Mini Split vs. Central Air: 5 Things to Consider

Here are the top five things to consider when choosing the best home climate control solution for your needs.

According to the Energy Information Administration (EIA), approximately 87% of all households in the United States have an air conditioning system. About 60% of these households are equipped with central air conditioning and 23% use individual AC units, such as mini splits.

If you are unfamiliar with the difference between central AC and mini splits, here is a brief explanation of how each type functions.

Central AC is a conventional way to heat and cool your home and has been installed in American households since 1914. A central air conditioner uses an outdoor unit to capture outside air and circulate it through your home via a network of ducts and vents. If you see wall- or ceiling-mounted vents in select rooms of a particular house, it means it has ducting for a central air conditioning system.

There are two types of central ACs: packaged and split-system (which should not be confused with mini splits). A packaged central AC combines the compressor, condenser, blower, and evaporator into a single, large outdoor unit.

A split-system central AC uses a smaller outdoor unit containing a condenser and compressor and an indoor unit housing the evaporator and the blower. You typically find an indoor unit in the basement or attic, connected to the house’s ducting network.

Mitsubishi Electric invented mini split AC systems in the 1950s, introducing the Mr. Slim product line to the market. Although the name may seem similar to split-system central ACs at first glance, the two are different.

Although both mini splits and central ACs use an outdoor unit to capture and cycle outdoor air into the house, they use different delivery methods. Mini splits do not rely on ducts to deliver cooled air. Instead, they use refrigerant lines and one or multiple indoor wall- or ceiling-mounted units, each containing a blower, an air filter, and an array of cooling coils.

The electrical and refrigerant lines used by mini split ACs are much smaller in diameter than the typical central AC duct, requiring small diameter tubing—often no more than a few inches wide. This feature allows housing without a duct network to benefit from an air conditioning system.

When choosing a home air conditioning system, each type has its pros and cons. Here are the five most important factors to consider when choosing one over the other for your house.

The cost is critical for most homeowners when choosing a new air conditioning system. The average cost of a central air conditioner varies between $2,500 and $7,500 (depending on size and capacity), whereas the average price of a ductless mini split system varies between $1,000 and $5,000.

However, it is crucial to understand the sticker price and installation costs are not the only aspects to consider. If your house doesn’t have existing ducting for central AC, or if your existing ducting requires updating, you may need to pay additional fees. These fees are between $1,900 and $6,000 and cover the cost of new ducts, insulation, vents, and installation.

When purchasing a mini split AC, you pay for a complete system that functions without ducting. The only additional fees involved with mini split systems are professional installation costs, which is a worthwhile investment to ensure proper function and long-lasting durability.

According to a 2018 EIA report, the national average air conditioning costs account for 12% of a household’s energy expenditures. However, the percentage varies significantly depending on the geographic region.

States in hot-humid environments, such as Florida, south Texas, Louisiana, or Georgia, spend as much as 27% of their energy budget on air conditioning. States in cold or very cold climates, such as the northern or mountain states, may spend as little as 5%.

These differences in climate and air conditioning emphasize the importance of choosing a cost-efficient system. In this category, mini splits are a clear winner, based on:

SEER Ratings

Many HVAC appliances possess a Seasonal Energy Efficiency Ratio (SEER) rating. The SEER rating represents your air conditioner’s average year-round cost-efficiency. The SEER rating is the air conditioning equivalent of gas mileage in a motor vehicle. The higher the value, the better the energy efficiency.

For example, a 30,000 BTU (2.5-ton) SEER 13 air conditioner consumes approximately $904 in electricity every year. Upgrading to a SEER 21 system of the same size (e.g., Multi 21 and Series C Gree 30,000 BTU air conditioners) will consume $560 of electricity annually instead, making it about 38% more cost-efficient.

Central vs. Mini Split SEER

Although the SEER rating of a specific model varies depending on its size, capacity, manufacturer, and build quality, modern central ACs tend to have lower SEER ratings than equivalent mini splits.

The average central AC has a SEER rating of 13, and the highest-rated models typically have SEER 25 or 26. Federal law currently requires mini splits to have a minimum rating of SEER 13 in northern states and 14 in southern states.

Additionally, many affordable models with ratings between 20 and 30 are available, and the top-rated mini splits go as high as SEER 35. Gree mini split model ranges such as the Vireo and Sapphire feature SEER ratings of 25 or more.

These requirements will increase by one point starting in 2023 (14 and 15, respectively) to promote further energy efficiency.

