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What is a Ductless Mini-Split System?

A sunny afternoon in Hawaii may not always be ideal. The sweltering heat can bring discomfort, stress, or, worse, health risks. 

Installing an air conditioner in your Kauai, Oahu, or Kona home is the solution for comfort and improved indoor air quality.

But before you make an AC purchase, you should first identify your needs and preferences. It is essential to ask:

A mini split system
  • How big is the space that needs air conditioning? 
  • What is the right cooling capacity? 
  • What functions do you require from an AC unit?
  • How much is your budget? 

By answering these questions, you can narrow down your choices in finding the air conditioning unit fit for your home. 

Types of Heating, Ventilation, and Air Conditioning (HVAC) Systems 

The most common HVAC types are window, central, and mini-split systems. 

A window-type AC is the simplest HVAC type that you can mount on a wall or a window. The condenser faces outward to dispel the heat while the evaporator side faces the room to cool the space.  

Although less expensive compared to other AC types, window-type air conditioners also have the least cooling capacity. You need to install one window-type AC for every room that needs air conditioning. 

Window-type ACs are also hard to move or remove, and their bulky design can be obtrusive in a room.

A central HVAC system cools the entire house by generating cold air at a central area and distributing it through large ducts. 

Installing a central AC system can cost more than $3,000 because of the expensive ductwork installation. 

With a central air system, expect higher energy consumption and bills since you cool the entire home.

A ductless mini-split system is an AC type that falls in between the window-type and central HVAC in terms of price and features.  

How Does a Ductless Mini-Split System Work? 

Like central HVAC, a ductless mini-split system has an indoor air-handling unit and an outdoor condenser. It also has a conduit to link the indoor and outdoor units.  


The evaporator takes warm air from the room, absorbs the moisture and heat, and blows cold air back.

This indoor unit sits on the room wall and measures around 3-feet long.


The ductless condenser receives the heat from inside your home and disperses it into the outside. The condenser is the outdoor unit. 


The ductless AC unit sends the moisture and heat it has collected through the conduit. The conduit is a cable that houses the condensate drain, refrigerant tubing, power, and communication cable. 

The main difference between a central and ductless HVAC is its cold air delivery system. 

Central ACs distribute cold air through an air duct network while mini-split ACs directly blow cold air to the space it cools.   

With ductless mini-split systems, you can control the temperature in individual spaces or rooms. 

This AC type is ideal for houses or additional rooms without spaces for ductwork. Energy-efficient homes and multi-family housing that require small space air conditioning can also benefit from ductless mini-split systems.  

Benefits of a Ductless Mini-Split System

With a ductless mini-split system, you can experience comfort, improved air quality, and these other benefits:        

Zoning Capability

You can regulate the temperature of every area or room. Depending on the model, you can connect up to four indoor air handling units to one outdoor condenser. 

Each indoor unit has a thermostat to control the room temperature. You can turn off the unit in rooms that you do not use. You can also adjust the temperature in areas that require more cooling.  

Zoning is ideal for compartmentalized spaces. When you add an extension to your house, like an apartment for young couples or elders, you can easily adjust each room’s temperature with individual indoor units.

Energy and Cost Savings

Mini-split systems have a high seasonal energy efficiency ratio (SEER), an industry-standard measuring AC efficiency. The ratios range from 18 to 30 SEER, higher compared to central and window-type ACs. The higher the SEER, the lower the energy bills. 

You do not lose energy and money due to duct leaks, since the ductless split-type system produces and distributes cold air where it is located. 

Zoning and the use of fans with variable speed also equate to energy efficiency and cost savings.  

Flexible Installation

Conduit lengths can reach more than 50 feet. You can hide the compressor at the back of the house even when the air handler is on the front side.   

Most indoor units have sleek designs and jackets made from high-quality materials. 

Because indoor air handlers do not rely on ductwork, you can hang them on a wall, flush them into a drop ceiling, or suspend them from a ceiling.

The outdoor and indoor unit hook-up only requires a three-inch wall hole for the conduit, unlike window-type or wall-mounted ACs that provide an easy opening for intruders.  

Low Noise

Sound ratings for ductless mini-split systems indoor units can register 19 decibels, quiet as a whisper. You can also place the condenser far from the living spaces to minimize the noise.

Ductless Mini-Split System Installation

Most ductless mini-split systems require professional installation. Only an HVAC technician can charge refrigerant lines with R410A.

Improper HVAC installation can increase room humidity, inconsistent temperatures, and refrigerant or carbon monoxide leaks.

Your HVAC professionals will survey your home and identify ideal locations to mount the outdoor and indoor units.

They may also recommend a dual or multi-zone system depending on the number of areas that require air conditioning.

Ductless Mini-Split System Maintenance

Regular maintenance of your ductless mini-split type system extends your unit’s life and ensures its optimum performance. Here are simple maintenance tasks:

  • Clean and change air filters regularly.
  • Keep dirt and debris away from the outside unit.
  • Clean the condenser coils with a dry cloth.
  • Check for mold and mildew.
  • Check for condensation and ice buildup.
  • Schedule regular cleaning, inspection, and tune-up services from an HVAC professional.  

Island Comfort Air Conditioning Services

Our HVAC technicians will be glad to install a ductless mini-split system in your Hawaii home.

They will perform checks and maintenance to your unit to prevent issues that can lead to unit breakdown and costly emergency repairs.

For fast and reliable ductless mini-split system installation, repair, and maintenance services in Kauai, Oahu, and Kona, call Island Comfort at (888) 781-0364 and schedule an appointment today.