hazardous location

[Gaffen99]

I have a paint mixing room in an auto body shop with an exhaust fan to vent the fumes. The owner want to shut the fan down at night and I advised him not to due to the vapor build up that could occur. Is there an article stating whether this fan should be continuous, to me common sense would say that it should.

 

[bdarnell]

Read through Article 516, specifically 516.3. It does not direct how an area is to be ventilated, but gives some guidance as to how an area is classified based on the ventilation equipment operation. The wiring methods used will have to be specified based on these classifications.

I agree that your concern is valid, but the NEC doesn't require it as I read it.

 

[dlhoule]

Once the operation is shut down for the day, I see no reason to run exhaust fan for more than 5 or 6 air exchanges. IMO this wouldn't be much different than purging a gas fired furnace. :idea:

 

[benaround]

Gaffen99,

You could show him where the breaker is and let him turn it off and on there, that way you didn't change any existing wiring to the fan.

FYI. just completed a custom car shop with paint booth etc. and 'air' systems were 24/7.

imo it's a good idea to keep it running/cycling.