Air Conditioning a Moreton Steel Building

[sroxberg]

I want to improve the air conditioning in my Moreton Steel Building. I currently have a 25,000 BTU window unit that keeps it from being crazy hot, but not cool.

The building only has a single layer of blue foam board so new insulation is required but I'm not sure how much that will help.

I also can't afford to insulate and put in new AC at the same time.

So I was considering adding ceiling insulation which I really don't have today. Would that help the AC? It would then help the heat this winter and then I could add extra wall insulation next spring.

Any thoughts from the group?

[EatenByLimestone]

I would work with air sealing the structure. After making sure the heated, or cooled air can't escape, I'd add furing strips and a radiant barrier. I'd cover this with foam. You can also get foam boards with the radiant barrier installed already.

[AlanBienlein]

I have a 24 x 24 metal building that I cool with a 25,000 btu window unit. I have 3/4" foam on the walls that has foil on one side and white plastic on the other. For the ceiling I used 1.5" fiberglass duct board. I can cool my shop to 75 in the summer no problem.

[Wild Turkey]

+1 on radiant barrier for the roof. I worked in an uninsulated/non-air conditioned building and by 2 pm in the summer the heat would drive me out. During the winter it was comfortable on sunny days, both due to radiant heat from the sun hitting the roof.

Upgrade the insulation and the current AC might be enough.

[sroxberg]

It has some blue foam board install on the roof and sides now but I can only see the inside, I'm assuming the outside is foil.

So would insulating the ceiling and eliminating the peak and access to the roof heat help. I'm assuming yes since it will greatly reduce the volume of air to be conditioned.

[Wild Turkey]

sroxberg said:

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I'm assuming yes since it will greatly reduce the volume of air to be conditioned.

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Fer shure

Just make sure to extract the hot air from above the rafters when you want to cool things down. In the winter you might want to pump it down to where you are.

[Estrogen Hostage]

Need to know size.

[sroxberg]

Sorry, I thought I posted the size.

30 by 45 and the side walls are probably 10 feet, 9 for sure.

a few small windows but north facing and two large garage doors that are insulated but don't seal the best.

[Estrogen Hostage]

Myself, I would spend the money on insulation and air sealing. Lots of energy goes to condensing the water in the air, leaking air brings in more humidity. You have two tons available which isn't much, but I am always surprised how little heat and cool is actually required in a well insulated building without windows. My neighbor has an 80x100 barn that is easily heated with an old heater from a house. I am always shocked by how little it actually runs. Terry might be able to help you with a manual J or better idea on what size is right, but I'd fix what you know is wrong and see if maybe you don't need to spend that money after all.

[J-W-P]

Absolutely more insulation. Especially overhead. My shop is about the same size but I put in a ceiling. I have 10' at the ceiling. I insulated the walls with fiberglass and loose cellulose overhead. I don't have AC. Your window unit will work a lot better if insulated better.