900 sq ft building (AC)

[feelergaugephil]

Cant afford it this year,,,, (yeah Im sweating as we speak) but I have a newly build 30ft x 30ft building (900 sq ft) which is heavily insulated, including the roof...
Only thing thats not is the 18ft roll up door.
Im not looking for ice rink temps, but enough for the awful humidity/heat here in Louisiana...
With that said, what AC brand and B.T.U,s (if thats correct) am I looking for?
I probably go with one that I have to cut a hole in the metal side of building.
Thx in advance..

 

[Speedy!]

I'm in the process of having a 24x34 shop built and the AC contractor is recommending a 15,000 BTU PTAC (packaged terminal air conditioning) unit. It is slightly undersized for the space which will mean it'll run a tad more and keep the humidity down. You may want to look for an 18,000 BTU unit for yours as mine is a tick over 800 sq ft. I have a 15,000 BTU unit in my current 3 car attached garage that is 20x32 and it does a nice job of cooling the garage in summer temps even when it's near 100 out and also does a good job heating in the winter.

Another option is a ductless split mini unit. I'm going to bounce that off my AC contractor as well to get his input vs. the standard 15,000 BTU PTAC unit.

 

[CNGsaves]

^ ^ ^ This. Go a little bigger as your Baton Rouge humidity and heat will likely be longer portion of year, and need to run quite a bit.

Look for highest SEER rating that you can afford to keep your PoCo electric bill down.

 

[feelergaugephil]

Thank you guys.

 

[nine4gmc]

I would check around locally before purchasing anything, the humidity is really different here than other parts of the country making it harder to cool. I had a 24k btu ac unit in my old shop along with an 18k btu in the office, the office would stay cool with the door closed but even with both running the shop would not get cool at all. My electric bill was through the roof for a few months before I finally cut a hole in the wall and just used an extraction fan for pennies a day. It was about the same temp with the fan as it was with the ac but a couple hundred dollars cheaper electric bill.

You are lucky with the insulation, my new shop is 900 sq ft as well but totally uninsulated. I stuck an extraction fan in here but rarely use it as I mostly work at night now when it's cooler.

 

[justinjoyal]

900 sq ft but how high is the garage and does it have large windows ?

 

[Falcon67]

CNGsaves and nine4gmc have it. Having lived in Houston for a few years, I'd also recommend a 2" condensate drain.

 

[miketyler]

I think 12k and 15k would both be light for that space. Many contractors use the 1ton per 500 sqft rule. It a cheap guess like throwing horse shoes but works for many cases. That said, there are variations in construction, climate, orientation to the west that can run that number up or down. Go to www.eComfort.com and fill out their load sheet and let them calc it for you. Its free. If the space is as bare as you say I bet you are going to be over 20k heating.

 

[Jackfre]

How is the shop used. Are the doors frequently opened, re-charging the warm moist air or do you get in there and drop anchor. Big difference in product selection based upon your answer. For the drop anchor type I'd go 18-24. I think a 15 would be light there.

 

[Joeys79]

I'm working on a 28x34. Walls are up and insulated R13, but no ceiling, (8 ft), at this point (planned metal with R30). I put a 22,000 BTU GE in the wall. It actually keeps things cool without the ceiling in yet - cold air falls, but I have to be getting a lot of loss. I opted for the 22k rather than 18k because I seem to remember the 18 was borderline with 1000 sq. ft. I also have 2 ceiling fans to eventually go in to help circulate. Sam's Club was a hair under $500 out the door. For me a split was a little to pricy, and not sure how much I'lll be out there in the dead of winter. I'm happy so far and it should be great after everything is buttoned up.

 

[pseudorealityx]

Another hint.... lower temperatures will mean higher relative humidity levels. Keep the space at 78 and it'll run at a lower RH% than if you try to keep it at 70.

 

[pseudorealityx]

I would check around locally before purchasing anything, the humidity is really different here than other parts of the country making it harder to cool.

Baton Rouge is about the same as Charleston, SC , southern GA and Alabama, most of Mississippi, etc in terms of humidity.