Whether your garage is finished or not, you might find that it’s difficult to maintain a comfortable temperature. While you can always add layers, you can only take so many off…unless you’re into that sort of spiritual garage experience.

Keeping your cool

We have a look at 5 of the best mini split air conditioners. Some come equipped with their own unique additions but their role remains the same: to condition the air and keep you cool.

We’ve also included a buyer’s guide since purchasing a split air conditioner can be a complicated decision. There’s more to it than you may think.

 Friedrich M09CJMitsubishi MY-GL12NALG LS090HXVPioneer WYS SeriesSenville SENL-09CD
Heat PumpNoNoYesYesYes
Energy StarYesYesNoNoNo
BTU9,00012,0009-11,0009-36,0009-15,000
SEER21.523171715
Temp Range64-86° F57-90° F60-90° F62-90° F-
Coverage400+ sq ft500+ sq ft400+ sq ft400+ sq ft400+ sq ft

Friedrich M09CJ

Friedrich enjoys the fact that they’re an air conditioner manufacturer and nothing more. Their only focus is A/C units and that’s what sets them apart from the competitors. The M09CJ is a powerful little unit that runs on a standard 110v power source.

With an output of 9,000 BTU, this is ideal mini split for a two-car garage—or space up to 400 square feet. However, this model does not come with a heat pump, so it’s only capable of chilling a room or simply running a fan.

If you live in a warmer climate, namely one where you’ll only likely need to chill the room for a good portion of the year, this is a dependable unit with a high SEER score and Energy Star compliance. It comes with Inverter Technology, which allows for the compressor to operate at variable speeds. Units without a variable speed compressor are either running or not. And constantly shutting down and kicking back on can burn a lot of excess energy.

In all, you’re paying about $1000 for a cooling-only unit, but its SEER score of 21.5 and built-in technology will consume much less energy in the long run compared to other units in this article. So while the upfront price may come off as steep, it will pay for itself after a few years of use.

It has a distinct auto dry feature that allows the indoor unit’s coil to dry out by running an internal fan after shutting off. This cuts down on rusting or deteriorating internal parts from excess moisture.

Other amenities include:

  • 24 hour programmable timer as well as sleep timer
  • 3 cooling modes: auto, cool, fan
  • 4 fan speeds: quiet, low medium, high
  • 4-way auto swing louvers, allowing for movement in all directions
  • Dehumidifying mode
  • Surge cool

The Surge cool feature allows for the the unit to run at 100% for 30 minutes. In order to get a 400 square foot room comfortably down to temperature, it can take some units up to 90 minutes for the cool air to permeate throughout the space—depending on the quality and factors of the environment.

With the surge cool feature, it’s like running your car’s A/C at the max setting to get the temp down as quickly as possible. Very useful if you don’t have time to wait for the temperature to go down.

The unit will also automatically restart in the event of a power outage and comes with washable, reusable filters. Yet another feature that cuts the operating costs down. The Friedrich M09CJ has constantly been noted as a very quiet unit. Sometimes prompting owners to physically check that the unit is in fact running.

Common complaints

This split air conditioner does not come packaged with a refrigeration line. It’s suggested that you either purchase a 15-30′ line package or advise your HVAC installer to supply their own.

The instructions aren’t terribly clear, so unless you’re experienced in mini-split air conditioner installation, I wouldn’t waste time trying to make sense of the instructions. Rather, spend that time looking for a qualified HVAC installer.

Documents and manuals

Mitsubishi MY-GL12NA

This mini split air conditioner is a bit stronger than the other units we review. Again, this unit has only cooling capabilities but it sports a larger output of 12,000 BTU, which would be ideal for a larger space (500 square feet) or three-car garage.

Coupled with its Energy Star compliance and SEER rating of 23.1, this unit is highly efficient and will pay for itself faster than less-efficient models in this list. It does not come with a heat pump so again this air conditioner will only cool or run the fan.

Since the condenser unit must remain outside and exposed to the elements, any added coatings or processes to protect the hardware can help with longevity of the unit. The Mitsubishi line of mini splits come with a Blue Fin coating.

