> I assume you mean restrict the air flow only to test the actual workings
> to see if with reduced flow that vapor odors show up. Then remove the
> restriction and see if the odors dissipate. Right?
You want to build a fume hood similar to a chemistry lab, closed on 5 sides
with an open front. Try it out and if you smell fumes escaping you need to
increase the air velocity into the hood by restricting the size of the front
hood opening. Some fume hoods have pull down fronts that allow you to vary
the size of the opening. Open to put stuff in, and partially closed when you
paint.
Fume hoods also draw vapors from the back as close to the bottom as
possible. This ensures that heavy gases like solvents are sucked in. You
might provide a duct across the entire back of the enclosure to make sure
the air flow is uniform, otherwise you might have a problem when painting
toward one of the corners. This should also ensure you are not trying to
paint in a wind storm that the fan might produce. Personally I would double
sheet the back of the hood. The outside plywood would have a hole in the
middle for the fan, the inside thin plywood would be separated by a few
inches and would stand a couple of inches away from all sides of the hood
(biggest gap at the bottom). I would also put in some 4 inch holes at places
where you think the flow might be a problem, like the back corners. You can
adjust the flow by fully or partially blank the top/bottom/side slots and
the 4 inch holes with sheet metal as needed. If your using a spray gun
remember that these generate a LOT of vapor especially if you are shooting
at 50 psi so use a big fan and provide lots of openings.
Don't for get to put in TONS of light, you'll need it.
Again once you build it and find that it still allows fumes to escape then
restrict the size of the front opening.
> Thats why I querried all you experts!
Talk about the blind leading the blind!
Hope this helps
Lee
|