Paint booth airflow requirements

[Senile Old Fart]

I have wondered how much airflow is the norm for a commercially built paint booth.

Watching video of painting in a commercial booth there is little over spray in the air, something I can only dream of,lol..

I came across the OSHA minimum requirement for airflow in a paint booths.

OSHA 1910.107 requires 100 lineal feet per minute for non electrostatic paint.

To calculate this flow rate take the width measurement in feet and times it by the height measurement in feet. The length of the booth does not matter, just the cross section.

example: 14''w x 9.5h = 130.5 x 100 = 13,500 cfm.

No wonder I am in a fog, my setup moves 2500 cfm @.5"wc. and my "booth" would require 16,000!

 

['68 Coronet R/T]

100' per minute air flow is for Crossdraft booths while Downdraft styles use 50' per minute.
Either way this formula produces CFM requirements far and above what most homemade booths have.
Another consideration is the amount of filter surface on both the intake and exhaust side. If my booth measures 14' wide by 10' high but my filter surface area is only 4' x 4' the result is turbulence in the booth. Or say my intake filters are 10' x 10' but my exhaust filters are 8' x 10' then I will have a positive pressure booth due to the restriction on the exhaust side. None of this is taking into consideration static resistance produced by duct work.

 

[streamlinecollision]

A commercial build spray booth typically has a minimum of a 24" exhaust fan. Typical of a cross draft style booth for cars & pich up trucks etc. Moving up in size for larger booths or some have more than one fan that can be adjusted to raise or lower the air pressure in the cabin. In any case the key to proper air flow is volume of air. So having the right size exhaust stack & intake are key. A fan in the wall is going to move less are than a wall of filtres with a proper sized exhaust stack can.

Rob