This is a very thin protective layer that is sprayed over the condenser fins. It won’t affect operation but resists adhesion of dust and dirt. Very helpful if you live in a harsh climate where temperatures are very low.

This mini split air conditioner comes packaged with a remote offering Mitsubishi’s Smart Set functionality, which simply means the remote remembers cooling profiles (temperature, fan speed, airflow direction). This can be useful if several different people use the space or you will be working in the garage right next to the unit as opposed to across the room.

This unit is also compatible with Mitsubishi’s kumo cloud™ app, providing the ability to control the unit via wifi from any device with the application installed. Ratings on the app leave much to be desired, so consider this a valuable addition at your own risk.

It’s been noted that the maximum noise output is very low (45 dB) for both the condenser and the inverter. The fan is incredibly quiet and sometimes you have to feel that it’s running because of its very low sound output.

Common complaints

Aside from the waning praise on the cloud application, there isn’t much to say about the quality of the MY-GL12NA. This mini split system must be installed by a licensed contractor with an EPA Refrigerant Certificate to qualify for warranty. There are a lot of moving parts so better to have the long-term warranty be valid in the event of unit failure.

With its higher output, it also requires running on a 208-230 volt line. If you don’t have a supply

Documents and manuals

LG LS090HXV

LG’s single-zone, ductless air conditioner comes with a heat pump for year-round comfort in areas where your garage or living space is susceptible to very low temperatures. The compressor can operate in temps as low as 14° F and as high as 118° F.

The cooling component has 9,000 BTUs of output and the heating has 10,900. Both ideal for small rooms or garages around 400 square feet. As far as energy efficiency goes, it’s not as green as other models. It does not share an Energy Star certification and the SEER rating is 17. Keep in mind that the minimum SEER rating is around 13 (depending on your region) so this isn’t exactly pushing the limits of inefficiency but isn’t a gold medal winner either.

Speaking of gold, this model sports a Gold Fin coating similar to Mitsubishi’s Blue Fin to combat corrosion. The properties are similar and they provide the same protection. There isn’t any difference other than the color.

The louvers are controlled electronically. And along with the automatic fan speeds, these features allow for more natural air flow. Similar to the nature mode on pedestal fans, they distribute air in multiple directions while also adjusting the fan speed to feel like a natural breeze. These modes are referred to as Chaos Swing (horizontal airflow) and 4-Way Auto Swing (both horizontal and vertical airflow).

The LG LS090HXV comes with a remote control for added convenience complete with holster and mounting hardware. It provides a sleep mode, 24-hour on/off timer, and automatic restart in the event of a power outage.

Documents and manuals

Pioneer WYS Series

The nice thing about the WYS Series is that Pioneer offers a wide selection of BTU output for both 115 and 220 volt power supplies along with some impressive amenities. The model we recommend is the 9,000 BTU version with a 115 volt power source. This should easily adjust the temperature of your garage or 300 square foot space and hook right into one of the available outlets. No Energy Star compliance and a SEER rating of 17.

The WYS Series provides cooling, heating, dehumidifying, and ventilation (fan) all controlled by a remote. The heater mode has a vacation setting and automatic switchover from cooling to heating if set to automatic temperature management. It includes a timer and internal memory for remembering preferences you set.

One mode that sets it apart from other mini split models is the Night mode. This setting automatically adopts the temperature settings to the naturally changing body temperature levels during the night. So if this unit is being placed in a bedroom or addition in the garage where people plan to sleep, this unit will keep the room extra comfortable.

This model doesn’t have quite the low end capability compared to the other models in this list. It bottoms out at 62 degrees while the majority of other mini split systems can get to 60. But a couple of degrees at that low of a temperature is trivial in my opinion, unless this unit is planned to be used in a server room where temperature was critical.

The WYS Series have an automatic restart in the event of a power failure and can also be controlled via wifi if the extra dongle is purchased and installed. It comes with everything needed for installation, which includes a 16 foot insulated copper supply line.

