Air Conditioning and Dust in the Shop

A discussion of the dust control and air conditioner performance in wood shops. April 16, 2010

For the next summer I would like to install a air conditioned in my 500 square foot wood shop but I'm worried that the dust will shorten the life of the cooler unit. I'm wondering if anyone has any suggestions?

Forum Responses
(Dust Collection and Safety Equipment Forum)
From contributor D:
A prefilter, a prefilter for the prefilter, and an AirBear filter on the plenum. Keep the prefilters clean weekly and change the AirBear filter every season. Make a removable plate over A/C coil so you can inspect it for dust clogging periodically although we haven't had an issue with the prefilters and the AirBear filter. I hate hot so we keep our shop at 65 degrees all summer which is a real feat with all the heat produced by the compressor, CNC vacuum pump, and friction from the air moving through the dust collector at 9000CFM. Recovering your air from central dust collection becomes a necessity as well. We heat for very little but keeping 2700sq/ft cold in the summer cost about $180/month. Well worth it in my book. Plus we have great humidity control which is definitely a must for quality woodworks.

From contributor H:
If the dust in your shop is so bad that it will damage an air conditioner, it is probably already damaging your lungs. I have two air conditioners in my shop. They do get some dust, more than in a house, but not much. I also have two dust collection systems, both of which vent to the outside with no air return, and I vacuum the shop a lot. Heat and cool air loss is minimized by being careful about when I do which kind of work, and I work alone. I try to mill in the morning in the summer, and at the end of the day in the winter.

From contributor M:
My 8000SF 12-man shop was air conditioned for the last six years I ran it. I built steel stud and sheetrock walls around the HVAC equipment in two locations and let the air flow through standard spray booth filter grids. Each was a four filter square arranged vertically. The dust collection was a cyclone style with a rotary dust foot that emptied into a dumpster and the return air bags were located in another small room with spray booth filter grids in the walls too. It all worked very well, did not restrict flow or efficiency, kept the dust to an absolute minimum and was really inexpensive to set up. The HVAC equipment itself even stayed very clean. The compressors were located outside in a shed, and the whole operation was about as quiet as I have ever heard a shop.
The AC was a serious boost to productivity. You may not get it down to 65 in the summer, but it sure took the edge off a 90-degree day, especially when the spray booth was not on eight hours at a time. Exhaust air from the booth was the biggest heat loss issue.