Shop is about done

Except for the internal wiring I'll do myself some time this year. I hope??? Anyway, has anyone here put air conditioning in a shop this size? Oops, the size of the shop is 40' x 50' with 16' sidewalls. I have an old wall mount unit from the days when we lived in a trailer house. I forget the btu but it's good sized. I bought it new in '95. The North and South walls are 8" and the west n east are 6 " with the East being the divider between the 50' x 60' cold storage side of the building. 

  Hello Lonn   With good insulation, paddle fans, some forsite,  and keeping the doors shut,  I think you can keep it comfortable.   I HAVE 1 !/2" styrofoam walls and ceiling, paddle fans, it stayed cooler until about 9:00pm this week.   Allen

When you jump over that line you might consider a couple of mini split systems.  I figured 2-3 ton systems for my 40 X 60 X 12' sidewalls, 3 insulated garage doors, 6" blown insulation in the ceiling and 7" bat insulation in walls.  I'm quite a bit farher South of you and not sure of what calculation for your area.

I was in one in south dakota a couple of years ago about that size, he had two window ac's and one did just fine most of the time. the building had spray on insulation with no celing (open all the way to the peak)

I've got a 48x67x14 w/concrete Morton with liner.6in wall bats,R 38 blown ceiling.We've been 100deg for almost 2 wks. Kept closed the whole time it's been 76-78deg but yesterday the humidity got to be enough that I gave in and opened the doors to get a breeze and work in the shade.Pretty sure a 24000 btu widow unit mounted in the wall would take care of it....just haven't done it. Don't usually have this much heat this long. Also never gets below 32 in winter with no heat with extended 0 temps.Have a little pot burner oil stove (no blower on it) that will hold 70deg if you want to run it on high.Ceiling fan helps w/heat.

Edited by SteveM C/IL - 06 Jul 2012 at 9:56am

Along the same lines as Stan's idea, I have heard of drilling 2 wells next to each other so the water would go into the same cavern it came out of. Of course, drilling a well is fairly expensive. We went to church with someone who cooled their house by burying water line through their yard and circulating it in a closed loop. Of course, they hooked it into their central air some way, but you could ged some radiators that were used in a house with a boiler for heat and circulate water through that. My friend has a setup that pumps water out of and back into a pond. It seems to work pretty well, but I think that the other methods I mentioned would be easier to maintain. Or, you could just use a plain old air conditioner and not mess with that fancy stuff!

I have AC in a 40 x 60 and open- system geothermal in the house. GO with closed-system geo if you can. Takes lots of trench in the beginning but us more economical in the long run.

Lonn-  if you haven't poured the concrete floor yet... pour it with PEX tubing inside... and lay down some 2" EPS foam underneath it FIRST... that buys you LOTS of options!

There's lots of good suggestions up there... a few things that should be noted-  an average 12,000btu (one ton) window air conditioner uses about the same amount of energy as a central air system of twice the size... and they become a big heat-loss point during the winter.

The problem with workshops, is variability- some guys lose lots of heating and cooling comfort through regular door open/closings.  Sometimes the building is in a spot where natural airflow can do most of the cooling, and sometimes the roof is so low that sunshine heats the building faster than anything can cool it.

Old timers would build high ceilings underneath the roof, so that roof heat would flow out naturally, and well overhead of the workspace.  Modern pole barns tend to be clear-span, with low pitch and low to the ground.  Even in my 1950-vintage pole barn, the roof edges are 10', peak is 15', and while the galvanized steel roof reflects lots of heat back up, it still gets silly hot, and radiates right down to the ground...  when I rebuild this thing, it'll get a whole lotta engineering, so it ain't an overgrown EZ-Bake Oven.  One silly thing I've done to cool down the pole-barn when I HAD to work on a hot sunny day... is put an ordinary oscillating sprinkler on the roof for a few hours... dumb trick but it works.  Water coming out the downspouts is HOT!

Back to cooling...  I put an addition all the way around our old house... the entire south side is a passive solar room that provides about three quarters of our home heat during sunny winter days.  The floor is black concrete 6" thick, with PEX tubing in it.  During the summer, the sun does not shine on this floor (I designed the roofline that way!), but when we're in the cooling season, I trickle well water through the floor tubing.  The cooling mathematics isn't complex- IF well water comes in at 58F, and comes out at 75F, so 17F change...  and flows at 15 gallons per hour (120lbs of water)... that means 120 x 17 = 2040 btu. Doesn't seem like much, but I basically regulate the flow to set floor temperature... if I crank up the flow, the outlet temperature drops, and the slab chills.  Right now, the slab is at 66F, and I'm barely trickling the water... have ceiling fans on the south porch, it forces cool air around the house envelope, so the central air system only runs about 50% of the time on a 100F day.

Running cooling water through a radiator works... but not as good as controlling the temp in the slab.  Bonus to cooling the slab, is that it can be hooked to the water jacket of a woodburning stove, and heat the floor in the winter.  Insulation under the slab keeps the shop dry, and heating/cooling costs low.

Lonn. I have a 30 by 50 all metal  very well insulated with a 5 ton unit can get down to 65 very easy my air man said it would down to 40. Lonn you have my phone # call if you want.  jim in MO..