What Is a Mini Split Air Conditioner and How Does It Work?

Bry'Ana Arvie
Written by Bry'Ana Arvie
Updated August 17, 2021
Woman on conference call on couch with mini-split on wall
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Mini split air conditioners are the ductless, more energy-efficient versions of traditional central units

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Mini split air conditioners aren’t widely known, but they’re a great alternative to central units (which most homeowners didn’t realize they had options for). With its flexible, money- and energy-saving potential, more people are learning about them and switching over to these systems. 

Read on to see what mini split ACs are, how they work, what makes them different from central units, and if one is right for you.

What Is a Mini Split Air Conditioner?

A mini split air conditioner offers heating and cooling capabilities and works similar to a central air conditioner—but without any ducts. It has two main components, an outdoor compressor and an indoor unit that you’ll use to control the temperature of individual rooms.

How Does a Mini Split System Work?

The indoor unit removes heat from a space by pushing the warm air through evaporator coils. Then the refrigerant absorbs that heat and moves it through the coils until it reaches the outdoor compressor. The outdoor unit has a condenser that releases the air from the coils to the outside. 

And the unit does this for each room with a ductless air conditioner, allowing for separate temperature control for individual spaces.

What’s the Difference Between Mini Split and Central Air?

Mini split and central air conditioning units use the same parts to regulate your home’s temperature. And they’re both super effective at helping you reach the desired temperature for your home. But that’s where the similarities end. 

One of the main differences between them is that mini splits are ductless systems while central units have ducts. Central units move cool air through their ducts to all rooms in your home. During this process, air can leak through your ductwork if you have an old or improperly designed system, which can lead to your AC unit working overtime to cool off your home. This results in a high utility bill and a system that’s not exactly energy-efficient. 

With ductless mini split systems, the air goes directly to your rooms without using more energy than necessary. It’ll also provide cooler air because the cool air moves directly to your room and not through ducts where it’ll get warmer before reaching your space.

What Are the Advantages of Mini Split Air Conditioners?

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Mini splits offer distinct benefits over standard central units.

Shorter Installation Time

Mini splits are primarily assembled in the factory, so it’ll only take a local HVAC pro up to two days to install your system (versus around a week for a central system). They’ll place the indoor air handler unit in your room and drill a single hole in your wall for the conduit, which will house all the lines necessary for your indoor and outdoor units to function together.

Cheaper Utility Bill

Because ductless systems spend less energy getting air from your outdoor unit to your indoor one, they’re much easier on your utility bill. Also, most units use variable fan speeds, which also can reduce your bill. These cool off your room at a high fan speed, then lower it to maintain the desired temperature once it’s reached.

Temperature Flexibility

Everyone in your household may never agree on the perfect temperature. But when you have multiple mini split systems, everyone can control the temperature in their personal space to their preference. 

Also, having air conditioning in specific rooms in your home might be unnecessary, such as in your attic or storage room. So you can choose not to install a mini split system in that space if you want, or install one and only turn it on when needed.

Quieter Cooling

Indoor air-handling units are quieter than central ones. And while the outside unit still generates noise, you don’t need to install it as close to your home as a traditional unit would need.

What Are the Disadvantages of Mini Split Air Conditioners?

These ductless systems aren’t perfect; they do have their share of setbacks that you’ll need to consider if you’re interested in installing them in your home.

Only Suitable for Smaller Homes

Ductless mini split systems don’t have the cooling capacity for homes above 2,500 square feet. If you have a larger home and want to cool your whole space, then mini splits aren’t the best air conditioner size for you, and you’ll need to choose a different system.

Not-So-Great Aesthetics

Because ductless air conditioners need to be placed on either your wall or ceiling, they can clash with your decor. So, if you’re not interested in seeing your air conditioner taking up visible space in your home, this can be a drawback for you.

Expensive Initial Cost

Mini split systems can save you money in the long run, but they’re an investment upfront. They’re approximately 30% more expensive than their traditional counterparts. Installing a ductless mini split system can cost between $2,000 to $14,500, with an average of $4,000 for a 12,000 BTU system.

Is a Mini Split System Worth the Cost?

And as mentioned, the initial cost is pricey, but it does result in a cheaper utility bill over time. Depending on your needs, a mini split might be worth the cost for you if:

  • You’re adding additional space to your home or remodeling it

  • You’re downsizing your home

  • You’re interested in its heating and cooling potential

  • You need to cater to multiple temperature needs

  • You don’t currently have or need ductwork in your home

  • You want to provide cooling in an untraditional room

Ultimately, it depends on your budget and what your cooling priorities are. If you’re not sure what might be best for your circumstances, consider contacting an air conditioner installer near you to get personalized advice.

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