On 6/19/2017 9:23 PM, DerbyDad03 wrote:
I've often heard that using a bathroom exhaust fan to exhaust finishing odors
is bad idea, but I'm sure there are certain conditions that would have to be
present for it to really be a danger.

Consider this room:

9' x 12' x 7'
South West corner: A door that opens to the main part of the basement
North West corner: A door that opens to the great outdoors (screened)

Consider this idea:

Mount a 140 CFM bathroom exhaust fan in the North East corner (opposite
the 2 doors). If my calculations are right, that's about 40% more than
the minimum CFM for a bathroom of that size.

https://www.amazon.com/gp/product/B01E0KV5J0

Planned uses: Occasionally exhaust odors from primer, paint, mineral spirits,
oil based stains, oil based poly, farting, etc. No spraying. Brush or wipe-on
only. Small projects or small parts of large projects. e.g. stain a headboard,
paint a dresser, etc. Not to be used when the air is dusty, although
adding a holder for a furnace filter is a possibility.

What would it take for this to go boom?

FWIW, the fan shown below, placed on a stool by the door to the great
outdoors hasn't blown the place up yet. Of course, it's only been about 35
years, so there's still time.

http://i.imgur.com/QzieJU1.jpg

That thing is a beast. I don't know the CFM rating, but it'll dry a pair
of jeans in about an hour.




I am no expert on this but IMHO any "not rated for explosive fumes" fan
can cause an explosion if the air to fuel mixture is right.
One step to insuring that the air fuel mixture is not right is to have
the fan on BEFORE you mix the fuel into the air. Read that as keeping
the fumes dispersed before they have time to accumulate. IF the fuel
concentration is to low to begin with there is less chance of the fan or
it's switch creating the spark in the explosive environment.

Personally I would not draw fresh air in to exhaust out through a small
fan. If the fan does not exhaust directly out side, or if the duct has
a leak in the attic, you might be causing a dangerous situation in your
attic, or where ever the duct work runs.

I would pressurize the room to vent fumes out the large doors. Run the
exhaust fan backwards. Or put a fan on the south door blowing in and a
fan on the north door blowing out. AND another fan in the room to keep
the air moving.