Spray Room/Booth Ventilation

[bud]

A buddy of mine just built a small building to do finishing, etc. on instruments. Should we be concerned about the type of fan we should use to pull the fumes out of the shop? We were thinking about the possibility of fire and if a special type of fan that would not cause any sparks might be necessary. Are we being too anal? http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

Thanks,

Bud

[Chris Baird]

Not at all. An explosion proof fan is a very good idea. Same with adjacent light fixtures etc.. It is hard to predict what areas are conducive to creating a potential flash point concentration. It is best to just assume yours will.

[Ken]

If you are spraying and venting any kind of a flammable finish you need an explosion proof fan. Period. A regular fan is an explosion waiting to happen.
Ken.

[Dave Cohen]

Not only that, but if you build w/ a permit, you will be [/U]required[U] to install an explosion-proof fan, hooked up w/ metal conduit w/ compound in it. Also explosion-proof light fixtures if you are going to use them. The light fixtures cost a ton of money for not very many watts, so you will probably be forced to just make the rest of your shop outside the spray area well-lit.

[Donald]

Don't forget the switches, they must be explosion proof, they are a source of sparks. One solution to the explosion proof lighting I saw in a spray booth was to put sealed plexiglass windown in the ceiling and then use ordinary fixtures over them, since they are outside the sealed booth. You can also put as much equipment outside the booth as possiable,(switches, etc.). But conduit entering the booth will have to be sealed with special fittings and poured sealant, to keep fumes from coming through the conduit out of the booth. By the way conduit in the hazard area will have to be threaded "ridgid" conduit.

[Dave Cohen]

The local building inspectors wouldn't let me use the sealed plexiglas light fixture option, so I chose to do without any lighting in the booth area.