Air Conditioning – Ducted, or Separate Units?

Guest post by Hubert Dwight

Choosing between split systems and ducted air conditioning systems is no easy task.

We understand that nagging voice in the back of your head that keeps asking “Will we go for a split systems or go for it and purchase a ducted air con system?”

Weighing up the advantages and disadvantages of both air conditioning systems is not easy and often ends up in people going for the builders standard option.

Here is some information on the pros and their cons of the alternatives.

Ducted System

Characteristics of  ducted systems are:ducted heating vent

  • Neater with small vents, typically set in ceiling like the one on the right;
  • Centrally controllable;
  • Can have multiple zones;
  • Only one unit to maintain;
  • Air flows are less obvious in larger rooms due to several outlets;
  • You can direct the system capacity to a restricted number of zones;
  • Adjusting ceiling vents is difficult: you will need a step ladder;
  • To be effective need open doors between outlet vents, and return air inlet.
  • For larger homes you may need to Upgrade to 3 phase power;

It can be worthwhile getting a unit with variable fan speeds. . . . . . instead of ‘Low-Med-High’ other wise you may find the fan being too noisy when you are only using a a single zone.

Separate Units

System characteristics are:
Split system

  • If you only cool key rooms it can be cheaper to install and run (have units in every room running constantly and it will be more expensive);
  • Individual temperature control for each unit;
  • Ceiling space isn’t filled with ducting;
  • Individual temperature control for each unit;
  • Failure less off an issue as doors can be left open to get some cooling effect from ajacent cooled rooms;
  • Can close doors between ‘zones’ without affecting performance;
  • More intrusive appearance, and air flow is more obvious.


Can’t decide perhaps a combination system might suit you?

For instance  have ducted heating and cooling in Kitchen, Meals, Family and Theatre rooms; Split systems in the bedrooms.

Running a split system to heat or cool the bedroom is more energy efficient than running a big ducted unit.

Being able to individually control the temperatures in each bedroom is handy as children won’t want their rooms heated or cooled when you do.

Its useful you can set a split system heater in the bedroom to run for an hour or so at bedroom before shutting off.