I have an open face 10' wide spray booth located in one corner of a 104 x 54 shop. I currently draw outside air from a couple of windows that are 50' from the booth. The problem I encounter is keeping enough heat in the building. I am a small custom shop and don't want to invest in a makeup furnace, and don't want to pay to operate one either.
I am thinking about rigging up a duct to pull the makeup air from the attic. This would temper the air a bit before it enters the shop. I am located in a climate that gets cold in the dead of winter (10-20 deg), but there are many days late fall and early winter that the outdoor temps are around 40 deg. The building is a metal pole building with a steel roof. It is very well insulated.
Has anyone tried such an arrangement? Dust in the finish area is really not an issue as I work alone or with one helper. I was thinking of placing the air inlet from the attic at the far end of the shop to reduce any turbulence to a minimum. The ceilings are 15', so I could bring the duct or chase down low enough that it could be reached from the floor to open and close. Does anyone have any thoughts?
From contributor M:
We put an adjustable digital switch on our fan so after spraying we could turn it down to a low speed. I live in Maine and its worked well. It still gets a little cold when we have a lot to spray but not as bad as before.
If you use an AAA and high solids finish you will find you need to move very little air to keep the environment safe from exposure and explosion. I throttle my air input (windows) to account for outside temp and my comfort. Bottom line for me was to invest in better spray equipment and use higher solid finishes to minimize the clouds in the shop. When you get these under control you can get by with a much smaller fan. I also rigged up a radio control remote power switch to be able to turn the fans off when I'm not spraying (one man shop).