CFM Recommendations for Spray Tanning Room

[LibertyTree]

Hi guys, I went on a call for a salon that is complaining that the spray tan room does not ventilate well enough. They have 2 6" exhaust fans that do not work worth a crap. The room is about 6'x17' and they use some sort of air compressor contraption that sprays this nasty orange spray tan stuff. What do you think would be the right fan to remove this stuff from the air. I would also need make up air as well, the room is pretty tight. Also, the existing fans are 120v run off of a 20a circuit, I would like to be able to re-use the circuits, 1 for the exhaust and 1 for the make up air. Depending on the CFM for the fan I may not need a makeup air fan, an electric dampered combustion air doohickey might work. Opinions?

[Pete838]

How many CFM of supply/return/exhaust air do you currently have? You want the room to be net negative on airflow so the odors don't escape the room. Makeup air would be at least partially supplied by your supply if there is enough of it and as you say the room is tight. if you don't have plenty of supply it will end up as a makeup air temp room.

If you are treating it as a spray booth (like for painting cars) the requirements can be found in NFPA 33. You would need 100 linear feet per minute of exh. air flow and "Makeup air shall be provided at a rate approximately equal to the rate that air is exhausted by the hazardous exhaust system" according to IMC 510.5.5

Not suggesting you need a spray tan room with an industrial spray booth setup, but the solution lies between there and your existing fart fan.


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[LibertyTree]

Thanks for the reply. It wont need paint booth exhaust for sure. I was thinking around 400CFM but I'm just not sure.

[Pete838]

I would be looking at Loren Cook AC type fans. They are centrifuge type fans and can go through the wall or roof. If you get one a bit larger than the 400cfm and set it up with a potentiometer you can dial it up or back based on their needs.

[genesis]

I did one many moons ago and dropped a return in the space with a merv 13 filter I think I was running about 500cfm. For whats its worth its been operating like that for over 12 years with no issues.

[LibertyTree]

I would be looking at Loren Cook AC type fans. They are centrifuge type fans and can go through the wall or roof. If you get one a bit larger than the 400cfm and set it up with a potentiometer you can dial it up or back based on their needs.

Thanks, any ideas for make up air?

[Pete838]

Thanks, any ideas for make up air?

Can you dump conditioned air into it on the opposite end of the long space? A straight OA makeup fan is going to make that room really uncomfortable 10 months out of the year. The air would be outside temp unless you were to condition it, and that's big $ for such a small project..unless your client has deep pockets and wants to do it "right". Chances are if the building is big enough and not extremely tight you're getting enough OA infiltration anyway.


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[LibertyTree]

Can you dump conditioned air into it on the opposite end of the long space? A straight OA makeup fan is going to make that room really uncomfortable 10 months out of the year. The air would be outside temp unless you were to condition it, and that's big $ for such a small project..unless your client has deep pockets and wants to do it "right". Chances are if the building is big enough and not extremely tight you're getting enough OA infiltration anyway.


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Thanks for the reply. The building is a pile of crap. The owner is willing to spend a reasonable amount but I'm certain there wont be an HRV or anything of the sort going in... I think there is a floor register in the room but I'm sure its putting out 150CFM at best so it wont match the new fan at all. It is pretty tight too. Plus what happens if the furnace doesn't happen to be running when the fan turns on. There is certainly a dilemma here. I wonder if I could run a wire to the G terminal on the furnace from an electronic make up air damper that would force the furnace fan on when the damper opens? 150cfm might be better than nothing.

[Pete838]

The simpler solution might be to just switch the thermostat to FAN-ON during occupied hours... Assuming you can dump enough supply air in there.
interlocking the blower fan with the exh. fan (or the opposite) would ensure nobody tampered with the T-stat.