A photo and a tutorial would be an excellent idea. I am thinking of something for my basement so I can prime my stuff with out being able to smell it on the 1st floor.
Are you using solvent based primers?
Very few airbrush booths are rated for that. Most have direct drive motors similar to computer fans or small desk fans. Solvent based paints require explosion proof motors or belt driven fans where the motors are not in the air stream.
Secondly, to avoid the smell upstairs, you'd need charcoal filters. Again adding substantially to the costs. Organic solvent vapors are not good for you in long term exposure.
Do your priming outside on the patio.
*****
I have shot oil based paints (in larger guns than an airbrush) in a bedroom. I redid my kids' bedroom sets. White primer, colored paint and a clear coat. I put a large box fan in the window and left it exhausting air to the outside. Pulling enough air under the door so that I wasn't pulling a 'vacuum' in the bedroom. I was wearing my bunny suit, face shield and respirator. Left the door closed and the fan on for a couple hours after I finished shooting. Then just left the door closed and the window open for the rest of the night.
As I would finish, the room would have a nice fine haze in it. (we were about to repaint and re floor in that room anyway). I was glad for the respirator (not a dust mask, but a respirator with NEW organic vapor cartridges. (They look fine, but go bad in about 6 months after you open them.)
When I finished, I noticed that the screen on the window and the fan blades had some interesting colors.
Smartest thing I ever did? Probably not... If I had put enough lacquer thinner in the air to set off that fan motor, life could have gotten very interesting.