Common complaints

The temperature LED is set behind the plastic coating. This provides a nice, sleek way of displaying the temperature without any other ugly components. The drawback is that it displays any time the unit is restarted or the temperature is adjusted. The problem here is that in a dark room, it’s quite bright. So you have to manually hide the temperature LED if you find it annoyingly bright.

Other owners remarked about a loud noise at startup, but that isn’t uncommon for mini split systems. If you’re in a noise-sensitive environment e.g. people sleeping or recording audio, consider this caveat. Otherwise, it’s not going to make much difference in a garage or game room.

Also, the louvers can’t be adjusted in heater mode. They are connected to a servo that controls them automatically. It’s advised against to adjust them by hand.

Documents and manuals

Senville SENL-09CD

Senville has a good reputation in the air conditioning category. In fact, just like Friedrich, mini splits are their main focus. The SENL-09CD is a great entry-level ductless air conditioner that will cool a garage very effectively.

This model does come with a heat pump that outputs around 15,000 BTU. The cooling side puts out 9,000 BTU, so it will work for a two-car garage. Although, it might take running it for about 90 minutes to completely cool the space.

The SENL-09CD has the worst SEER rating of all the models we looked at. It’s at the very bottom with a rating of 15. This model also does not sport the Energy Star compliance. Other models from Senville, however, do offer this compliance. It’s not very efficient.

If you’re still interested in Senville products, they offer an Energy Star compliant mini split with a SEER rating of 25. The AURA series can be found here.

This model does boast a “virtually silent” indoor unit under their Whisper technology. This is important for noise-sensitive environments—bedrooms, studios. It also has a Silver Ion Air Filtration system and built-in dehumidifier for better air quality.

Common complaints

In order to validate the warranty, professional installation is required. The instructions aren’t very clear but perhaps that’s done on purpose to dissuade DIY installation. A few owners noted that the first point of failure are the motherboards.

Buyer’s Guide

Want to know more about ductless (mini split) cooling systems? We put together a quick guide to help you get informed on the technological topic.

The 4 pieces of a mini split air conditioning system

Condensing unit: The condenser is the unit that will sit outside of your garage or room. The refrigerant inside cools the air and sends it to the indoor unit.

Refrigerant lines: Also referred to as line sets, these connect the indoor unit to the condensing unit outside. Refrigerant is “locked” inside the condenser until it is released after proper installation.

Delivery unit: For ductless air conditioners, this is the unit that is either mounted to the wall or installed in the ceiling (as a cassette). The delivery unit will provide the cool (or hot) air flow throughout the room.

Remote control or thermostat: This unit will allow control over the entire system. Some mini split systems have both a thermostat with full control and a remote with limited control.

Advantages of a mini split air conditioner

Noise level: Unlike a window mounted A/C, which has the condenser attached to the fan, the condenser is located outside of the garage or home. On models with Inverter technology, the motor only runs as much as is needed by the room being cooled or heated. With some models, you may not even realize it’s running.

Zones: If you see models with multiple zone capabilities, what they’re referring to is how many delivery units it can support. For a garage you may never need more than one. If you’re cooling an entire house, however, a multi-zone system is recommended. The advantage of having these individual units is that they are all independent and can either be completely turned off or set at their own temperature.

No ductwork: By having no ductwork in between the condenser and delivery units, you’re eliminating quite the homeowner headache. Not only do ducts eventually leak or deteriorate, but they build dust and allergens that are spread throughout the house. Mini split (ductless) systems are the perfect marriage of central air and window units.

Ugly windows: It looks so tacky when half of a window is taken up by some plywood for the exhaust line. Portable air conditioners require that the hot air be expelled outdoors and that’s typically through a window. With mini split air conditioners, you only need a hole cut in your wall no larger than the diameter of a coffee mug.

Single-zone and multi-zone systems

If you’re looking to cool a garage or other small space under 500 square feet, a single zone air conditioner will suffice. These are also great for room additions in homes that already have central air conditioning but are inaccessible to the ductwork.

The only difference between single and multi-zone systems is the amount of delivery units that can be supported. Distance is not a factor so secondary and tertiary zones can be installed several rooms away or on different floors. You have to keep the amount of refrigerant and line-length in mind when determining placement.

