Why You Could (But Shouldn’t) Use A Garage Air Conditioner


Anyone who spends a lot of time working in the garage knows it can become uncomfortably hot in the summer, especially here in Texas. Not only does this affect how you feel while you work in the garage, but many of the items that are stored out there, such as paint, collectibles and metal tools, are recommended to be stored in cooler temperatures than you are likely storing them in. Depending on where you live, the temperature in your garage may be hotter than recommended, or desired. Because of this, we often get asked if it’s possible to put an air conditioner in the garage, or if it’s even safe to do so.

The short answer is — Yes you can. And yes, it’s safe if done correctly. However, just because you can doesn’t necessarily mean you should. There’s a few reasons for this, which we will go into detail down below.

Even though we don’t necessarily feel that this is the wisest use of an A/C unit, here are the options that you have to cool your garage and how to do so as efficiently as possible.

3 Considerations for Garage Air Conditioning


If you chose to put an air conditioner in the garage, you should strongly consider adding some sort of insulation. Whether you add it within the walls or on the garage door itself, without insulation the air conditioner will essentially be ineffective. Or, perhaps the more accurate way to describe it, is a feeble and inept waste of energy and money.

This is because the cool air from your A/C unit will simply escape through the garage door or uninsulated walls and the temperature will only stay at a comfortable level for a very short period of time. This will ultimately lead to your air conditioning unit working harder than it should, which will do nothing more than raise your utility bills and shorten the lifespan of the unit.

Before we get into the various types of air conditioners to help you cool off your garage, here are three things you should keep in mind when buying an A/C unit for that space.

1. Proper Ventilation:

You’ll need to pick a place to vent your air conditioner – you can use an exterior wall, the garage door, or small glass windows. Or maybe you’re just one of those lucky folks that has a full-sized window in the garage. If you don’t have an area to vent it properly, you will need to consider installing the vent in an exterior wall, which will likely require you to cut a small hole in the wall.

Whatever option you choose, venting the air conditioning unit is necessary while it’s running, because the hot air that gets released needs to have somewhere to go, otherwise it will just go through the unit and right back into your garage. This will trump your efforts to cool the area. With a properly installed vent, the hot air can travel directly from the unit, through the vent and out of the garage.

2. Know the Size of Your Garage:

It’s also important to select an air conditioning unit that is large enough to provide enough cool air for your entire garage. You will need to determine the square footage and then compare it with the BTU rating of the unit. A higher BTU rating means that the unit will be able to eliminate more hot air from a larger space in a shorter amount of time. To help you figure out how many BTU’s you’ll need for your garage, you can use our Cooling Capacity Calculator.

Commercial Portable Air Conditioners

Because most garages have lots of open space, little-to-no insulation and high temperatures, you should consider buying an A/C unit with a higher BTU rating than you initially think you need. This will allow the air to cool faster, and put less strain on the unit itself. It won’t be the silver bullet to cooling a garage, but it will certainly help.

3. Consider a Commercial-Sized A/C Unit:

While they have a higher initial cost, commercial A/C units are made with rugged, heavy-duty and sturdy materials. These units are specifically designed for warehouses and factories, where an air conditioner is not necessarily feasible or cost-effective. These units may be your best bet at cooling a hot environment, such as a garage.

Is A Garage Air Conditioner Worth It?

Obviously, the answer to this question will vary from garage to garage, and person to person. For many people, it may simply not be worth the time, money and effort to install an air conditioner in the garage. For others, this may be a life-saver that makes your day-to-day more comfortable.

No matter what scenario you find yourself in, ask yourself these three questions when you are trying to make your decision on whether it’s worth it for you:

  1. How hot does it get where you live?
  2. How many hours do you plan on spending in the garage each day?
  3. How many months will you have to deal with the warm weather?

If the temperature outside often gets extreme in your area and you plan on spending a lot of time in your garage, it may be worth the effort to install some type of cooling device in your garage. If you don’t spend much time out there, it may be easier to just get a simple fan to keep the air circulating around you.

