Is a Mini Split Good for a Garage? (Best 5 for Garages)

Garage typically don’t have an HVAC system. If you’re thinking of a way to heat and cool your garage, you might think of a mini split system. But, is a mini split good enough for a garage?

In short, mini splits are good for garages. Mini splits are powerful enough to provide adequate heating and cooling to a garage. Not only they’re very energy efficient but also operate incredibly quiet.

Although mini splits are a relatively simple HVAC system, there are a few important things to consider when buying and installing one in your garage.

Why Mini Splits are Good for Garages?

If you want to heat and cool (air conditioning) your garage, what options do you have?

  1. Extend your existing ductwork
  2. Use a portable air conditioner
  3. Use a window air conditioner
  4. Use an electric heater in winter
  5. Use a mini split system

First, extending your existing ductwork seems like a neat idea. However, it is very costly to do that. In addition, your existing HVAC unit (air handler and condensing unit) may not have sufficient capacity to accommodate the additional floor area.

Second, you can use a portable air conditioner to cool your garage. But, the problem with portable air conditioners is they are very loud. Besides, there are not many portable air conditioners that do well in heating. So, you have limited choice.

Third, you can use a window air conditioner to heat and cool your garage. However, window air conditioners are not powerful enough for a garage, not to mention your garage have poor insulation or not insulated at all.

During winter, you probably use an electric space heater to keep yourself warm in the garage. This is a simple and effective solution but the problem is electric heaters are not efficient and very expensive to run.

Or, lastly, you can use a mini split to heat and cool your garage. Compared to modifying your existing HVAC system, a mini split system is a more cost-effective HVAC solution. Besides, mini splits are only $300-400 more expensive than portable air conditioners and they do very well in heating.

On top of that, mini splits are much more energy efficient than any other HVAC systems:

Mini Splits are More Efficient than Other HVAC Systems

Mini splits are much more energy efficient than central air conditioners. A standard mini split has a SEER rating of around 20 while a typical central air conditioner is around 16 SEER. Hence, it is 25% more efficient, not to mention mini split doesn’t have any energy loss due to duct leakages.

The reason why a mini split is so much more energy efficient has something to do with its form factor. 

Compact air conditioners such as portable/window air conditioners are generally not efficient because they’re not allowing more space within themselves for efficient heat transfer. Mini splits consist of two separate units. Together, they have more contact surfaces for efficient heat transfer.

High-efficient mini splits can go up to 30 SEER but they cost a lot more at the same time.

Mini Splits are Much Quieter than Other HVAC Systems

The best thing about mini splits is they are extremely quiet. Both their indoor and outdoor units run very smoothly. You can assure that you can have a peace of mind in your garage.

A standard mini split creates about 20-25 dB of noise at the indoor unit and around 45-50 dB of noise at the outdoor unit. Some mini splits are noisier but all of them are generally considered as very quiet.

On the other hand, portable/window air conditioners are often hovering around 50-55 dB, making them a few times louder than a mini split unit.

With the mini split run at low fan speed, you can whisper to each other. When a mini split runs at high fan speed, you still can have a normal conversation without having to yell at all.

As for the outdoor unit, when it starts to run, it is quite noisy if you are near. After about 15 minutes, it will ramp down and so, the noise will be reduced significantly.

Can a Mini Split Heat and Cool a Garage Well?

Having a mini split in your garage will keep your garage cool in summer and toasty in winter. Mini splits are able to bring the temperature in your garage down to 75°F (24°C) when the outside temperature is at 95°F (35°C).

The outside temperature may drop to 32°F (0°C) in the winter. A standard mini split heat pump is able to keep up and maintain the temperature in your garage at 75°F (24°C). Keeping your garage warm and toasty. Most mini splits are able to cool effectively up to an outside temperature of 115°F (46°C).

If you are living in extremely cold states such as Alaska and North Dakota, the average temperature during winter may hover around 0°F (-18°C) or 10°F (-12°C) which is beyond the effective working temperature of a standard mini split.

A standard mini split can lose half of its heating capacity when the outside temperature drops to 17°F (8°C). Therefore, you’ll need a mini split that is designed to work in extremely cold weather conditions and this type of mini split is often called the arctic mini split or some other names depending on the manufacturer.

You’ll have to check the operating temperature of the mini split in the manufacturer’s specification sheet to confirm. If you have an arctic mini split, it is able to maintain your garage temperature at 75°F (24°C) even when the outside temperature is at 0°F (-18°C) and below.

When the outside temperature drops below the freezing point of water, the mini split outdoor unit gradually freezes up, causing its performance to drop. But, the mini split will boost its heating power to accommodate that. You’ll hear a louder noise at the outdoor unit when it’s pushing the limit.