Size and power

Check out the BTU chart to determine the output necessary for your application. For garages and small bedrooms anything 12,000 BTU and below should be sufficient. But this is also dependent on the average ambient temperature and how well your garage is insulated.

If your single or two-car garage is poorly insulated but is within the guidelines for a 9,000 BTU unit, you’re going to find that it’s working harder and longer to keep the temperature down. By the same token, if you get a unit that has a much higher BTU rating than is necessary, and is in the same poorly insulated garage, you’ll find that it’s turning on and off frequently which dramatically shortens the life of the unit.

Another reason why you don’t want to buy an over-powered unit as because it may leave excess moisture in the air. Air conditioners remove both heat and humidity from the air. If the unit is too large, it will cool the room quickly, but only remove some of the humidity. This leaves the room with a damp, clammy feeling. A properly sized unit will remove humidity effectively as it cools.

Refer to the chart for the right size to purchase but know that you need to have a well-insulated room for any air conditioner to work efficiently.

When looking at multi-zone systems, make note that there will be a total BTU rating for the entire system and a per-unit BTU rating for each delivery unit. For example, a three-zone mini split air conditioner with 21,000 BTU will most likely have 3 delivery units with 7,000 BTU each. That 21k isn’t applied to a single unit.

Square footage of your spaceBTUs needed (per hour)
150 to 250 sq. ft.6,000 BTU
250 to 300 sq. ft.7,000 BTU
300 to 350 sq. ft.8,000 BTU
350 to 400 sq. ft.9,000 BTU
400 to 450 sq. ft.10,000 BTU
450 to 550 sq. ft.12,000 BTU
550 to 700 sq. ft.14,000 BTU
700 to 1,000 sq. ft.18,000 BTU
1,000 to 1,200 sq. ft.21,000 BTU
1,200 to 1,400 sq. ft.23,000 BTU
1,400 to 1,500 sq. ft.24,000 BTU

Installation

Some ductless air conditioning manufacturers require the complete installation by a licensed HVAC professional for the warranty to be valid. Others will only require that an HVAC pro sign off on the installation. Be sure to check with the manufacturer’s guidelines if you plan to DIY install your mini split air conditioner. The reason for this is the refrigerant included in the condenser requires a license to handle.

Delivery unit placement

Mini split delivery units are quite easy to install and can be placed essentially anywhere with access to the refrigerant and power lines. They’re essentially hung on brackets and plugged into the wall. Make sure they are placed in the most efficient location in your garage or room.

Power source and voltage requirements

Some units only require a 110 volt system to run. This is the common voltage for American homes so you’ll have an easier time finding a power source to tap into. You should note, however, that some units require a dedicated line in order to run safely. Again, since this is a common voltage, it shouldn’t be too big of a job for an electrician to address.

There are also mini split air conditioners that require a 200+ volt system. If you’re fortunate enough to have an extra 220 power source in your garage—maybe you moved from electric drying to gas—then that line can be used for the A/C. Again, you should check whether the model you have requires a dedicated line or can be placed on the “appliance” line.

IMPORTANT: If you’re uncertain about voltage requirements and what you have running in your home or garage, consult a professional. Incorrect voltage use can cause problems with both the unit and/or circuit breaker and ultimately cause a fire.

Energy efficiency

Depending on your available options and the space you’re looking to cool, mini split air conditioners can save you money in the long run and efficiently cool your home. There are two values that measure a unit’s efficiency: The Seasonal Energy Efficiency Ratio (SEER) and less commonly the Energy Efficiency Ratio (EER).

The SEER rating calculates the average cooling output a unit provides versus how much energy it consumes, when it’s run in accordance with the kind of yearly use patterns typical in average homes. The higher the rating, the better energy efficiency the system provides.

The EER rating is calculated by energy usage per square foot of cooling. The EER will be lower than the SEER. Before 2015, the minimum SEER rating in the Unites States was 13.0. Now, that value can vary per location.

When you’re pricing out models, the estimated yearly cost should give you a good idea of how long it will take to recoup your costs. The higher the SEER rating, the lower your yearly cost should be.

