Hello this is my first post, I'm building a spray booth in my workshop so I thought I would share my work in progress with you all. The booth isn't the biggest but due to the space I have this is what I have made. It's 2meters by 2meters by 2metres high.
I've have used pvc plastic on the top halfs of the sides to let as much light into the booth as possible. I want to use it as a negative pressure booth and I am going to make a box of filters in the corner with a centrifugal fan mounted on top for extraction. As for an inlet I'm still not 100% sure how big to have it and where? Any suggestions?

Welcome to the forum. Best bet is to make your intake the same or slightly larger size (in overall square inches) as your exhaust. I say "slightly larger" because if you put a filter on the intake it will reduce airflow a bit.

Too long to go into here but there is a balance in a paint booth of CFM versus velocity. Here are an older thread with similar discussion:

viewtopic.php?f=5&t=20596

Hi Chris thanks for your info. I'm going to be making the filter bank in the corner of the booth at a size of 1500mm x 50mm . Do you think this would be big enough as an exhaust filter for my room.