to minimize the plastic getting sucked into the spray area.

4. 
   AlbertL | Jul 08, 2020 08:50pm | #4

   I have a dedicated spray booth setup thats about 2.4m x 4m (8 x 12. )

   I purchased a second hand explosion proof fan. you want a fan you can adjust the blade pitch. most proper spray booth fan will let you adjust the pitch of the blade, the pitch will determine how much air is moved in the shed. basically you want 0.5m per second of air movement. the larger the room, the higher the pitch to move more air.

5. 
   woodshedding | Jul 08, 2020 09:49pm | #5

   Thanks for the response. What make fan do you have? What is its size?
   Thanks

6. 
   AlbertL | Jul 09, 2020 07:42am | #6

   I have a Hison fan. the external housing is about 34 inches, the actual fan is 30 inches tip to tip. it came out of a professional spray booth.

7. 
   mikaol | Jul 09, 2020 10:17am | #7

   Hey,
   User 245... is a trifle paranoid, but he makes a good point. Still, it'd have to be a huge fan to suck the plastic in, especially if it's weighted. If that's a concern for you I suggest you tape the shroud closest to the fan to the sides of said fan.
   The fan itself could be a regular floor fan. I use one myself & don't worry as long as the wiring's solid. Meaning no wires are frayed causing an arc.
   Last...experiment. You'll figure it out if you don't over-think.
   Good luck,
   Mikaol
   To keep air off the fan when it's idle, try an air conditioner cover. You can pick one up most anywhere. A regular tarp might work, too.

8. 
   oxmach | Jul 09, 2020 02:33pm | #8

   I picked up a barn window exhaust fan from Princess Auto here in Ontario, but a farms supply or maybe Harbour Freight may carry them.
   I build a box that had 4 furnace filters (2 wide x 2 tall) and picked up same size paint booth filters which have a sticky coating on the face to put in front of the furnace filters. So basically 8 in total. The fan was on the back and pulled air through the filters. It was strong enough to hold a sheet of paper. Only used water base but it worked very well indoors. A booth made up of painters drop cloth contained any overspray until it could get pulled into the filters.