Ductless Mini-Splits: What Voltage Do They Typically Use?

Mini splits are a popular choice for home heating and cooling. These ductless systems are easy to install and fully electric.

And because mini splits are heat pumps, they don’t have the same electricity consumption that other forms of electric heat do. In fact, they can often lower your utility bills.

But what are their electrical requirements when installing a new unit?

What Voltage Do Ductless Mini-Splits Typically Use?

Ductless mini-splits generally require 220 volts, but some smaller models only require 110 volts.

Mini-splits also need to be installed on a dedicated circuit with a disconnect box to allow the power to be cut off for servicing and repair work. This is necessary for code requirements.

For a reminder of the differences between ductless mini-split heat pumps and ducted central air, why not read our article comparing the two systems?

What Is a Ductless Mini-Split?

Before we get into the voltages that different types of mini-splits use, let’s remind ourselves of the basics.

A ductless mini-split is a type of heat pump that is permanently installed in your home as a means of heating and cooling. A mini-split system is “split” into at least two main parts—an outdoor unit and one or more indoor units, also known as air handlers or simply “heads.”

These distinct components contrast with a packaged heat pump or AC unit, which contains all the system mechanisms (the condenser, compressor, and evaporator) in a single unit.

Essentially, a mini split system is “split” between the indoor and outdoor units.

The mini split’s outdoor unit houses the compressor and one of the coils that serves as a condenser or evaporator, depending on the mode of operation.

The indoor unit contains the other coil, used as the evaporator when the system operates in cooling mode, and the condenser in heating mode.

The two units are connected by refrigerant line sets that convey the refrigerant around the system. Electrical wires facilitate communication between the outdoor and head units and provide power.

These systems have their own integrated smart technology. The outdoor and indoor units are in constant communication to ensure maximum energy efficiency while maintaining a consistent indoor air temperature.

Along with the wiring, the units are connected to each other by copper line sets that allow refrigerant to flow through the coils.

The final part of the mini split is a simple condensate drain from the air handler. This drain typically just goes outside and drains into the ground. In some cases, a condensate pump is used.

Ductless Mini-Splits Need a Dedicated Circuit

Mini-splits must be installed on a dedicated circuit to prevent circuit overloading and repeated circuit breakers tripping.

The National Electrical Code (NEC) sets the benchmark for the safe design, installation, and inspection of electrical work in all 50 states of the US.

The NEC states that all major, fastened-in-place electrical appliances, including ductless mini-split heat pumps, require their own dedicated circuits.

This allocation is necessary to prevent circuit breakers from tripping when attempting to run too many appliances simultaneously.

A dedicated circuit has its own circuit breaker in the electrical box, which helps to prevent circuits from overloading and tripping breakers continually.

Domestic outlets in the US provide 110 volts, the same voltage as some of the smaller ductless mini-split heat pumps.

So, you might think you could put a mini-split that requires this voltage on the same circuit.

However, you are risking problems if you do this. Although small 110V units are tiny in terms of Btu, they contain many components that draw power, which can quickly add up. It is also against the code.

The key metric you need to consider for your wiring is the Minimum Circuit Ampacity (MCA). The MCA is the maximum current that a wire can carry continuously without exceeding its temperature rating.

Start-up amperage is high when your mini-split first kicks in when it is likely to draw a much larger current than under standard operation.

If someone is using a hairdryer on the same circuit when this happens, you might have a breaker trip.

Obviously, the more appliances you have on the same circuit, the more likely these complications will be. So always put a mini-split on its own dedicated circuit.

Should I Choose a 110V or 220V Mini-Split?

Depending on the system size you need, you might not have a choice.

Larger mini-split systems (12,000 Btu or above) require 220V to operate. These systems need more power to fulfill their heating and cooling outputs.

On the other hand, smaller mini-split systems that provide heating and cooling for a single zone (say, 12,000 Btu or less) can come in 110-volt or 220-volt versions.

If you go with the 220V model, you will need to draw fewer amps, which means you can use a smaller wire in the installation. This benefit will save you some money, mainly if you run the wire over a long distance.

The majority of mini splits will require 220V. Even if you get a small 110V system, you will still need to install it on its own dedicated circuit with a disconnect box outside.

The difference between these units in regards to power usage is minimal. What’s more important is that you choose the correct size of mini split for the areas it needs to service.

If you’re interested in saving money on your electric bills, you would be much better off following the advice in our article that covers 15 reasons your electricity bill is so high.

Summary

If you’re not experienced with electricity, don’t try to do this yourself. Most HVAC companies are fully capable of installing their own electrical equipment on your main panel and completing the installation up to code.

If you are debating between a 220V and a 110V mini split, don’t get hung up on the voltage.

Choose a system that is sized correctly for your home space. Mini splits have been created to be extremely energy efficient and they will do that regardless of their voltage.