Hey guys. I don't paint cars but rather knives So don't hate on me! I wanted to come here to the experts as I am sure some of you have dealt with this or may have some ideas.

So I build a small paint room (approx. 11x8') that I have installed an intake fan and an exhaust fan on which I have individual control over so I can get slightly positive pressure when painting.

My problem is that, while I live in SC and it's warmer here, the winter is coming and I need to figure out heat. My shop is a 12x40 building and I build this paint room totally enclosed and sealed off, at one end. I have a down draft air flow system, which sucks air in from the open loft above it and blows it out through the floor. My shop is actually heated w/ a mini-split air system, but the paint room is not.

What happens is that the intake fan has to suck air from somewhere and it's sucking it in from the open loft, which is the same air that's heated from my shop. Well my shop has to get air from somewhere to put it into the paint room, and it's getting the fresh air from outside from the two attic/loft vents. This is causing an issue so that my whole shop cools down and gets cold because of the air flow through the whole building.

What I want to do is run duct work from one of the loft vents (that goes to the exterior) so the intake fan can pull it from outside, blow it into the paint room, then blow the exhaust fumes back outside through the floor. All this being said, I need some type of in-line heat coil or something that I can put in the duct work prior to it getting to my paint room so the air blowing in is semi warm.

Any ideas? Will try to get pics so you can see what I'm talking about... The good news is that I have a friend who is an HVAC tech and can help a bunch.

Welcome. You should post up some pictures of your knives we'd love to see them.

Your HVAC friend will be able to point you to inline heater elements; they use them all the time for heat pump systems as auxiliary/emergency heat when the outside temp is too low for the heat pump to work.

Be prepared to pull out your wallet though, it takes a lot of energy to keep that incoming air warm.

An alternative would be an (explosion proof) heater inside the booth.

chris wrote:Welcome. You should post up some pictures of your knives we'd love to see them.

Your HVAC friend will be able to point you to inline heater elements; they use them all the time for heat pump systems as auxiliary/emergency heat when the outside temp is too low for the heat pump to work.
Be prepared to pull out your wallet though, it takes a lot of energy to keep that incoming air warm.

An alternative would be an (explosion proof) heater inside the booth.

Thanks for the advise! Yes, one thing I ended up considering is simply putting a torpedo/tubular propane heater up on the one loft side (making sure there is no fire hazard of course) so it warms the air as it is sucked in my shop but before entering the paint room...

thanks for the help!

Here are a couple =)

very nice, I like those. The photos are excellent, too. Good luck with your booth project.