However, the mini split outdoor unit will eventually come to a point where it is no longer able to work with all the ice on its coil. Then, it’ll stop heating for a few minutes in order to perform defrosting. Afterward, it’ll go back to heating like normal.

Some mini splits stop working to defrost while some mini splits use an auxiliary heater to defrost. Mini splits that use an auxiliary heater to defrost are able to continue to provide heating without having to stop for a few minutes. Thus, they provide much better comfort but at the expense of higher electricity consumption.

Though arctic mini splits are able to work when the outside temperature is below 0°F (-18°C), they are running at about 50% efficiency only. The colder the outside temperature, the less efficient they are due to the frequent defrosting process.

How to Choose the Right Mini Split for Your Garage?

Choosing the right mini split is very important. Here are a few important things to consider when buying and installing a mini split in your garage.

Mini Split Capacity

Most garages are not well insulated. If your garage is not insulated at all, I suggest you insulate it first. Else, you’re going to need a big mini split and your energy cost will increase significantly.

For insulated garages, I suggest using 30-35 BTU per square foot size the mini split for your garage, considering the garage have more air leakages as well.

Normally, mini splits are sized based on 20-30 BTU per square foot. However, this is for well-insulated houses that have minimal air leakages. For garages, you’ll need a bigger mini split to maintain the temperature.

Below is the recommended mini split size for different garage sizes (insulated garages):

Garage SizeGarage AreaMini Split BTU
1-Car Garage250 sqft9,000 BTU
2-Car Garage350 sqft12,000 BTU
3-Car Garage700 sqft24,000 BTU

A 1-car garage is typically about 250 sqft. A 9000 BTU mini split is enough to provide adequate heating and cooling in the garage. If the garage is not insulated at all, a 12000 BTU mini split is recommended.

If you have a 2-car garage, the garage size is about 350 sqft and thus, a 12000 BTU mini split is needed. If the garage is not insulated, I suggest you get a 15000 BTU mini split.

For a 3-car garage with a floor area of about 700 sqft, two 12000 BTU mini splits are recommended. You may use one 24k BTU mini split but two units will give you a more even cold/warm air distribution. For an uninsulated 3-car garage, the recommended mini split size is 15k BTU x 2 units.

Going up or down one size is not much of a problem for mini splits because they have an inverter or variable-speed compressor which allows them to regulate their capacity and keep your garage at a consistent temperature.

Mini Split Operating Limitations

Mini splits are officially rated at a fixed operating condition. Meaning the capacity, power consumption and efficiency of a mini split are based on a certain indoor and outdoor temperature.

The standard operating condition of a mini split is known as AHRI rated condition and the condition is as follows:

Cool Mode

  • Indoor temp.: 80°F (27°C)
  • Outdoor temp.: 95°F (35°C)

Heat Mode

  • Indoor temp.: 70°F (21°C)
  • Outdoor temp.: 47°F (8°C)
  • Outdoor temp.: 17°F (-8°C)

So, if the outdoor temperature is 95°F (35°C), a mini split that can bring the indoor temperature down to 80°F (27°C) is a full 9000 BTU unit. If the indoor temperature is set at 75°F (24°C), the actual BTU of the mini split is slightly lower (eg: 8500 BTU).

That’s usually not a problem at all. But, the real concern here is when you want to use a mini split to heat your garage.

Most mini splits stop working when the outdoor temperature drop to around 5°F (-15°C). That’s not a big issue because you’ll avoid the cold anyway. But, the problem is as the outdoor temperature drops, the heating capacity of the mini split drops as well, which may lead to insufficient heating.

Therefore, if you want the mini split to perform well in cold climates, you’ll need to choose a mini split with a good low ambient heating performance (see below listed mini splits).

5 Best Mini Splits for Garages

With the above criteria, I’ve shortlisted a few mini splits that are suitable to be used in a garage. Here are my top 5 mini splits for garages.

Daikin 17 Series

Capacity: 9k, 12k
Efficiency: 17 SEER, 9 HSPF
Garage Size: 250-350 Sqft
Price Range: $1100-1400

Why Choose This: Quality & Reliability

Daikin is a Japanese brand known for the quality and reliability of their mini splits. Daikin mini splits run exceptionally smooth and quietly. If you want something that can last for a long time while also maintain in a good shape after several years, this is a good option.

Senville AURA

Capacity: 9k, 12k, 18k, 24k
Efficiency: 22.5 SEER, 12 HSPF
Garage Size: 250-700 Sqft
Price Range: $1100-1600

Why Choose This: Low ambient heating

The AURA series of mini splits by Senville is designed to handle heating in cold climates. It is also known as arctic mini splits. The lowest outdoor temperature which this model can still perform is -22°F (-30°C). Pretty impressive huh? Consider one of these mini splits if you’re staying up the north.


