a question about exhaust fan position for a spray booth

Hi,

I had been running a cardboard box with some 3" cardboard tubing running about a metre to a bathroom exhaust fan until recently. The main problem with it was the because the fan is like 10" and the tubing was only 3" there wasn't enough of an opening to run the fan at full speed. I hope u get what i mean!

The fan is rated at over 200CFM. I have got myself some A/C Ducting now. 100mm stuff.

I will soon purchased some wood to build a proper spray booth but am unsure of where to mount the exhaust fan. I have seen some desgins with the fan out the window, and others with the fan right at the spray booth blowing down the ducting.

I think having the fan at the spray booth would be the best solution for me but i do have some concerns. Firstly, if I am sucking 10" of air at 200CFM and blowing that down a tube that is only 4" wide, is that going to cause some sort of air pressure problem? Will the fan still spin at the 200CFM mark?

Also the fan at 200CFM will it be too fast for the spraybooth whilst painting? like i am hoping the fan doesn't suck the paint right off my model i am painting! lol

A quick question on the actual size of the spray booth. Umm what size?? From what I have been reading up on, by my reckoning 15" high, 20" wide would be ok for me. but how deep should the booth be? i am thinking atleast 10".

Also one last question. I see alot of designs that have plexiglass as the door for the booth. Is there a specific reason for that? other than to keep dust out i don't really see why it would have to be clear.

Thanks for any tips, hints and advice you can give me. :evillol:

Werdy666

There is a tutorial on this at www.briansmodelcars.com that explains fan placement and everything.