Re-Circulating Filtered Air in a Paint Booth

There is technology to filter and re-circulate exhaust air from a spray finishing operation, but it is prohibitively expensive. June 8, 2008

We are expanding our finishing department and looking into a self-contained spray booth that has some type of filter system to remove the VOC from lacquer and other solvent base finishes. I was told there is such a unit, but I'm unable to get info on it. I would like to put the unit in a large open building, pull heated air from the building, use through the booth and recirculate back into the building. Is there a system that does this by removing the VOC in the exhaust unit of the booth?

Forum Responses
(Finishing Forum)
From contributor C:
The booth exists - it's an automotive downdraft booth, but I don't remember the name. It worked by pulling the air through activated charcoal filters as the final step of filtration. Saab cars installed many of them back in the 90's. They were expensive to run because of the charcoal needing to be replaced daily. I think they ended up pulling them out and doing something else. They also had smaller units where you could roll them up to do partial paint on damaged car areas. You might try contacting Saab to see if they can help.

From contributor J:
I think you'll have a hard time finding it because NFPA 33 prohibits exhaust air from spraying operations to be recirculated except to an unmanned spray operation. NFPA 33; 7.5

From contributor C:
See - they make what you're looking for I think. If not, then search using "activated charcoal automotive spray booths." There are others including custom manufacturers.

From contributor A:
I checked into the mobilespraybooth units a year ago. They are very cool and very expensive - small mobile units beginning at about $12K if I recall correctly. Also the small mobile units are not meant for large scale finishing operations. They have multiple types of filters incorporated into the unit with the carbon one capturing the VOC's. Replacement filters are expensive and can only absorb for about 8 hours or less before they have to be replaced.

From contributor C:
Try - makers of the portable one.

I agree, expensive - but as far as I know the only technology out there that will do what the questioner seems to want. The larger booths that Saab had were much more expensive, and the filters were changed more than once a day automatically. That's why I don't believe they still have them, but I could be wrong. Booth manufacturers will make anything you want, but it'll cost you an arm or a leg.

From contributor J:
I checked and those are limited finishing work stations. That means no more than one gallon of finish in 8 hours.

From contributor C: - makes industrial size booths with carbon purifiers. Very expensive, but you're not going this technology cheaply.

From contributor S:
Contributor J is 100% correct - why can't you vent out and install an air make-up system?

From the original questioner:
Thanks for everyone's input. I was told there is such a booth, and there is! Only one thing, it's way out of our budget. The idea is great to recirculate the heated air, but most likely we would not be able to recoup the investment. I do like the mobile unit that some suggested and sent for cost and info on it.