.....After looking at what David posted, you might have some luck with this......
Instead of pulling in fresh air with a bathroom exhaust fan, have a shop vac suck the air thru the filter. Use charcoal filter material in the canister ....like you would use in an aquatic aquarium...fish, turtles, etc.....or place a charcoal filter over the exhaust port ...where the check valve/ball is located for wet vacuuming to prevent over filling....or use both. I'm thinking that the charcoal material should absorb enough fumes so long as your not painting for long extended periods at once....as an example , spray your first coat, allow it to dry, shoot your second coat, allow it to dry, etc. etc.