Which Air Conditioner Type is Best for a Garage? (1,2,3,4 cars)

Mini-split ACs are the best air conditioner type for garages. In this article, we’re checking three different air conditioner types: portable, window, and split ACs.

For a garage, you should not shortcut your air conditioning. Here’s why:

Quick answer: Mini-split ACs are the best type of air conditioner for garages. They provide enough cooling power, don’t consume any floor space, and don’t need any windows for installation. A good mini-split unit will last you for decades if you take care of it.

Let’s have a look at each air conditioner type in more detail.

Which type of portable air conditioner is best-suited for garages?

What do we want in a garage air conditioner? First and foremost, it should cool the garage during the blasting summer heat. Looks are secondary. Ideally, a garage AC should not occupy any space (which is limited in garages).

So, without further analysis, here’s my personal recommendation:

Recommended mini-split AC for all garage sizes

I recommend this Mr. Cool mini-split AC (click here to view it on amazon), which comes with a full DIY kit and requires comparably little installation work.

This AC is a real AC system that takes no shortcuts. No weird window setups that block the entire window from opening.

This mini-split AC is perfect for garage owners who like to do things themselves (which I assume most of you are). 

Why do I recommend this exact model? The cooling capacity of this split AC is 18,000 BTU, which is high enough to cool down even large garages with attached workshops. It also has a heating mode to keep you warm in the cold season!

And the installation of this split AC is easy and requires no professional training. All you need to do is pass one pipe through a wall. So, you will have to cut a total of just one hole.

That’s something anyone can do. And that’s why I recommend this model.

Now, technically, in terms of energy efficiency or cooling capacity, it is no better or worse than other split AC units.

I just liked the simple installation and the cooling power. If you already have another split AC lined up, then go for it!

Which types of AC can you install in a garage?

Let’s have a look at the three different types of air conditioners you can use in a garage.

Mini-split AC

The mini-split AC represents the regular kind of AC that we know. One component of the unit is located indoors, while the compressor unit is located outdoors.

Not only does this reduce the noise, but it is technically superior to other air conditioner types. The heat extraction process of a split AC takes place outdoors. The cooled air is blown indoors.

This separation is necessary to achieve good efficiency and high cooling capacity. Because when an AC extracts heat from the refrigerant indoors (which portable air conditioners do), then we have the issue of making sure the heat does not reenter the room.

With a split AC, this is technically impossible.

Mini-split ACs are objectively the best air conditioners for garages. They don’t have any efficiency problems. They don’t occupy or even block windows (such as portable or window ACs). And they don’t take up floor space (such as portable ACs).

Also, they are very slim, as the large component is located outdoors. With a window AC, you would have half of the AC taking up space in front of the window.

Mini-split ACs are reliable, they need only little maintenance, and therefore, will last you a long time. You’ve probably seen garages with split AC units multiple decades old.

That’s why I would always opt for a mini-split AC.

Window AC

Window ACs are suitable for garages with large windows and lots of space.

They consume quite a lot of space in front of the window. And they need just as much, if not, even more, installation work than a split AC.

The reason is that you have to set up the window construction to hold it in place. And then, you will have to insulate the window properly. For some window types (such as tilting windows), you would even have to remove the entire window for installation.

In the worst case, the window AC will barely fit into your window and block off all of the sunlight. And who in the world wants to sacrifice his last garage window?

To say something positive, window ACs have an efficiency just as good, or almost as good, as split ACs, if they are properly installed.

The reason is that half of the AC is located outdoors. So, the refrigerant heat extraction takes place outdoors, and you don’t have the issue of heat reentering the room, that portable ACs have.

Also, window ACs provide very high cooling capacities that match those of split ACs. The cooling capacities go up to 30,000 BTU or more, which is a lot more than what you’d need for your garage anyways.

I’d say you should get a window AC only if you rent your garage and you are not allowed to drill holes through your garage walls. But if you get a window AC, then measure the dimensions of your garage window first and ensure that the window AC fits the window.

In almost any other case, I’d highly recommend getting a split AC instead. 

Portable AC

You can use a portable AC in a garage. Even in a garage without windows, you can install a portable AC by drilling one venting hole through the wall.

If you absolutely need to get a portable air conditioner, read my recommendations for the best portable air conditioners for garages.

However, efficiency-wise portable air conditioners can’t keep up with mini-split units or window ACs.

Also, you will have to regularly drain the accumulated condensate from the AC, which can get annoying.

You can build yourself an automatic drain by connecting a drain hose, and (if necessary) a drain pump. However, this requires a lot of installation effort. And why not use your energy to install a split AC instead?

On top of all of that, portable ACs waste precious floor space in your garage. You can expect an average portable air conditioner to block at least 16 square feet of floor area.

A split AC will block none.

Here’s a forum quote that I liked:

“Don’t waste your time on a portable unit. They are garbage. Punch a hole through the wall, and get a through-wall unit.”

Which AC type is best for different garage sizes?

A mini-split AC will be the best air conditioner type for all garages. For most window ACs you will need to account for some extra space, as the window AC will occupy the window and block the area in front of it.

A portable AC will occupy the largest space and is, therefore, only suitable for larger garages, where it won’t be able to supply enough cooling power.

To find the best-suited air conditioner cooling capacity for your garage, I used standard garage sizes. Assuming you need 20 BTU per square foot, you get the following results:

Garage sizeGarage AreaCooling Capacity (BTU)Best AC Type
1 car garage240 – 384 sq. ft.4,800 BTU – 7,680 BTUsplit or portable
2 car garage440 – 624 sq. ft.8,800 BTU – 12,480 BTUsplit, window or portable
3 car garage620 – 816 sq. ft.12,400 BTU – 16,320 BTUsplit or window
4 car garage800 – 1056 sq. ft.16,000 BTU – 21,120 BTUsplit or window

The AC type recommendations are based on the cooling capacity of the ACs and the available free space.

For example, a 1-car garage will usually not have enough space in front of a window to support a window AC.

In a 2-car garage, all AC types are suitable.

For larger 3 or 4-car garages, split or window units are the best type of air conditioner, as they have a large cooling capacity suitable for large spaces. Portable ACs would not be able to cool these large spaces efficiently.

Which air conditioner is best for a garage without a window?

For a garage without a window, a split AC is the best.

A window AC would (obviously) be the worst choice as there is no window to fit it. You can, technically, install a window AC without a window. But that’s a stressful and highly suboptimal thing to do.

Portable ACs are suitable for garages without windows if you can set up the AC through a drilled hole.

But this rarely makes sense. Especially considering that you can get a regular split AC unit where you will have to drill a hole anyways. And you won’t have to deal with all the disadvantages (bad efficiency, space blocking, low cooling capacity) of portable air conditioners.