The Ultimate Guide to Buying Air Conditioning: Part 2

Choosing the Best Air Conditioner For You

If you’re struggling to choose an air conditioner for your home, you’re not alone. Most people understand that choosing a system that suits their home and lifestyle will be more cost effective, but what they often don’t know is how to evaluate which is best. This is the second of a four part series to help you buy your perfect air conditioner. The first part explained the main attributes of each types of air conditioner. This second section looks at choosing an air conditioner to meet your needs and your home’s design and location.

Meeting Your Needs

This table will help you determine the type of air conditioner that will best suit you.

Purchase Considerations for the Main Types of Air Conditioner

	Evaporative	Ducted Reverse Cycle	Split System	Multi -Head Split System
Installed purchase price	$3,000 – $7,000	$6,000 – $25,000	$1,500 – $5,000	$5,000 – $20,000
Heating and cooling	Cooling only	Both	Both	Both
Whole of home	Yes	Yes	One room only	Room only. Up to 9 rooms run by one outdoor unit.
Performs well in humidity?	No. Best suited to a temperate climate. Performance drops as humidity increases	Yes in cool and temperate climates. Doesn’t suit the highly humid tropical climate	Yes	Yes
Comfort maintained when above 36^oC?	No	Yes	Yes	Yes
Running costs	Very low	Highest because whole home, reduced by zoning	High	High
System size	Up to 11 outlets	6-25kW	2-9kW	5-15kW
Area treats	Up to 240sqm	40-165sqm*	18-65sqm*	35-105sqm*
Typical system life	10 – 15 yrs	10 – 20 yrs	5 – 15 yrs**	12 – 20 yrs

*Based on 145 watts per square meter. If your home is thermally efficient you may have a lower wattage.

** There is a wide variation in quality of split systems and hence variation in system life.

Your Budget

The price of the air conditioner depends on:

The size of air conditioner (cooling power).
Quality and brand of air conditioner.
Features provided and optional extras.
Complexity of installation.
The components and air conditioning controller used, their quality and features (ducted systems).

Wall split systems typically cost from $1,500 installed for a 2.5kW system with a back to back installation. This is enough to cool/heat a standard bedroom.

Floor, cassette and bulk head split systems are more expensive than wall split system air conditioners. They are usually installed when there is no wall space to install a wall split system.

Whilst ducted reverse cycle air conditioning is the ultimate way to heat and cool your whole home it is a more expensive option to buy. As a rule of thumb if you’re going to air condition at least three or four rooms it is generally more affordable, better for your power loading and more aesthetically pleasing to choose a ducted reverse cycle air conditioner than multiple wall split systems.

Multi head systems are not popular because they are expensive to buy and install compared to equivalent wall splits or ducted reverse cycle air conditioning.

For people who want to cool their whole home but can’t afford, or don’t want the high running costs of a ducted reverse cycle air conditioner, (ducted) evaporative air conditioning is a great choice. If you also want to heat your whole home, people normally buy a separate ducted gas heating system which has its own system of ducting and outlets. Buying both a ducted evaporative air conditioner and a ducted gas heating system costs a bit more than buying a ducted reverse cycle air conditioning system. The combined running cost of these systems is lower than running a ducted reverse cycle system for the same length of time.

The Best Air Conditioner for Australia’s Climate

Australia is vast and has various climates. All types of room split systems are suitable across Australia. In heating mode, split systems direct airflow downwards to maximise the heating benefit.

Evaporative and ducted reverse cycle air conditioning are not effective in tropical Northern Australia because of high humidity. Evaporative air conditioners perform best in the dry climate of Southern Australia, mid and Southern Western Australia and Victoria. An evaporative air conditioner can only reduce the temperature by a maximum of 12°C and the breeze it generates provides another perceived 2-4°C cooling effect. Individuals have different temperatures in which they are comfortable (between 22°C and 26°C). As a rule of thumb, individuals will start to notice the limitations of evaporative air conditioning on a humid day when the outside temperature exceeds 36°C.

Running Costs

Refrigerated Air Conditioners

All air conditioners except evaporative air conditioners use refrigerant to heat or cool the air – the technology is similar to how your fridge works. This is an efficient form of heating and cooling, with approximately 3kW of heating or cooling generated for every kW of electricity consumed. The bigger the air conditioner (in kW) the more electricity the air conditioner consumes. Air conditioners run for many hours, so you will find annual running costs are quite significant.

Ducted reverse cycle air conditioners are usually zoned – split into different areas to reduce the area being air conditioned at any one time. This reduces the running cost.

Evaporative Air Conditioners

Evaporative air conditioners use electricity to operate the fan and the water management system – for this reason they are very cheap to run. The water that evaporative air conditioners use has to be dumped every few hours to stop calcium and other mineral salts building up on the pads.

Space to Install the Air Conditioner

To install a wall split system you need suitable wall space on or close to an exterior wall where the outdoor unit is to be located. If there isn’t a suitable space you may need to install a condensation pump or install an alternative type of room only split system, which costs more to buy.
Most homes have sufficient roof space to install evaporative or ducted reverse cycle air conditioning. A ducted system cannot fit into a home with a flat roof or with a very low roof pitch. In a two storey home, you need penetrations to allow ducting to reach the ground floor. For safety of installation and servicing, it may not be possible to install an evaporative air conditioner on a roof with a very steep pitch.

Continue reading Part 3 of our guide to help select a quality appliance that suits your needs.