Capacity: 12k, 36k
Efficiency: 22 SEER, 10 HSPF
Garage Size: 350-1000 Sqft
Price Range: $1700-2600

Why Choose This: DIY installation

MRCOOL is famous for their DIY mini splits. Their mini splits come with all the necessary instructions and accessories for an easy DIY installation. If you’re a hands-on person, this mini split can save you a thousand dollar by not having to hire a technician for the installation.

Mitsubishi ‎MSZ-HM

Capacity: 9k, 12k, 18k
Efficiency: 18 SEER, 10 HSPF
Garage Size: 250-500 Sqft
Price Range: $2300-3200

Why Choose This: Serviceability

Out of all mini split brands, Mitsubishi is the most popular in the United States. Hence, many technicians know how to fix one of these mini splits. Besides, spare parts are also widely available. So, Mitsubishi mini splits are worth considering if you don’t want to deal with the after-sales hassle.


Capacity (115V): 9k, 12k
Efficiency: 19 SEER (Good)
Price Range: $550-600

Why Choose This: Lowest price

ROVSUN 9k and 12k mini splits are one of the cheapest mini splits on the market. They’ve just recently been available and I believe they use their price advantage to penetrate the market now. So, if you don’t mind the slightly reduced efficiency, this is a very affordable option.

More on Garage Mini Splits

Here are more information on mini splits and garage applications.

How Much Does It Cost to Install a Mini Split in a Garage?

A standard mini split costs anywhere between $1000 and $1700 to purchase. If you need a professional to help on the installation, it’ll cost anywhere between $300 and $1500 to install. Factors such as where you stay, where you want to install and do you need additional electrical work will affect the final installation cost.

Can You Install a Mini Split by Yourself?

Although many people install a mini split in their garage by themselves, it doesn’t mean that it’s easy. But, I assume you are a hands-on guy and you are ready to make it happen.

Almost all mini splits come with an installation kit including refrigerant pipes, drain hoses, cables and accessories. With a 3.5″ hole saw cutter, you are able to install a mini split in your garage within a day.

However, most mini splits don’t include an outdoor unit mounting bracket for you to mount it on the wall. So, if you want to put the mini split outdoor unit on the wall (it does look nicer on the wall), you’ll need something like this DuctlessAire universal outdoor mounting bracket that is adjustable.

If you get the Daikin 17 Series which I recommended, you don’t have to buy an outdoor mounting bracket separately because it is included in the package.

Nevertheless, if you decided to put the mini split outdoor unit on the floor, make sure you prop it up using a concrete plinth or some sort of a base that can support the weight of the outdoor unit (~70 lbs).

Just to show you, this Senville ground stand is what you need for the outdoor unit. But, seriously, it is expensive and I don’t think you need such a nice ground stand.

Besides, most people mount the outdoor unit on the wall.

Also, don’t forget to check if you have any nearby power outlets for the mini split. Most of the time, a single phase 230V power is required to be connected to the mini split condenser.

Then, using the communication cable that comes with the mini split that connects the indoor and outdoor unit, it is able to power the mini split air handler.

Nonetheless, I suggest you get a professional to install so that you don’t void the warranty. Most manufacturers don’t warranty anymore if their products are not installed by a professional HVAC technician. So, be careful.

How Far Can a Mini Split Be From the Condenser?

Most mini split air handlers can be placed nearly 100 ft from their condenser. However, most of them are pre-charged with a refrigerant enough for 25 ft only. Beyond that, you’ll need to charge in an extra amount of refrigerant which often requires a professional to do.

A mini split purchase typically come with 16 ft refrigerant pipes and cables. So, you can expect to put the condenser about 10 ft away from the mini split air handler.

Where is the Best Place to Put a Mini Split?

Most of the time, the best place to put a mini split in a garage is on the wall where the condenser is mounted behind. It’ll make your installation work faster and easier.

One thing to consider is to try not to let the mini split blow directly onto your body while you’re working in your garage cause it’s unhealthy. Anyway, you can always adjust its airflow direction by setting the air swing.

I’ve covered exactly how high and where to put a mini split (both the indoor unit and the outdoor unit) in my post Best Place to Put the Mini Split Air Handler and Condenser. I suggest you check it out especially for the outdoor unit location. I’ve included some diagrams as a quick guide for the positioning of the mini split.


A mini split is a great heating and cooling solution for a garage. The most important thing is to get the right mini split capacity for your garage. If you are unsure, get a professional to assess your garage and have them install the mini split for you.

If you need me to help with your HVAC system, consider my Email Consultation service.

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