What is a mini split AC and how does it work?

Miniature size, maximum effect

In the kind of heat most of the U.S. is experiencing this summer, it’s imperative for your health and comfort to stay cool. If you aren’t careful, though, staying cool could send your energy bill skyrocketing. To avoid this, you need to use your cooling systems properly and in conjunction with one another. Among the better options for cooling systems are mini split air conditioners. These can be added to one or all of your rooms to target the areas you most want to be cooled.

Shop this article: Senville Leto Series Mini Split Air Conditioner, hOmeLabs Split Type Inverter Air Conditioner and MrCool Ductless Mini Split AC System

What is a mini split AC?

In essence, it’s a smaller, more targeted version of central air that doesn’t require ducts. Both central air and mini split ACs have both interior and exterior components, hence the “split” moniker. Unlike central air, which works on your entire home at once, a mini split AC targets specific rooms or square footage areas around it. The stronger the unit, the more of your home it can cool.

How does a mini split AC work?

To simplify, the exterior portion (called a compressor) pulls hot air and moisture out of your home, while the interior portion injects air cooled by the machine.

Key mini split AC details

Before grabbing a mini split AC, compare your needs to these four aspects.

• Coverage: Mini split AC coverage comes in both zones and square footage. Zones are the number of rooms in which one AC can have an interior unit installed. Most ACs offer one to six zones. However, your AC must have the power to cover the square footage of said rooms.
• Power: Mini split ACs list power in terms of British thermal units. The higher the number, the more square footage a unit can cool effectively. For example, a 450- to 550-square-foot room needs a mini split AC with roughly 10,000 to 12,000 BTU. Most units list the square footage they can cover so you don’t have to do any math.
• Compressor type: Mini split ACs use either rotary or inverter compressors. Rotary compressors are cheaper but use more energy versus expensive but more energy-conscious inverter compressors. If your main AC is a mini split and you use it year-round, invest in an inverter. If your mini split AC just helps out, and only for a few months out of the year, a rotary should be fine.
• Voltage: Most U.S. power outlets use 110 or 120 volts, which most mini split ACs use. However, the most powerful mini split ACs need a 220- or 240-volt outlet. If your home doesn’t already have that, an electrician must upgrade an outlet.

Main mini split AC benefits

Mini split ACs take more effort and money to get going than say, a fan, but they come with several substantial benefits.

• Energy use: Mini split ACs use much less energy than central air for two reasons. The first is that they only cool the locations you specify. The second is that each zone can be set to its own temperature. This means you could keep unused rooms at a high standby temperature, and members of your household can each have their personal temperature comfort level set. Conversely, central air (by definition) cools every area of the home to the same setting, no matter what.
• Air quality: Dust and other particles can accumulate and spread through ducts used by central air. Mini split ACs have no ducts and also use filters for extra cleanliness.
• Noise: Mini split ACs are exceptionally quiet compared to most other cooling methods.
• Aesthetics: It's true that a central air unit is out of sight, out of mind. Similarly, mini split ACs are both insubstantial and can be installed in many configurations to suit your desires. This is lower-profile when compared to window units and fans, which naturally draw the eye.

Best mini split AC units

Senville Leto Series Mini Split Air Conditioner

This unit comes in several strengths so you can get the coverage you need. It has plenty of extra features such as Alexa and Wi-Fi connectivity, plus the ability to heat and dehumidify.

Sold by Amazon

hOmeLabs Split Type Inverter Air Conditioner

This unit requires a 230-volt outlet but comes at a great price for each of its four strength options. It can be set to automatically adjust its temperature based on a built-in thermostat.

Sold by Amazon

MrCool Ductless Mini Split AC System

This beast of a unit has a staggering 36,000 BTU that’s meant to cool a single 1,500-square-foot room. It can cool a similarly sized home with an open floor plan with the help of some fans to move the air around.

Sold by Amazon

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Jordan C Woika writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.