If you live in a colder climate, you need an air conditioner system capable of both cooling and heating your house as needed. Although you can find central AC and mini split systems capable of performing both tasks, it is critical to understand how they work and why one may not be as efficient as the other.

Central Heating

The heating equivalent of central air conditioning is called forced-air heating. Like central AC, a forced-air heating system uses ducts to control the temperature inside your house. Instead of using a compressor to pull in cold outdoor air, central heating relies on the furnace, pulling in warm air and cycling cold indoor air out.

The primary advantage of central heating is its power. A properly sized central heating unit can keep your home warm even under freezing temperatures.

However, like central AC, forced-air systems require ducting to function. Additionally, while a forced-air system can use the same ducting as central air conditioning, they are a separate unit from central AC, requiring an additional purchase if you need both.

Another known disadvantage of central heating is the noise they generate, which can be a concern if the unit is near bedrooms or frequently visited parts of the house.

Mini Split Heat Pumps

The mini split heat pump is similar in appearance and function to the standard mini split. The only practical difference is that a mini split heat pump can cool and heat, whereas standard mini splits are cooling-only.

Mini split heat pumps offer the same advantages as standard mini split AC units: They are ductless, energy-efficient, support zoning, and ideal for homes without existing ductwork.

Although most mini split heat pumps are designed to function in mild and cool climates, with an operating range of 5°F to 75°F, households in colder areas can choose cold-weather models capable of efficient heating, even with outside temperatures as low as -13°F.

An example is the Hyper Heat line of Mitsubishi mini split multi-zone systems, which is the extra-heating version of the Mr. Slim model range.

One of the defining characteristics of a mini split air conditioning system is flexibility. A mini split system may be single-zone (one room) or multi-zone (multiple rooms). There are as many indoor units as the system has zones; for instance, a quad-zone system has four indoor units.

Zoning allows you to install temperature control in the parts of the house that need it the most, such as the living room, the bedrooms, the kitchen, the basement, converted garages, and other hard-to-cool parts of the house.

The primary advantage of a zoned mini split system is the added level of control and efficiency over your house’s indoor climate.

Independent Zone Control

When you turn on the central air system, it always runs at 100%, and it will send air to every room with ducting, even if they are currently unused or unoccupied. However, each indoor unit of a multi-zone mini split system can be independently controlled and turned on or off, allowing you to avoid wasting energy in spaces that don’t need it.

For instance, if your house has a 4-zone LG split air conditioner system, turning only two of your four zones means that your air conditioning system consumes only 50% of its theoretical maximum, helping you save more money.

Varying Cooling Needs

A multi-zone mini split is also the only way to precisely adjust the temperature in each room, which is ideal for meeting different cooling needs.

For example, you can set a unit installed in the living room to 72°F while the unit in the primary bedroom is configured to 77°F. A central AC requires you to select a target temperature for the entire house, which may not be comfortable for everyone.

If you purchased or built a new home or are currently remodeling your property, you may be wondering how long it will take to install a new air conditioning system. You’ll also want to know whether it will disrupt daily life inside your home.

Central Air Systems

The installation time of a new central air system varies depending on whether your house already possesses suitable ducting.

If your home is already equipped with ducts and vents of the correct size, a professional team can install a new central air system or replace an old one in two to three days. Most of the work takes place outside with little disturbance.

However, the installation time (and associated costs) double if your property requires installing new ducting or replacing old and inadequate ducts with newer ones. For instance, if your house was built before the 1960s, your ductwork might contain asbestos insulation, requiring technicians to spend additional time and specialized gear to safely remove it.

Mini Split Systems

Installing a mini split system requires considerably less time and work than a new central air system.

On average, a professional team needs a few hours to install the outdoor unit and each indoor unit. The most complex mini split systems (4+ zones) typically require no more than two days of installation time.

Professional installation of a mini split system consists of the following parts:

• Installing the outdoor unit
• Drilling 3" pilot holes for refrigerant and electrical line piping
• Placing mounting brackets on the walls
• Mounting the indoor units in the brackets
• Connecting and testing the system

Even as technicians work indoors to drill pilot holes and install indoor units, an experienced team typically performs this job quickly and with little disturbance. You don’t need to worry about being unable to use the bedroom or the kitchen while work is in progress.

The time needed to install a new mini split system may increase if your house is relatively large or requires navigating around a complex electrical network. However, you should still expect the system to be ready for use within two days.

Whether you live in a small home or a larger property, our comprehensive inventory of single-zone and multi-zone mini splits can keep your indoor atmosphere as cozy and comfortable as you need.

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