Your Options:

At this point, let’s assume you’ve decided that it is worth installing an air conditioner in your garage. Now, it starts to get interesting. There are many different types of air conditioners and they all have their pros and cons, and the fact that it’s going in your garage only makes this decision more complicated.

1. Window Air Conditioners

If you have a window in your garage, this type of air conditioner may be your best option. This is especially true if you have a smaller garage.

Window air conditioning units are usually inexpensive and easy to install. They have directional louvres allowing you to direct the cool air to the specific area you will be working in. While these units are bulky and possibly somewhat noisy, they are an affordable, quick option for cooling small garages.

Once you have the window A/C installed, you can safely shut the garage door, turn the unit on and allow the unit to do it’s thing. You will start to feel the temperature drop to a more comfortable level pretty quickly.

2. Portable Air Conditioners

In order to avoid wasting money and energy, it’s wise for portable air conditioners to meet certain conditions and be installed properly.

We would not recommend using one in your garage at times when the temperature goes above 90°, especially if your garage is not properly insulated. It will merely provide short-term relief and over-work your A/C unit causing it to burn out quickly.

While portable air conditioners are great for indoor and residential use, they may not be the best option for the garage. It all really depends on whether you have a way to properly vent the unit.

If you don’t have a window that can easily vent the unit, you will need to consider installing a vent in an exterior wall. This will likely require you to cut a hole in the wall. If you have to go to these lengths, it may just be best to install a thru-the-wall air conditioner, as they are usually cheaper and don’t take up floor space.

Portable air conditioners have the ability to lower your energy use and save you money. But, if your garage doesn’t have a spot to install a vent for the device, it’s hard to recommend one of these for the garage. Especially if it’s not properly insulated.

3. Mini-Split Air Conditioners

A mini-split air conditioner is another cooling option worth considering. As the name suggests, this type of air conditioner is split between the inside and outside. They are appealing as a garage air conditioner because they don’t require ducts and are known to be extremely energy efficient. They are also mounted high up on the wall, allowing your floor space to be preserved.

The main downsides of mini-split air conditioners is that they are more expensive to buy, an also need to be installed by a certified HVAC professional. These two factors may be a deal-breaker for you. Not only do they drive up the overall costs, but you will still need to insulate the walls and garage door to get the true efficiency and savings these air conditioners offer.

When all is said and done, it may not be worth the time, money and effort that goes into installing a mini split in your garage. If you work out there every single day, then maybe it’s the best option. Otherwise, the initial cost may prove to be too high to justify the purchase.

4. Dehumidifiers

The unexpected cooling solution for your garage, actually isn’t a cooling solution at all. Sometimes, the high humidity levels of a garage makes it feel hotter than it really is, which is why a dehumidifier is a great option to consider.

Using a dehumidifier can help remove moisture from the air, leaving your garage feeling cool and dry. While they don’t lower the actual temperature, but can feel 5 to 10 degrees cooler because the relative humidity is reduced. They are cost effective, portable, and impermanent solutions for a hot garage.

Another benefit of using a dehumidifier in the garage, is that they can be used in conjunction with one of the other cooling options mentioned above. Some air conditioners even come with dehumidifying capabilities installed as a feature. This is something to consider when deciding on whether or not you need to cool your space.

Too Long, Didn’t Read?

Can you cool your garage with an air conditioner? Yes. Should you? Depends on your situation.

If you decide you want to use an air conditioner in your garage, we would recommend you also go out of your way to make your garage as energy efficient as possible. Otherwise, you will just be throwing money away.

Jeff Flowers

About Author

Jeff Flowers has been a self-described beer geek for over a decade now. When he's not chasing his daughter around, you can usually find him drinking a fresh brew and wasting too much of his time on both Google+ & Twitter.


  1. JoJo says

    Dehumidifier? to cool? WRONG!!! It uses HEAT to dry the air, you will lower the humidity but you will also raise the temperature.

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