Shop Cooling

[sawkerf]

Do any of you guys use an evaporative cooler unit to cool your shop? I was thinking of adding one to compliment my 20,000 BTU window unit. I'ts way undersized for my 2000 sq ft building (metal pole barn, in the south, no insulation in the walls). As you can tell I need to add something to cool things off a bit. The AC alone will keep the temp around 78 - 85 in the hottest part of the summer, and boy does my power co. love that! Any input will be greatly appreciated. Thanks, Kip

[Brady Watson]

Kip,
Evaporative coolers don't work very well in high-humidity areas. Arizona ~ great...Louisiana bijou...no dice.

-Brady

[fleinbach]

Even though your 20,000 BTU air conditioner is undersized to cool 2000 ft.² there are two things that will help quite a bit. The number one thing is to seal all cracks and crevices. Even small leaks will degrade performance. Then add blanket insulation. Another thing that degrades performance is if you have a vacuum system that exhausts to the exterior. Mine does not.

My shop is 640 ft.² and I cool it with a 8000 BTU air conditioner. It is well insulated and stays quite cold even on the hottest days.

[dvanr]

If you already have aircon don't stick in a evaporative unit.

You have to remember an evaporative cooler works on the principle of waters latent heat. Water evaporates, it sucks up heat , condenses it releases heat. If you air condition a room and introduce an evaporative cooler your net gain is zero. The evaporating water cools the air , and when the moisture laden air gets to your aircons cooling coil it condenses releasing the heat.

[gene_marshall]

You guys have AIR CONDItioning IN YOUR SHOPS?

GEEEZ! I'd worry about the dust.

[bleeth]

That's what filters are for Gene. Try working without it in my neck of the woods.
Dave

[davidallen]

contrary to earlier opinion, I've found that evaporative coolers work well as auxillary cooling. they will make the air more humid and this will put an additional load on your AC compressor if you recirculate the air. most shops I've seen are fairly open with a decent exchange of air with the outside. if you're losing cool dry air you might as well lose cooler damp air. the makeup air (from the outside) will decrease the load on your compressor due to humidity from the evaporative cooler.

I have a small evaporative unit to cool my cubicle at my day job. for some reason, the room's temp is set between 75 and 78. I turn it on and it blows 70 deg air as long as I keep it wet.

you might also look at putting a water misting system on the outside of your building. metal pole barns can be effective solar collectors. removing the heat before it gets inside may help more than an additional cooler. you could use a temp sensor (thermostat) on the exterior of the wall to control a valve for that section so only the hot walls (and roof) would be misted and only as needed to cool them down.

da

[sawkerf]

Looks like I'll get another 20,000 btu AC and put it on the other side of the shop. The new 500 sq ft is insulated all around and I plan to insulate the rest one day (it'll never happen).All this stuff as already crossed my mind, I just needed affirmation. I couldn't imagine that adding more humidity to already near 90% - 100% humidity could be very effective. Thanks for your help. Kip

[arundo]

I would try an exhaust fan or a few of them up as high as possible. The next step would be to have the air inlet as low as possible from the shady side of the building. That spot will change from am to pm. If there is an attic, that needs to be well vented. And an exhaust fan installed to get the heat out. The roof fan that I installed in my house was the best money I ever spent. Keeping the attic cooler helps the ac work more efficiently.

Like the post before said. With AC if you do not insulate you’re just wasting your money to the electric co.

[btk]

Kip,
Another option might be a Ductless Mini Split System (heat pump). They work great in closed in areas witn no windows (i.e. basements). You do have to put the Condensor outside.

http://www.mitsubishielectric.com.sg/aircon/residential.asp
Cost approx $850-$1250 depending on BTU's and are relatively easy to install.

[gerald_d]

Step no. 1: Paint the outside white.

[mikejohn]

Insulation is nearly always the long term economic solution. Hewever, it has to be designed right. A metal building with metal pillars can have a 50% reduction in the insulation capability if you simply fill in between the pillars.
Leave the door open for any length of time, or insufficiently fill gaps and then insulation is a waste of time and money. (but there again, so is any cooling/heating method)
.........Mike

[Denny Jahnz (Unregistered Guest)]

My shop is just under 4000 sf and I have one wall mounted air conditioner to cool it. I used to have 2, but did some remodeling and insulating and it wouldn't work there anymore but since it is alot tighter I don't think I will miss it.