Shop A/C

[prd2hnt]

I am going to put up a 40x60 polebarn this spring. Inside I am going to build a 20x20 shop.

I figure a small window a/c unit will be enough for the summer days here in NE. My question is can I mount the window unit so it's exhaust is in the pole barn itself? Id' llike to avoid having the hanging out the side of a new barn.

Thoughts?

Brian S, NE

[OldCarGuy]

No it would not be a good idea to have the working end of a window A/C unit exhausted in any enclosed building. The heat coming off the condenser will soon heat up that area to the point that it would overload the A/C's high pressure side and kick itself off. The unit must be mounted to get as much “outside air” as possible in order to be efficient.

[swgray]

Yes, it'll be ok. This is done frequently in industrial buildings. The area of the pole building will be 5x's bigger than the room being cooled.

You'll have to do something with the drain, though. Hose in the bucket, out the wall or (if you have one) your sink/floor drain. Depending where everything is located, you may need a condensate pump to get the water to where it needs to go.

[Stuart in MN]

I've also seen it done in commercial/industrial applications without issues. Like swgray said you'll have to deal with the condensation drain somehow.

[prd2hnt]

Thanks guys. I thought the rest of the building would be big enough to deal with the heat issue. There will also be a window near the a/c exhaust if necessary.

Working on the rest of the design, winter heat, high and shape of the work bench, location of the air compressor etc, etc etc.

Lots of fun. Can't wait till the weather warms up and the ground drys out.

Brian S, NE

[xtremes]

I have three units in my Car Audio shop blowing into the warehouse side. It does get hot in there but not to the point where you can't stand it. If it's really hot just leave the door open.

[roger55]

I agree that it will be just fine.

Your temperature in that barn will probably be cooler than the outside temp here in Austin, TX. My window unit is in the afternoon sun and I bet it gets near 120 degrees in the area outside of my garage on those 100+ summer days.

I did get the biggest window unit I could find and it is 240 volt unit (Heat/Cool) with 24,000 BTUs. I suggest you do the same. If you size the unit with a A/C sizing chart, you will be way undersized. You absolutely need to size your unit bigger than recommended for the square footage. Recommended sizes are for living space, not shop space. A lot more heat is generated in a shop that you need to compensate for. Shop lights alone generate a bunch of heat.

Also, you will want to insulate the area over the ceiling for sure. Insulating the walls and an insulated door would be a plus also but not near as important as the ceiling.

Another suggestion:
Spend a summer down here in east Texas. After that, you'll feel like you don't need A/C at all. Just get a fan and blow some of that dry NE air through your garage.

[krooser]

you don't need a/c in Austin....just get a roadster!!!!