So when we redid our house a few years back I had R-30 blown over the garage and an insulated garage door put in so I could eventually A/C my garage.(i have one 7ft wall I need to insulate still, but that is easy)

It is 600sqft.. so i know ill need at least 14,000btu of cooling.

The downside is I dont have any way of using a wall mount system, and if I did a split, the condenser would have to go on the roof.. and that makes the price jump exponentially... so my question is.

Anyone use one of the portable ones in their garage?  Does it get the job done or is AZ just too much for those.. even the ones rated to cool your square footage?  Do I need to one size up to deal with our extremes?

The BTU you listed should be ok but it's hard to tell when just using rule of thumb.  You'd really need a heat load calc done to be sure.

Why would the condenser have to be roof mounted if you went with a mini-split?  Block wall or HOA stuff?  I'm not sure why it'd change the price all that much either.  Either way you still have to run the lines, electrical, mounting, etc.

With the portable kind you are talking about you still need some way to vent the hot air so you'd have to account for that.

If I put the condenser outside ground level, it would either be on our patio and displace a chair at our table or out in the front of the house, on the side, blocking the drive to the RV gate.  Same with a wall unit, it would get in the way of our tiny patio area or stick out into the drive.  I can easily punch a 5-6" hole in the wall or door for exaust for a portable unit.

I mean I could run lines to a condenser to the other side of the house.  We have a roof package heat pump for air for main house... Why roof made most sense.  Buy a small split is gonna run $1500 plus probably.. a portable will be 400-500.

Any reason you couldn't mount the condenser unit for the minisplit up high on the wall?
High enough you could work around it?

Edit: one split I looked up had a condenser unit that measured 30.3 x 11.8 x 21.8 Inches

That thought did cross my mind.

It would go up high there then come down the wall into the garage side..  
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Photo of from Google Earth.. I do not have our Christmas lights up lol.

Lag bolt some brackets to studs make a shelf, Bobs your uncle, you got an AC unit.

I have an enclosure in one bay that is insulated, however has generous plexiglass windows and a plastic strip curtain for the entrance.  Its at most about 2/3 of a garage bay.  My portable AC is about 14k BTU.  I have a booster fan to supply additional fresh air to its intake.

If I let it run for about an hour before I enter, its bearable perhaps without a tshirt during the hottest times of the summer.  Early June I let it run for a couple hours, it gets to a nice 76-78 degrees at the coldest point near the AC.

I don't think a portable AC is going to cut it for 600 sq ft.   I think the big issue is that the garage or my shop area is full of dense objects that retain a lot of heat.  Cabinets, tool boxes full of tools, etc...  you try to cool down the place and all of things are giving off radiant heat at 98 degrees.  I think it would be near impossible to have too much AC cooling given the uphill battle we are waging.  I wish I had gone with a split system or at a minimum the biggest wall unit I could find.

You would have to start cooling the night before to fight the heat soak... including floor.  Im betting once you get it down to temp and leave it running it would possibly do OK.  But then you'd have to let it run all summer and those fans never turn off from what I understand... just the compressors.

They get pretty small!  Looking at them now.

The big downside on a portable unit is most are 110v.  I had a heat pump go out on a 2 month old new unit once.  The problem was to keep the warranty, I had to replace the compressor with a OEM unit.   There were none in Phoenix and its JULY.   We had to wait a week to get one in (They said Calif, But I think it came from Japan).    Needless to say, I really didn't want to lock the house up and move into a hotel, so I rented a nice portable unit.  I closed off part of the house which meant that I only needed to cool the Kitchen, Family room + office/bedroom (est 900 sqft).  It did a great job and kept the rooms reasonable.   But I used enough electric power during that week to cool the house for a Month.  OUCH !  I figure you 600sqft could be done, but I don't want to see the electric bill.

I did a window unit in my  3 car garage a few years back.  Its 220v 24k btu and it will in July cool that entire area down to less than 80 in about 35 minutes.  The good news is that it can easily handle bringing a HOT vehicle in, but cannot keep up when you bring in 2 cars that are hot.

Having done this twice.. Once w/ a portable unit, one with kind of a ghetto wall unit.. The energy expense is not worth it.

Both places were adequately insulated, but I don't spend hours per day out there, so it didn't make sense. You pretty much have to set it up so it blows cold air on you. That's fine if you are out wrenching on things, or doing woodworking stuff.

That was causing some problems for me reloading, because the air flow was fucking w/ the electronic and manual scales. So I was still sitting there sweating.

Plus only a few nights a week out there max added about $100 monthly to my APS/SRP bill.

First of all, I didnt read all the threads, but if that is your house, why not just mount a window unit above the door frame. It wont affect parking, it wont affect the RV gate, and if it doesnt work out, all you have to do is replace some drywall and some paneling.

I wish.. there is not enough room there between the top of the door and the roof inside.  I have a framed dry-walled ceiling in the garage since it used to be a car port in its previous life.

I just did this, and my setup is identical to yours. I put a mini-split on the wall just below the attic vent. That allowed the lines and electrical to run inside the attic to the wall unit inside.

Look into the MrCool DIY mini-split sold at home Depot.  Cheap and you can install it yourself. I've been happy with mine so far.

If you intend to drive a hot car in ,get the big one .Your APS bill will take a hit ,but if you want to stay cool in the desert your going to pay.

Yes, I don't use the big door at all. It's just like part of the house now, not for vehicle storage. I use it as shop space for projects and stuff. Will eventually have a mill and lathe.

You'll want a 230v unit for efficiency if you can get the power to it. Likely the cheapest method is going to be a very large window type unit, cut into the side wall. You don't need any kind of shelf as others have mentioned but you will need to do some framing around the unit. That's what I did at my old house with a 25x25 garage and within one hour it was good enough to do just about anything in, after a few hours it was really nice inside.

Leaving it running all the time will kill your power bill. Even insulated doors suck in comparison to a full wall.

They do make hanging brackets for mini splits and if you didn't know, most mini splits come charged and ready to run long as the line set length meets your requirements. You might want to consider a heat pump unit as well if you want it usable all year, they aren't much more.

This is relevant to my interests.

Anyone try a portable swamp cooler?