How Do Ductless Air Conditioner Systems Work?

Whether you’re seeking a more energy-efficient cooling solution or grappling with cooling a house that doesn’t accommodate ducted systems, ductless air conditioners, also known as mini-splits, could be your answer.

But how do these systems work? And are they right for your situation? In this guide, we’ll answer these questions and more.

3 Components of a Ductless (Mini-Split) HVAC System

The typical mini-split system consists of three main components:

Outdoor Condenser: This unit houses the compressor, which circulates the refrigerant that absorbs and dispels heat.

Indoor Air Handlers: These units are installed in the rooms you want to cool. They contain an evaporator coil and fan to distribute cooled air.

Refrigerant Tubing, Power Cable, and Condensate Drain: These elements connect the indoor and outdoor units, circulating refrigerant, providing power, and draining condensation from the indoor unit to the outdoors.

How Does a Ductless Air Conditioner Work?

A ductless AC works by transporting heat energy from inside your home to the outdoors. The indoor unit’s evaporator coil absorbs heat from the room, and the refrigerant in the coil carries that heat to the outdoor unit, where it is expelled.

Meanwhile, the cooled air from the indoor unit is circulated back into the room, thereby reducing the room temperature.

When are Ductless Air Conditioners a Better Option?

Ductless systems are often a better option for homes that lack existing ductwork, in additions to a house, in rooms that don’t cool well, or in homes where installing ductwork would be challenging or impractical.

Because of their energy efficiency, they’re also excellent choices for homeowners seeking to reduce energy consumption and costs.

How to Install a Ductless Air Conditioner?

Installation of a ductless air conditioning system involves mounting the indoor air handlers on an exterior wall, installing the outdoor condenser unit, and connecting the two with refrigerant tubing and a power cable.

Due to the complexity of the task, it’s typically best left to professionals.

Pros of a Ductless Minisplit System

Ductless systems are energy efficient, reducing costs due to their direct cooling capabilities and lack of duct leakage. They offer zone control, allowing you to cool specific rooms without affecting the entire building. Additionally, their compact size and flexibility for zoning or heating and cooling individual rooms make them a popular choice.

Cons of a Ductless Minisplit System

While ductless mini-split systems are highly efficient, they are also more expensive upfront than central air conditioners. Also, they require regular cleaning to maintain optimal performance and avoid mold growth. Furthermore, some people may not prefer the aesthetic of indoor units mounted on their walls.

How Much Does a Ductless Minisplit System Cost?

The cost of a ductless mini-split system varies depending on the model, number of indoor units, and the complexity of the installation. On average, you can expect to pay between $1,500 to $2,000 per ton (12,000 BTU per hour) of cooling capacity.

Do Ductless HVAC Systems Also Heat?

Yes, when equipped with a ductless heat pump, these systems can also provide heat. The heat pump can reverse the process, absorbing heat from the outdoors and moving it indoors to warm the house.

What is a Ductless Heat Pump?

A ductless heat pump is a type of HVAC system that both cools and heats your home. It works like a regular heat pump, but without the ductwork, it directly transfers heat to or from your living space.

How Long do Ductless HVAC Systems Last?

With proper maintenance, ductless systems can last up to 20 years, potentially longer than traditional central air conditioning systems.

How Many Rooms can a Ductless Minisplit Cover?

A single-zone mini-split can cool one room, while multi-split systems can cover multiple rooms. The specific number of rooms depends on the system’s capacity and the square footage of the rooms.

Do Ductless Air Conditioners Need a Vent?

No, ductless air conditioners do not require a vent. They use a small conduit for the refrigerant line, power cable, and condensate drain, but no large vents are needed.

How Well Do Ductless Air Conditioners Work?

Ductless air conditioners work exceptionally well, offering energy efficiency, flexible placement, and excellent zone control. They are particularly effective in specific applications where traditional ducted systems may not be ideal.

How do MiniSplits Work in Cold Weather?

Ductless systems with a heat pump can continue to extract heat from the outdoor air, even in cold temperatures. However, their efficiency can drop as the temperature goes down, and supplemental heating may be necessary in extremely cold climates.


A ductless air conditioner, or mini-split, offers a versatile and energy-efficient solution for cooling andheating your home. It can be a perfect choice for homes without ductwork, smaller spaces, or those seeking zone control.

Despite the higher upfront cost, the long-term benefits such as lower energy bills, longer lifespan, and improved indoor air quality make it an investment worth considering.

Understanding how a ductless system works can help you make the right decision for your home comfort needs. Always consult with a HVAC professional to get the right system for your specific needs and to ensure proper installation.

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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