Q&A: spray booth

I have a paint room… roughly 9-6"w x 22’ long. The entrance has a 4’ wide door and the rest of the wall is where the fans are located. I just picked up a 36" fan (an aluminum one meant for spray booths) and have to install it. I have an existing opening (36" hole) located at the the bottom of the wall (resting on the floor as I had a scroll cage fan above the old fan). I’m thinking I should raise the fan to the centre of the space and get rid of the scroll fan ( I can use that fan in my welding shop). I can’t put it on the roof as I’m renting the space. So questions are should I raise the fan to the centre of the wall and how much space should I allow between the fan and the filter wall? (space is tight) Also, should I have panels in front of the fan directing airflow to the fan? I know it will probably be a bit better but will it be a drastic change worth the effort (a panel would have to be hinged and would block the exit while open) or just slightly better? My existing system is ok but my 36" drum fan keeps cutting out which I suspect is from the lacquer build up in the switch. I’ve wanted to swap it out for a safer, more reliable fan and finally found a used one. It weighs a lot and needs a 3 hp motor to power it so raising it will require me fabricating a stand, shroud etc). Happy to do it if necessary but only if it would be a significant improvement