Edited to add - I cannot use a window unit or mini-split system. The walls are all concrete block. Unless I want to cut through the block walls (which I do not), it's either a portable unit or nothing.

I want to get a portable A/C unit for the garage. I am going to get a De'Longhi unit from Costco, mainly because of Costco's amazing return policy just in case anything goes wrong with the unit.

I have the choice between two units. One cools 500 sq ft and is $399. The other cools 700 sq feet and is $499.

This unit will go in a garage in Orlando, FL. The garage door is insulated. The walls are all cinder block. I do not expect this unit to bring the garage down to inside the house temps of 76-77 degrees, but just take the edge off when it is 90+ degrees outside and at least make the garage comfortable for short stretches of time.

The garage is right at 500 sq ft, 20'x25'. Should I get the unit rated for this? Or should I get the larger one, with the thinking that since it has more power, it will work less and therefore last longer?

This message has been edited. Last edited by: holdem,

I have an 8x8 office in my garage, the walls are insulated and a 14k btu portable ac barely cools it to 78 in the summer. I think I’m on my fifth one so I’ve tried different brands too. A portable unit will not cut it, well unless you spend a few grand on a commercial version.

Of the two I would definitely get the larger one.

You didn’t mention if you have any insulation in the attic. If you don’t that will give you the biggest bang for you buck. You can rent a blowing machine at Lowe’s or HD when you buy the cellulose insulation. Be sure to get enough to blow at least 12”..

Roof insulation is key.

BUT, the blower vent units don't cool the amount of square feet they say they will. Go with the 700 SQ unit. A window unit is A LOT more efficient and better as you're not sucking warm air from outside to blow it out of the dryer vent.

Get the 700 unit. Bigger is better to not strain the unit. God Bless

They are more money but if the garage has an exterior wall, you might consider one of those wall mounted AC/Heater units. I have one made by LG. It works by a handheld remote. My garage is attached and the same size as that of the OP. My unit cools in summer and heats in the winter. Makes for a real comfortable mancave.

 
We have one (bought before we discovered mini-splits). Not sure of the brand or size. It doesn't do squat for cooling even a guest room. It cools you fine if you direct it to blow on you only.

I've had two of these and they all stink, they barely do anything.

You may want to reevaluate before you spend the money. Is there any way to put in a wall or window unit? Those actually work far better than any of these portable AC units.

I have also tried portables and had zero luck. Couldn't tell any difference at all in the temps when they were running. Figure out a way to go mini-split or window unit.

I'd use a PTAC unit. Way better than portable. You will need to cut 1-2 studs and set header and Jack's for it as well as run 240v circuit to it. May get to be kind of pricey in the end.

When our AC went out a couple of years ago in the middle of August in Texas we bought a Hisense unit for Lowes (or maybe HD).
It kept us alive for a week.
It was somewhere around $4-500 at the time - 120000btu.
Moved it to the garage after the new house AC.
It is a bit loud and you need to route the exit air with the vent.
However, it is effective.
Not a bad unit.
YMMV

Mini Split!!!!!

Granted we get all 4 seasons here and lots of humidity. But it heats, cools, and dehumidifies all in the same unit.
For 500 square feet you are looking around 1k total if you install yourself. Which installs are quite easy.

Hope to get one come tax time next year for my shop.

quote:

Originally posted by Black92LX:
Mini Split!!!!!

Granted we get all 4 seasons here and lots of humidity. But it heats, cools, and dehumidifies all in the same unit.
For 500 square feet you are looking around 1k total if you install yourself. Which installs are quite easy.

Hope to get one come tax time next year for my shop.

That’s what I want but I don’t have any open breakers for the power.

quote:

Originally posted by mrvmax:

quote:

Originally posted by Black92LX:
Mini Split!!!!!

Granted we get all 4 seasons here and lots of humidity. But it heats, cools, and dehumidifies all in the same unit.
For 500 square feet you are looking around 1k total if you install yourself. Which installs are quite easy.

Hope to get one come tax time next year for my shop.

That’s what I want but I don’t have any open breakers for the power.

Super easy solution, call an electrician. You can usually add tandem breakers to most panels and free up space, or you can install small sub panel. It should not require ba whole new panel, unless you otherwise already need a new one.

At work we use a 16.8k btu unit to cool about 300 sf of office space. The office is our control room, and all it has in it is one or two engineers, and four computer tower units with screens. 16.8k is sufficient, but we're in the middle of a climate controlled building. Two 7k units is not the answer you're looking for, but I have a hard time believing that a 7k btu unit will do anything for you except generate a higher electric bill.

i hear most complain about the portable unit. I have a bigger Sharp model from costco. Really started using it a couple of years ago. Once we got it ironed out it works really good for a smaller space. We have pretty low humidity though. Not perfect, but I like mine well enough to drag it out and hook it up once a year

With the heat in Orlando and Florida in general I would get the largest I could find. I know, until last year I had lived in Florida almost all my life and had a workshop in the garage and the AC was about as big as you could get in a window unit. It ran at the coldest temp possible & barely kept up.

I don't think you'll be satisfied with the performance of the portable unit. I tried a 14k btu unit. Installed a 24k btu window unit, it keeps it moderately comfortable; meaning it can remove about 15 degrees. Granted, on a hot summer day, 80 is a lot better than 95...

I'm in Georgia, YMMV.

I have a 900sf detached garage/shop. I'm in northern AZ so it gets darn cold in the winter and warm in the summer. I had a mini split installed when we bought this place. It's the perfect solution for my needs.

The HVAC guy used some type of a formula to determine the BTUs I needed. I thought larger would be better. He said HVAC is one of those situations when larger isn't always better. It has to do with efficiency of the unit.

Had two of the Costco units, two different brands.

Both were trash. Took them to a recycle place and got $20.

Only portable units I have seen work were big commercial used in a data center.