What is ductless air conditioning?

A ductless mini split system, in its most basic form, includes one outdoor unit and one indoor unit, connected by refrigerant tubing and electrical wiring. The indoor unit is often wall-mounted, and delivers heated or cooled air directly into the living space – no duct work needed.

The short answer? Ductless AC (also called “mini-split AC”) work the same way a central air conditioner works—just without the ducts.

You see, ductless AC and central AC produce cool air exactly the same way: they suck in warm air from your home, absorb the heat and moisture from that air, then dump the heat/moisture outside.

The main difference between the 2 systems is how they deliver cool air:

• Ductless AC blow cold air directly into the one room/area it cools (sans ducts)
• Central AC blow cold air into a network of air ducts where it’s dispersed throughout the entire home

Let’s take a deeper look at how ductless air conditioners work and how they cool your home without the use of duct work.

Ductless AC units focus on cooling one room

Ductless AC units do exactly what their name suggests: provide cooling without the need for air ducts. These units don’t need ducts because they only cool one room (versus cooling an entire home like a central AC unit).

Let’s take a closer look at a ductless air conditioner’s setup…

Ductless AC contain 3 main components:

1. A blower/evaporator unit

The blower and evaporator unit is the “indoor unit” that sits on the wall of the room that the unit serves. These units are usually thin and around 3’ long. Their job is to suck in warm air from that room, absorb the heat and moisture from the air, then blow the cold air right back into the room.

As the unit blows cold air into the room, it simultaneously sends all the heat and moisture it’s collected outside via the “conduit”.

2. A conduit

A ductless AC’s “conduit” connects the indoor unit to the outdoor unit. The conduit is basically a thin, long cable that houses the power cable, refrigerant tubing and a condensate drain.

The conduit feeds electrical power to both the indoor and outdoor units. It’s also the pathway where the heat and moisture from inside your home exits and makes its way toward the condenser.

3. A condenser

The ductless condenser is the “outside” unit. Its job is to receive all the heat from inside your home and “dump” it into the outdoor air.

Pros and cons of ductless AC units

Pros:

• Because they cool just one room, ductless units provide built-in “zoning”. Zoning means each room gets its own remote control to cool the rooms to different temperatures.
• With ductless AC, you don’t have to worry about losing money (and cool air) to duct leaks. According to Energy.gov, 20-30% of conditioned air is wasted via duct leakage.
• With a ductless AC system, you can install up to 4 evaporator units to one condenser unit to cool multiple rooms.
• They’re an excellent (and less costly) option for older homes without duct work, when compared to the cost of installing a central AC + duct work.

Cons:

• Ductless AC units have a may have a higher upfront cost than central AC systems IF your home has existing duct work. However, if you have an old home without existing duct work, a ductless mini split is the more cost effective choice since it bypasses the expense of installing duct work throughout your home (a $10,000+ project).
• Unlike central air conditioners, you can’t hide a ductless AC’s indoor unit. Remember that a ductless indoor air handler is attached to the interior wall (as opposed to a central AC’s indoor unit which is typically hidden in an attic/basement/closet). However, ductless AC units are much more sleek and less obtrusive than a window AC unit. So, if your home doesn’t have existing duct work and you’re looking for the better option between a ductless unit and a window AC unit, this probably isn’t too much of a “con”.

Wondering if a ductless AC unit will work for your home?