Cooling a 40'x40' Shop, ideas needed

[DENALIAKITAS]

Hello all!
I am new here and just starting my new shop. Its 40x40 with a 12' wall. I have the heating figured out (passive solar with small makeup gas heater) but i have to have it air conditioned in the summer. The shop will have 3 inches of closed cell spray in foam insulation so it will be rather well insulated even compared to most homes. My old shop was only a 24x24 and i simply used a window ac unit. That is simply not an option for this new shop. Anyhow if anyone could offer some advice on what type or size of unit to use i would be appreciative. Thanks

PS, the shop will have a ceiling in it and the spray foam insulation will be applied on top of that so that the rafter space is not heated/cooled.

 

[Charles (in GA)]

Putting your location (at least your state or province) in your profile would help others. What kind of summer time temps do you experience? Humidity? What type of roof, color of roof, etc.

Charles

 

[green.bubbly]

Mind me asking what that 3' of closed cell will cost you?

I am not an AC guy but how much time you spend in there and how cold you want it to be will come into play. I am putting a 12,000 btu in my fairly well insulated 24x24 which is undersized but I will not be in there everyday and I do not need it to hang meat in there.

 

[DENALIAKITAS]

Putting your location (at least your state or province) in your profile would help others. What kind of summer time temps do you experience? Humidity? What type of roof, color of roof, etc.

Charles

I am in Kansas. We often hit 100 degrees or better in july/august. The roof is steel and white in color and we see pretty high humidity. Thanks

 

[DENALIAKITAS]

Mind me asking what that 3' of closed cell will cost you?

I am not an AC guy but how much time you spend in there and how cold you want it to be will come into play. I am putting a 12,000 btu in my fairly well insulated 24x24 which is undersized but I will not be in there everyday and I do not need it to hang meat in there.

It will run about $1.80 per square foot of coverage.

 

[skipnsb]

In some private hangars I have seen flexible ductwork hanging from the ceiling with a couple of light guy ropes to move it around and hold it in place wherever you are working, such over an engine to change spark plugs. Gives a directed area of coolness.

 

[semi75]

Wow 3 inches of closed cell, I rarely hear more than 2 inches.

 

[badgerboiler]

Find a professional to size the load using a Manual 'J' program for cooling and heating.

He will need the all dimensions, of walls, floors, ceilings, doors, and their quality - insulation. The quality of garage doors - insulation and seals - can be a large factor in heating and cooling loads. Traffic will also factor in, though less in private garages.

You may consider ventilation in a private garage also as the door may not be open often and air quality will suffer - don't for get the CO detectors. A specify an energy recovery ventilator for larger shops.

Also consider a mini-split heat pump for your garage. With up to 25 SEER, heating, cooling and dehumidification comfort for you and you tools is better assured.

 

[paris_tj]

I got a 30x40x10 with a 24k btu mini split, and it works well. With the higher ceiling and being a little larger I would guess 36k would be in the ballpark. I am no a/c expert though.

 

[Charles (in GA)]

I got a 30x40x10 with a 24k btu mini split, and it works well. With the higher ceiling and being a little larger I would guess 36k would be in the ballpark. I am no a/c expert though.

The OP's shop is 19.200 cu/ft

You shop is 12,000 cu/ft

The OP's shop is 60% greater in cubic volume than yours.

Food for thought.

Charles

 

[Deltarat]

My 30x50 not that well insulated, I have 2-24k window units mounted in the wall. Today it was 100* with heat index of 110* and it was 80 in the shop, but I opened the roll up door 3 times and brought in a hot car.

 

[bobadame]

Blow cooler night air into it so that your morning starting temperature is lower. Your end of the day temp should be a bit lower.

 

[mrpowderkeg]

Yup cool night is FTW! Basically what you want is a way to bring in cool night air from down low and vent out hot air from the ceiling. However you do it such as a few bathroom exhaust fans to **** out hot air, and a few intake fans to bring in cool air, perhaps have them come on at 2am and shut off at 5am?