Class 1 Div 1 Ventilation

[PaPa D 13]

I am installing a ventilation fan through the exterior wall of a class 1 division 1 room used to compress methane gas for supplying fuel for our generators. The ventilation fan would be mounted on the exterior wall of the room and operated by a switch located outside the building. I am sure this area would now be a classified area but I can not find it in the code. I have three questions.
1) Would this area around the fan now be a classified area? Please direct me to the proper code or codes.
2) I can install a supply fan drawing fresh air in to the room or I can install an exhaust fan pulling the air from the room. Will both options fall under the same code or will the supply fan fall under a different code or exception since It will be pressurizing the room? Since the fan will not be running continuously I believe it will not make a difference.
3) What if the motor was located outside of the airflow of the fan?
Thank you in advance for your he. Please provide all code references.

 

[petersonra]

I think once you cut a hole in the wall for the fan, at the very least there is a 6 foot volume around the hole that has to be division 2. That would seem to apply whether there is a fan in the hole or not.

I think you will have to get better advice from someone who does this for a living though.

I have seen this handled by putting the supply fan someplace (like up on the roof) that is not classified and running duct work to the classified area.