# Dust Collection Unit Located Outside the Shop



## jimmymac (Oct 16, 2009)

I am designing my shop and plan to put a cyclone dust collector outside the wall of my shop. However, I am wondering about returning the air back to shop the dust collector pulls out. Since I will be heating or cooling the shop most of the year will I have to live with the lose of this air and just draw in new when the dust collector is running or is there a way to pull the air back into the shop from the dust collector.


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## bobkberg (Dec 26, 2009)

The first question to cross my mind is: Is the blower output readily accessible for return ducting? 
Second question would be: Will the added load on the blower impact its effectiveness?

If the answer remains workable, then I'd just duct it back to the shop, but run it through two filters: coarse and fine. The coarse one to not clog up the fine one. If the added ducting and filters put too much of a load on the dust collection blower, you might need to add another stage before the filters.

My hesitation here is because I don't know how much dust stays in the air stream after it's been through the cyclone collector, so filtering is a must, both for breathing and fire/explosion danger.

An alternate approach would be to use an air-to-air heat exchanger (the two air flows pass by each other, separated by thin sheet metal. This is not ideal from several points of view (added number of fans, possible dust buildup on the heat exchanger building up an insulating layer which defeats the purpose, noise, occupies more space, and the electric bill), but it would enable you to cut the temperature differential on your incoming air. Depending on the other factors (electricity to run the blowers), it would allow you to bring in cleaner air than just the output of the cyclone collector. However, these devices are usually used for air exchange in homes where the objective is to exhaust CO2 and odors and such, but recover some of the cost of heating or cooling the incoming air.

I hope that helps,


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