A/C Advice

[FixItDan]

Hey everyone, it seems that this is a great place full of support and encouragement which is not really something that is common in the world of garages and I love it.

So I just purchased a new 3 car garage in Phoenix as part of our winter home and now I am having to adjust to living in Arizona instead of cold Alberta. I love it, the only thing is that I have probably lost 10 pounds sweating in the garage just getting to the car and getting out. This place needs an air conditioner and I am pretty much clueless about that. In all seriousness, the only A/C I had in Alberta was in my car so this is a bit of a jump. I need something to cool the 1200 square foot garage, and if possible I would like it to have some sort of humidifier on it so the garage doesn't get too dry. What can you all recommend? Pretty sure I need something that will attach to the wall at this point, or maybe a really big ground one.

Any suggestions are welcome. I am pretty lost in this topic and I don't like the shop near me (neighbors told me some bad stories already) so if you could give me some brands or even better specific models that would be amazing. Thanks in advance everyone.


I went and talked with the guys at one of the HVAC companies around, and after talking with him for a while he suggested that I get a 24,000 BTU mini split as it will give me the ability to do work in the shop as well. It was a little out of the budget I had planned, and this guy again made a great suggestion that I find a good used A/C unit, and he pointed me towards https://www.for-sale.ie/air-conditioning-unit which had lots of mini split units that were bought and could not be returned even if it was just the wrong size. I got mine now though, and the garage is feeling soooo nice.

 

[Fixin'Stuff]

Is the garage insulated? Insulation for the ceiling, walls and doors is the first step. A/C doesn't lower humidity much in Arizona, simply because there isn't much for it to remove to begin with.

Do you want the garage comfy enough to work in, or just comfy enough to not have a heat stroke when you get in/out of the car? My dad's attached garage in Central Texas was insanely hot on summer days. I took a look and found that there was zero insulation in the attic over the garage. Had him have some fiberglass blown in and the difference made the temp comfortable enough for him to not be sweating from head to toe every time he got in or out of the car. He didn't work in the garage, so didn't need A/C out there, but keeping the attic heat in the attic dropped the garage temp enough that he could bear it.

 

[6768rogues]

Cheap: window shakers. Low cost, easy to install if you have windows and electric. Sometimes banned by subdivision rules.
Good option, more money: Mini split. Out of the way, quiet, efficient.
More money: Condensing unit with air handler. Harder to put out of the way. Good filtration, quiet, reliable, easy to service.

 

[FixItDan]

Is the garage insulated? Insulation for the ceiling, walls and doors is the first step. A/C doesn't lower humidity much in Arizona, simply because there isn't much for it to remove to begin with.

Do you want the garage comfy enough to work in, or just comfy enough to not have a heat stroke when you get in/out of the car? My dad's attached garage in Central Texas was insanely hot on summer days. I took a look and found that there was zero insulation in the attic over the garage. Had him have some fiberglass blown in and the difference made the temp comfortable enough for him to not be sweating from head to toe every time he got in or out of the car. He didn't work in the garage, so didn't need A/C out there, but keeping the attic heat in the attic dropped the garage temp enough that he could bear it.

It has been insulated, so that is not a problem. I am wanting to have it comfy enough to do some work in, I will have my laptop out there to work on contracts and what not.

 

[Fixin'Stuff]

Have a look at a few of the mini-split threads here. Lots of good info there. They cost more up front than a window shaker, but they are near silent, ramp their speed up and down to only provide the amount of cooling/heat needed, and sip electricity once the room is near the set point.

 

[FixItDan]

I'll take a look at those, thanks. I figure I can at least bill some of it to the business so a big upfront cost isn't too bad, plus the silence would be nice.

 

[Black Oak]

Any windows facing south or west ? Solar gain in AZ. can be a big factor in properly sizing your choice. My first thought is mini-split.

 

[cnttxmdc]

I'm not sure what your budget is, but what I ended up doing was buying a used package unit (compressor, condenser, evaporator, blower, etc. all in one box, outside) that was removed from a commercial building. I negotiated the unit itself down to $350, and ordered a fabric duct system for air distribution inside. For ducting it from the unit to inside the building, I encased R8 flex duct inside of sheet metal duct (for better aesthetics, and to protect the flex duct). It works great for me, and cost under $1000 to fully air condition a 30x40x14 shop.

Just food for thought, and what worked for me....

 

[justinjoyal]

If dust/dirt/debris will not be common and you dont want ducts, the obvious best way to go is mini-split.

Once you figure out what kind of insulation you have and can calculate the cooling load you can size your system accordingly.

For 1200 sq ft I'd go with two heads on a single condenser.

 

[ford33]

Call a couple of local HVAC companies out and have them recommend a solution. Make sure they calculate the size and not just guess.

They are familiar with climate and can size a unit properly for you.