Really like the PVC pipe paint booth. Great idea! What/how are you covering it?

You might want to go for a large filtered opening for AIR into booth and a smaller AIR outlet filtered.
That way you get a suction effect and not breezy coming in.

I spray the floor with water to keep it wet. Keeps dust from kicking up and the paint dust drops on the water and does not stick to floor.

I wonder if you could stiffen the PVC pipe by filling it with spray foam or some other material..