Ductless air conditioning is ideal for cooling a home or a room not equipped with the traditional HVAC ductwork. This type of A/C is also called mini split due to its size and the fact that -- unlike bulky, noisy window units -- it's split into two parts: an outdoor compressor (the noisy part) and a number of indoor evaporators or "air handlers." You need only a small hole in the exterior wall to install a mini split A/C system, making it fast and easy to set up. Even better, ductless air conditioning, being extremely energy efficient, can keep your whole family comfortable in even the warmest weather while, at the same time, saving money on your electricity bills.

Find out more about energy-saving ductless A/C.

Does Not Lose Energy

Mini-split A/C can save you energy. When you shop for air conditioning, you may find ductless and ducted systems that are rated similarly for energy efficiency. However, in practice, the central system will tend to lose a great deal of energy -- as much as 30 percent -- via the ductwork. HVAC ductwork can lose energy in two ways:

1. leakage of cooled (or heated, in winter) air due to improper sealing
   
   
2. conduction as the result of insufficient insulation, especially if the system extends through an unconditioned (read "hot"!) attic.

Can Be Zoned

Another energy-efficient aspect of ductless air conditioning is that it is simple to zone. Each air handler has its own individually controlled, programmable thermostat, making it easy to fine-tune the temperature of every room to the users' personal preference and habits. What's more, it is necessary to cool only the rooms which are occupied at any given time. There is no need to waste expensive A/C on empty living space.

Easy Installation

Ductless A/C installation is ideal for a situation where retrofitting or extending your ductwork would not be possible, making it practical for spaces such as small condos, income properties, enclosed patios, garages converted to living space, or additions to your home. It is also advisable for a landmark home or an area with low ceilings, since ductwork installation takes up at least a foot of ceiling height and will distort the profile of your rooms.

Cost to Install Ductless A/C

The initial cost of the units is relatively high, $1500-2000 per ton of cooling capacity, or about double that of a window unit, and one-third more than a central system. However, in the latter case, you need to add on the price of the ductwork (basic cost is about $7-9 per linear foot), as well as the disruption caused by the construction, electrical installation, inspection, etc., etc. By contrast, the cost to install mini-split A/C is approximately $1000 in total and can be completed quickly. 

Drawbacks of Ductless Air Conditioning

Whether mounted high on the wall or near the floor, or recessed into a dropped ceiling, mini-split A/C is usually more noticeable than the vent of a central ducted system, although it's less unsightly than a window air conditioner. The air handler generally resembles a baseboard heater in size and shape, which many people find unattractive. However, manufacturers are beginning to come up with some interesting ways to hide the evaporator so that it will blend in to your decor, such as behind a specially built picture frame.

In addition, you will need to find a qualified HVAC contractor who is experienced in working with ductless air conditioners for both installation and repairs.

Laura Firszt writes for networx.com.

Updated August 27, 2018.