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I'm building out a small public makerspace and would like to add a ventilated painting and staining booth. I'm expecting the size to be about 12 cubic feet (4' x 3' x 1'). There will not be spray guns, only stains and regular spray paint. The average surface area painted will be less than a sheet of paper, often less than a golf ball.

The opening will be about 3' x 1'.

I've read that one is supposed to have:

"100 CFM per linear foot of hood width for spray painting operations"

This is re-iterated in this question: How many CFM for a range hood do I REALLY need?

This seems excessive for the usage I'm planning. Every other resource I found on calculating CFM was focused on much larger projects with the intention of spraying (or cooking) constantly.

How can I figure out the CFM needed for something like this? Around what range should I expect?

EDIT: Most pop-up spray booths on Amazon are showing ~110 CFM in their specs https://www.amazon.com/s?k=spray%2Bbooth

Library Seph
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    5 or 10 exchanges per minute should suffice, which is about 60 - 120 cfm. A bathroom fan should work. That figure is high, but in a smaller area you need faster exchange since the vapors will build up faster than inside a larger chamber. – dandavis Apr 12 '23 at 18:41
  • Oh, that's great. We already have a 370 CFM fan drawing from the laser cutter (on top of the fan it already has). I suspect there's a way do both. I also found that various "pop up spray tents" on Amazon had ~110 CFM. – Library Seph Apr 12 '23 at 18:46
  • well, with paint, you probably want a cheap air filter between the intake and blades/impeller. A cardboard box with in/out holes cut on diagonal opposites can hold a small (cheap) 16x20 filter than will keep a lot of the vapors from coating the mechanics and slowly reducing efficiency. – dandavis Apr 12 '23 at 19:06
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    Oh and do check the motor as paint spray may be flammable or perhaps a better word might be explosive... – Solar Mike Apr 12 '23 at 19:34
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    You absolutely need an "explosion-proof" fan (motor) for this job. – Ecnerwal Apr 13 '23 at 15:21

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Too much air flow is not good for spray paint

Recommend to get fan speed controller

Since it is not possible to predict the correct airflow for spray painting. You definitely do not want windy conditions

Traveler
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