Were that permits included as well? I'm not sure we can vent to the outside. Ill check on Monday. And negative pressure? Please elaborate. Also we cant really put walls up. Is there a way to maybe put a roof type awning or clear material like they use to keep cold air in. In large walk-in coolers? Cleaning the shop, ive found alot of dust. So i know thats going to a battle. We have a vent on the roof in the middle of the warehouse. With a fan.so your saying make a hood restaurant style and vent to the outside?. So no carbon filter needed? Or use both?
Frame out a room with a ceiling. I don't know about permits as he built it inside his attached 2 car garage. (probably no permits).
Negative pressure is like when you enter a lab. The air inside the room is being drawn out by a fan causing the pressure inside the room to be lower than the outside. When a door gets open the air rushes into the room rather than out of the room.
I personally would use a large commercial exhaust hood & fan. It would suck all the air from the room and pull it out with a filtration system in between that way what is exhausting out is sterile.
You don't want the room air tight but I would seal the walls/ceiling in visqueen just to cut down on dust particles. I would also run a few filtered vents into the room using dryer vent pipe with standard fiberglass air filters to ensure a proper flow of air into the room while also cutting down on dust. A raised floor with cheap vinyl flooring wouldn't hurt either.
I would frame the walls outside in. Using sheets of plywood covered in visqueen for my walls inside. Leaving my exposed frame on the outside. Fairly basic carpentry.
Also, depending on the amount of exhaust pipe length wise you're running you're going to need to calculate the fan size to be able to pull enough air out to exhaust it so you don't bottle neck and cause it to backdraft. Straighter is always better.
