Evaporative coolers in the workshop

[Gary Salisbury]

This isn't a woodworking question but one regarding the workshop.

Is anyone using an evaporative cooler in their workshop? Does the higher humidity level rust your tools? Any other issues?

I'm getting ready to build my workshop and need to plan for some kind of air conditioning and an evaporative cooler caught my eye. It looks to be a pretty economical method to cooling a hot shop.


Gary in Sunny San Diego

[Lee Schierer]

I would say that an evaporative cooler would not be a good idea in a wood shop. Not only could rust become an issue on the tools, but the wood will absorb the higher moisture as well and give you problems when projects are moved to dryer environments. I think there was a discussion of this topic a few years ago and it is likely in the archives.

[Ken Fitzgerald]

I agree with Lee! Tools and the wood would react negatively to the increased humidity.

[Bruce Page]

I have run a swamp cooler in my shop for many years. I don’t experience rust or swelling problems. Maybe our single/double digit humidity is a factor (6% as we speak). I keep a good coat of Johnson’s paste wax on the cast iron and keep the water flow on the cooler pads trimmed down to a minimum. I installed a flapper vent in my shop ceiling that exhausts the air flow through the attic, that in turn helps keep the attic temps down.

That said, refrigerated air would be a much better choice.

[Jim Andrew]

My wife's family used a swamp cooler in western Kansas, she thought they were a great thing. But they do not work in eastern Kansas. And we are not far east of the center of Kansas. Sure does depend on the humidity in your area. I can imagine them being a great thing in Albuquerque, NM.

[Tom Clark FL]

I lived in Florida for 40 years, and had my shop air-conditioned. The bills were big. After moving to New Mexico three years ago a swamp cooler was installed in the 1300 sq ft shop. The cooling bill is a couple of dollars a month. What a difference. The humidity goes up from 20% to 30%, and actually feels great. It cools the shop to 75˚ when it is 95˚ outside. In FL the humidity never went below 50% even with the air running. Rust? What rust? As long as you are in a dry climate the evaporative coolers are wonderful. They don't work in humid locations.

[Charles Lent]

In the low humidity Southwest they can do very well if you can keep the larger droplets from being blown onto the machinery or wood. Blower speed is usually the problem. In higher humidity parts of the country, especially the Southeast, they are dismal failures. They work on the evaporation principle and the cooling comes from the evaporating water.
Any place where the humidity is above 30-40% they will just make matters worse. Only an air conditioner/heat pump can help you here. These work to remove humidity from the air as well as cool it.

Charley

[marty shultz]

I used one in AZ and it worked well. I only turned it on when I was in it. I did experience light surface rust but it wasn't a problem.

[Rich Enders]

We run evaporative coolers in our Phoenix, AZ factory and humidity/rust are certainly not a problem. They are good for a 10-20F reduction in factory temperature whenever the ambient temperature is high, and more importantly the humidity low. They are relatively inexpensive to operate, but ours seem high in maintenance.

You will need to check your local conditions (or HVAC professionals) to see if any/or what part of the year such a unit would be beneficial. If you experience humidity above 25-40% it may not be very useful.

[Peter Kelly]

Would tend to agree with the above. One of my exhibit vendors has swamp coolers in their shop in southern Utah. No rust on the CNCs or panel saw.

[Dok Yager]

I run both in my shop here in Phoenix. Swamp cooler until July or August when it gets humid and then change to A/C. No problems with rust or wood warpage but I`m sure that's due to the normally extremely low humidity most of the year.