Insulated intake vent, on turn buckles to seal it tight, the vents are thin sheet metal with foam cut and put in them, when all the vents are closed the shop is pretty airtight, I took out a couple of windows, that way if somebody wanted to break in, however not a problem where I'm at they would have to go through the service door that faces my house which is about 12 feet away. Looking at these pictures everything looks kind of dirty and grungy looking, I need to put some fresh white paint, but all these vents have been used for many years and I have never had to work on any of them, it's a simple setup, but I didn't have to run a maze of ductwork to get this type of ventilation system. I apologize for the dirt, but it's still used for mechanical as well as bodywork.
Open for business
Outside intake vent, never know that some old guy is inside trying to reinvent the wheel.
Exhaust fan vent
It was late at night when I took this, the flash worked, thats a sixteen foot steel insulated door, menards special, always wanted a 34, it might only be a picture but i've got one.