Air Conditioner Buying Guide

1. Size/ Power

When buying Air Conditioners, the first aspect to consider is the power. The power is measured in kilowatts (kW). The power needed to cool or heat a room can vary on several things. For example; the size of a room, the height of a room, if the room has insulation or west facing windows. 

You need to take some care when looking at the power as an Air Conditioner that is too small wont cool or heat your room while one that is to large will use more power unnecessarily.

When considering the required power, you need to look into the size and aspects of the room you are cooling. As a general rule of thumb you can use the below measures:
Bedroom (small rooms) – 100 Watt / square meter
Living Room (large rooms) – 140 Watt / square meter

An Example:
Size = 50m2
Room = Living Room
Power = 50 x 140 = 7.0 kW
However, you can take this even further to look into aspects such as does your room have west facing windows or insulation?

If there is West Facing Windows – Multiply above by 1.2 (add on 20%)
If there is Insulation – Multiply above by 0.9 (deduct 10%)


An Example:
Size = 50m2
Room = Living Room
West Facing Windows = Yes
Insulation = Yes
Power = 50 x 140 x 1.2 x 0.9 = 7.56 kW

These calculations are not perfect as in reality each room varies in shape, size, style and aspects. Therefore, the above should be used more as a guideline rather than a hard and fast rule. However, these calculations and assumptions are a great way to get a reasonable estimate of the power and size required.

2. Type

There are several different types of Air Conditioners on the market. So please take a good look at each one to get a better understanding of what will suit your requirements best.

a) Portable Air Conditioners

Are small, light and portable, meaning it can be placed in any room and move whenever needed. Portable units often have lower power than fixed units. They are often suitable for smaller spaces such as bedrooms or small apartments. These units often require hot air to be directed out of a window.

b) Split System Air Conditioners

Split systems are the most common unit seen. The cooling unit is installed outside with the heated unit and fan mounted inside your home. These systems can get powerful and are typically suited for cooling larger rooms. Some Split Systems will even allow for separate units for different rooms and hence can offer great flexibility.


c) Window Wall Air Conditioners

Window/wall air conditioners are designed to cool/heat the room they are installed in. They are an all in one unit; both the cooling unit and fan are in the one box. They are often less powerful than split systems.

3. Features

Just like every product these days’ air conditioners come with many different features. Some features to be on the lookout for are;

a) Reverse Cycle

An air conditioner that can both heat and cool are known as reverse cycle air conditioners. These air conditioners can internally reverse its operation to provide heating or cooling, as required.

b) Inverter System

Air Conditioners with inverters have the ability to change the temperature of the air they produce, rather than just starting and stopping the motor. These types are often quitter, cheaper to run (more energy efficient) and tend to perform better overall.

c) Air purifier

Units with air purifiers use a filter system to clear and filter the air from things like dust, dust mites, smoke or bacteria. These will create a cleaner environment in the space they operate. This feature is in particular very use for users that suffer from asthma or allergies.

d) Remote Control and Access

A simple one to understand, look out for models with remote controls as some units still won’t offer them.

e) Humidity Control

Some air conditioners will have features to allow you to control the humidity in the air. In other words you can regulate the amount of moisture in the air. People that live in humid areas or have respiratory issues may find this extremely useful.

f) Timers
Timers are a simple feature that go a long way. With timers you can set your air conditioner to start before you get home to a cool or toaster house. It will also allow you to set the timer to turn off the air conditioner for example 1 hour after you go to sleep. Simple, yet useful.

g) Smart Air Conditioner

Some air conditioners will have access via wi-fi and allow control them with model phones and other compatible apps. With smart devices virtually taking over, this may be a feature to look out for.

4. Energy Efficiency

Energy efficiency in air conditioners are often rated in stars. The higher the star rating the more energy efficient that unit is. Units that provide both heating and cooling functions will have a rating for both heating and cooling. Typically air conditioners with inverters are more energy efficient as they have the ability to change temperature without starting and stopping. Typically, larger air conditioners have lower energy start rating then smaller ones.

5. Installation

Please keep in mind that installing air conditioners requires a licenced professional. You cannot install these yourself unless you have the required Victorian licences.
Some other aspects to consider when installing.
  • Mount the head unit high. In general, hot high rises leaving cooler air to stay underneath. Therefore, mounting the unit up high means that when cooling the colder air will tend to sink to the bottom of the room giving better cooling.
  • Try to mount the outside unit in an area that does not get direct sunlight. Direct sunlight can lead to the unit being slightly less efficient.