Some ductless air conditioners are so efficient that they have the Energy Star compliance rating. You’ll also find that units with this achievement are also about 50% more expensive than other, non-Energy Star compliant models. Depending on your anticipated usage, it might make sense to get the most efficient model. Some can pay for themselves after a few years.

Inverter and rotary compressors

Inverter type compressors have the ability to moderate their speed and output. This is important for 3 reasons: energy consumption, noise output, and unit life. By only running at the minimum speed, it uses the least amount of power possible to cool or heat the room. This also lowers the noise output as it’s not running on full and keeps it from constantly cycling on and off.

Rotary type compressors are simply on or off. There is no in-between or power grading. This acts just like a centralized forced air unit cooling down until it passes the thermostat, waiting until the temperature raises a couple degrees, and then running again, etc. As with the higher SEER and Energy Star compliance, you pay extra for the inverter feature but it does extend the life of your mini split air conditioner.

Operation modes

If you read through our reviews, you’ll find that there’s more to ductless air conditioners than just cooling air. Some have the capability to heat or dehumidify the air. This is especially important if you live in a location with actual seasons or perhaps in a more tropical environment. A few models make it very easy to stay comfortable all year long.

Heating: Mini-splits with built-in heat pumps work just like a central forced air unit in a home. It can be changed from cooling to heating with the flip of a switch. Some models, such as the Pioneer WYS Series, provide an automatic switchover function if the temperature moves from needing air conditioning over to heating.

Dehumidifier: This is an important option if you live in a tropical environment or plan to install in a basement. Dehumidification mode pulls moisture from the air as it runs by keeping the coil’s temperature below the dew point.

Fan only: This mode simply runs the fan with no added cooling or heating. This would be useful in instances where you’d simply like to keep the air in the room moving. There isn’t much comfort this can yield if the temperature is above or below the low 70’s.

Automatic: Automatic and Comfort modes will allow for the unit itself to measure ambient temperature and adjust the output accordingly. Models like the Senville SENL-09CD come with a remote that you can carry with you. A thermometer in the “Follow Me” remote measures the temperature near you and reports it back to the mini split computer.

Sleep and Natural modes: Similar to Automatic, the Sleep mode keeps the ambient air at a very comfortable temperature, ideal for sleep. Natural mode mimics the feel of a cool breeze by moving the fan at variable speeds.

Additional features

Cloud control: No, it doesn’t give you the power to manipulate cumulonimbus in the sky. This is a new technology, similar to what Vivint and Nest provide, where you can remotely control your mini split air conditioner.

Programmable timer: If your unit doesn’t come with cloud control, you can fall back on programming it to run at different points throughout the day. If you’d like it to heat first thing in the morning or cool down the room 30 minutes before you get home from work, the programmable timer will allow for that. Make sure your model has a 24-hour timer, such as the Friedrich M09CJ.

Adjustable airflow: In some models, airflow can be managed with a remote. Others will require you to manually adjust the louvers and point the air where you need it. Some higher-end models, like the LG LS090HXV, provide an automatic control that moves the louvers vertically and horizontally as needed.

Washable/removable air filter: This is an important item to make note of if you’re sensitive to allergens. If you know that you will be changing out the filter often or using the unit exclusively in your personal room, you should consider a washable permanent or removable air filter. Save money by not having to buy new filters every few months.

Automatic restart: If the ductless air conditioner experiences a power outage, some models will boot themselves back up and continue running at the previous settings once the power is restored. This is important for locations where air temperature is critical, such as a server room or animal kennel. Be sure to note how long the unit can “remember” the settings and that it will turn back on no matter how long the power is out.

Conclusion

There’s a lot to consider when purchasing a ductless mini split air conditioning system. In our applications with making your garage comfortable, a simple cooling-only model with about 9,000 BTU will get the job done. From there, you can determine all the extras you may need.

Yes, it does seem to have a pretty high up-front price tag, but depending on the model you choose and how often you plan to use it, some air conditioners can end up paying for themselves after only a few years.