Ductless Air Conditioners

If you're thinking about having a mini-split or ductless air conditioner installed in a room in your home, here is some information you need to have before you go ahead and get out your credit card.

This category section of the website covers this particular type of cooling device and explains what it is, how it works, its pros and cons and other pertinent information that may be useful to a prospective owner.

mini-split air conditionerThis overview article heads up this category and provides the visitor with useful information they can take forward when considering making a purchase.

So to get things underway, let's first look at what this kind of appliance actually is.

What is Ductless Air Conditioning?

This is a common kind of single room cooling unit that you see in homes and offices that do not have a central HVAC system. It is actually comprised of two units, which are:

  1. An inside wall-mounted unit that provides cool (and heated) air inside the room
  2. An outside wall-mounted unit that expels hot air and moisture out of the room

The two units are connected via a short through-wall vent. Because of the way they work together via a refrigeration and heat exchange process where hot, moist exhaust air needs to be expelled to the outside atmosphere, must be installed on an external wall.

This set up is very compact and avoids the need for any ducting in the building. The only drawback is that the unit is dedicated for one room only and cannot be centrally controlled, although as it caters for most people's cooling and heating needs in a certain room, this is not a problem.

This is a similar advantage that comes with using portable air conditioners in each room. However, mini-split ductless air conditioning is more economical to run, more asthetically pleasing and there is no ugly corrugated plastic vent hose connected to a window to contend with.

While there is a distinct economical advantage to using portable vent-free coolers (swamp coolers), the disadvantage of not working in humid conditions generally favors the use of AC in most areas of the country.

How Does a Mini-Split AC Compare to a Window AC Unit?

There are some advantages that a mini-split unit has over a window mounted unit, with the only real disadvantage is a ductless unit generally costs more to purchase and install. Aside from the cost, the advantages make it a much more attractive in-room temperature control solution.

A fixed wall mounted unit has none of the following disadvantages of a window AC unit, which:

Modern ductless systems have the latest remote thermostatic control that can keep the room at a constant, really comfortable temperature as opposed to blasting air on and off as window units have a habit of doing. They also have variable fan speed control so they are whisper quiet at night when on a low setting.

Why are there Two Units?

The way AC works means there is plenty of cold air for keeping the room cool inside, but it also produces hot air as part of the heat exchange process. The cold air is actually produced by a similar process that keeps the contents of your kitchen refrigerator cold.

Warm room temperature air is passed through a lattice of tiny cold pipes inside the unit, which chill the air that is forced out by the internal fan. Those pipes are chilled by compressing a refrigerant gas, a process which produces a similar amount of hot air that must be vented out of the room.

The external unit (condenser) is there to do that as well as vent excess moisture that would otherwise build up inside the indoor unit. By connecting the two through an external wall, all the hot air and moisture can easily vent to the outside and this is aided by the big fans you can hear running in the external condenser.

If the hot air were not vented to the outside, the air cooling process would actually produce more hot air than cold, resulting in a net temperature increase instead of the decrease that the unit is designed to create. That's why there are two units: to vent that hot air out of the room!

More Information

I'm sure if you have gotten this far down the page your interest is in knowing more about how these AC units work and which are the best models for your particular circumstances.

There are many different makes and models on the market so we've put together a series of product reviews and info articles so you can learn more about them and have better choices at your fingertips.

Below you'll see a list of the current articles that cover this topic: