The Advantages of a Ductless Mini-Split Air Conditioner System

Sep 9, 2010
Kelly Smith

Energy Star appliances for federal tax credits - US gov

You might have heard about both ductless air conditioners and mini-split A/C units and wondered what the difference is. The answer is, nothing!

There's no doubt that most homes, especially in the southern US, benefit from central air conditioners with their very large evaporator coils and condensers and long runs of ductwork. But even these homes can benefit from a ductless model. Before going into the why, let's take a look at how they work.

How does a Ductless Air Conditioner Work?

As I mentioned above, there are two common names for these units, and they are both concisely descriptive. There are no ducts, they are comparatively smaller than a central unit (think mini), and the two components are split apart.

One component, the evaporator, is mounted to the wall inside the home, usually near the ceiling or on the floor. This part contains a blower to push the cooled air into the room. It's usually controlled with a remote control. The exterior unit is the compressor. The two components are connected with tubes to remove condensate (moisture or humidity) from the room and circulate refrigerant. That's it!

Advantages of Mini-Split Air Conditioners

There are a number of benefits. In many cases when a home addition is made during a remodeling project or when converting a garage into a home office, the central air conditioner and furnace just aren't capable of cooling the new space. It just makes solid financial sense to add a mini unit to take up the slack.

You might ask, “Why not just install a window unit?” For one thing, it's recommended that window units be removed during the winter. That's just inconvenient. For another thing, ductless systems are more energy efficient. For example, the Mitsubishi website says, “We have 15 new Energy Star rated systems with dramatic increases all the way up to 26 SEER. And we have nine new systems that qualify for a federal tax credit of up to $1500.”

Still another benefit is that window units may compromise home security. When nobody is at home it's no great feat to remove the unit and climb into the home to steal the family jewels. To add insult to injury, chances are that they'll make off with the A/C as well!

These units are quiet. Some Mitsubishi ductless systems are as quiet as 19 decibels, which is lower than the typical human whisper. Another benefit is that they are much easier to install than central air conditioner units. No wrestling an evaporator and furnace up into the attic, no running flex or rigid metal ducts, and no cutting into drywall ceilings to install defusers or vents. That really takes the bite out of labor costs.