How to Choose the Right Air Conditioner for Your Home

Choosing the right air conditioner is one of the more significant appliance decisions an Australian household makes. Get it right and you will have reliable, energy-efficient comfort for a decade or more. Get it wrong and you will spend years either sweating through summer because the unit is too small, or watching your electricity bill climb because it is working too hard. This guide covers the main types of air conditioners available in Australia, the key specifications to understand, how to size a unit correctly for your space, and what to look for when comparing models.

Types of Air Conditioners Available in Australia

Split System Air Conditioners

Split systems are the most popular residential air conditioning choice in Australia. They consist of two units: an indoor head unit mounted on an interior wall, and an outdoor compressor unit installed outside the building. The two connect via refrigerant piping and electrical cabling, which means professional installation by a licensed refrigeration technician and electrician is required.

Reverse cycle split systems can both cool and heat, making them a year-round climate control solution. They work by transferring heat rather than generating it, which makes them significantly more energy-efficient than electric resistance heaters. In heating mode, a modern reverse cycle split system typically delivers three to five kilowatts of heat energy for every one kilowatt of electricity consumed, giving a coefficient of performance (COP) well above that of any conventional heater.

Browse our range of split system air conditioners from Westinghouse and Hisense, available in capacities to suit bedrooms, living rooms, and open-plan spaces.

Window and Wall Air Conditioners

Window and wall units are self-contained: the entire refrigeration system sits within a single chassis that mounts through a wall opening or window frame. They are generally less expensive to purchase and install than split systems, and some models can be installed without a licensed refrigeration technician if the unit does not require cutting refrigerant lines.

Wall units are a practical choice for rental properties, older homes where split system installation is difficult, or spaces where a permanent through-wall installation is acceptable. Cooling-only models are available for warmer climates, while reverse cycle variants provide both heating and cooling. Wall units tend to be slightly noisier than split systems because the compressor is closer to the living space.

Understanding Capacity: How to Size an Air Conditioner

Selecting the correct capacity is the single most important decision when buying an air conditioner. Capacity is measured in kilowatts (kW) and refers to the amount of heat the unit can add to or remove from a space per hour. An undersized unit will run continuously without reaching the target temperature; an oversized unit will short-cycle, switching on and off frequently, which reduces efficiency and increases wear on the compressor.

As a general guide for Australian homes with average insulation and ceiling heights of approximately 2.4 metres, allow roughly 0.125 kW of cooling capacity per square metre of floor area in a temperate climate. This means a 20 square metre bedroom typically requires around 2.5 kW, a 30 square metre living room around 3.5 to 4.0 kW, and an open-plan kitchen and living area of 60 square metres around 6.0 to 8.0 kW. These figures increase for north-facing rooms, rooms with large west-facing windows, poorly insulated spaces, or homes in hotter climates such as Queensland or Western Australia.

Always consult the installation guide or a qualified technician for accurate sizing. Undersizing and oversizing are both costly mistakes that no amount of setting adjustment can fully correct.

Energy Efficiency and the Australian Energy Rating Label

All air conditioners sold in Australia are required to carry the Energy Rating Label, administered under the Greenhouse and Energy Minimum Standards (GEMS) Act 2012. The label shows a star rating from one to six for both cooling and heating performance, with more stars indicating greater efficiency. A higher-rated unit costs more upfront but typically delivers meaningful savings on running costs over its lifespan.

Efficiency is also expressed as an Energy Efficiency Ratio (EER) for cooling and a Coefficient of Performance (COP) for heating. A reverse cycle split system with a COP of 4.0 delivers four kilowatts of heat for every one kilowatt of electricity consumed. By comparison, a standard electric bar heater has a COP of 1.0. Over a Queensland winter or a Canberra heating season, this difference becomes very significant in dollar terms.

Inverter Technology

Most modern air conditioners use inverter-controlled compressors. Rather than switching the compressor fully on or off, an inverter unit continuously adjusts the compressor speed to match the cooling or heating load. This results in more stable room temperatures, quieter operation, and considerably better energy efficiency compared to older fixed-speed units. When comparing models, inverter technology is almost always worth the additional cost.

Key Features to Consider

Wi-Fi connectivity allows the unit to be controlled via a smartphone app, which is particularly useful for pre-cooling a home before you arrive. Sleep modes reduce noise and gradually adjust the temperature overnight to prevent the room from becoming too cold. Timer functions let you schedule operation around your routine to minimise running costs. Many units also include auto-restart after a power outage, which is useful in areas prone to outages during severe weather.

Noise levels matter most in bedrooms. The indoor unit noise level in cooling mode is typically expressed in decibels (dB). Units rated below 26 dB are considered quiet for bedroom use; anything above 35 dB will likely be noticeable during sleep. Check the specification sheet rather than relying solely on marketing language.

Australian Climate Considerations

Australia's climate varies dramatically from the tropical north to the cool-temperate south. In tropical and subtropical regions, cooling capacity and humidity control are the primary concerns; heating performance matters less. In southern states and elevated inland areas, a high-COP reverse cycle unit provides genuinely cost-effective winter heating. Coastal properties in humid areas should look for units with good dehumidification performance. All outdoor units must be rated for outdoor installation and should ideally be positioned to avoid direct afternoon sun to maintain efficiency.

Under Australian Consumer Law, air conditioners must be fit for purpose and of acceptable quality. Manufacturers are typically required to support spare parts availability for a reasonable period after the model is discontinued. Keep your installation documentation, warranty card, and proof of purchase in a safe place.

Frequently Asked Questions

What size air conditioner do I need for a bedroom?

For a standard Australian bedroom of 15 to 20 square metres with average insulation, a unit with a cooling capacity of 2.0 to 2.5 kW is generally appropriate. Larger bedrooms, rooms with poor insulation, or those with significant west-facing glass may require 3.0 to 3.5 kW. Always account for your local climate: a 2.5 kW unit suitable for a Melbourne bedroom may be insufficient for the same size room in Brisbane.

Do I need a reverse cycle air conditioner or a cooling-only model?

In most parts of Australia, a reverse cycle (heating and cooling) unit is the better choice. It provides year-round climate control and, in heating mode, is considerably more energy-efficient than electric resistance heaters. Cooling-only models are generally only appropriate in tropical northern regions where heating is rarely needed.

Can I install an air conditioner myself?

In Australia, the refrigerant handling required for split system installation must be carried out by a licensed refrigeration and air conditioning technician. The electrical connection must also be performed by a licensed electrician. Window and wall units that use a sealed pre-charged refrigerant system and a standard power outlet may allow DIY installation in some states, but always check local regulations and the product installation guide before proceeding.

How much does it cost to run an air conditioner?

Running costs depend on the unit's efficiency, the size of the space, local electricity tariffs, and how frequently the unit operates. As a rough guide, a 3.5 kW reverse cycle split system with a COP of 3.5 running for two hours per day costs approximately $0.50 to $0.80 per day at typical Australian electricity rates, though actual costs vary by state and retailer. Choosing a higher Energy Rating star-rated model and using timer and sleep functions can significantly reduce running costs over the unit's lifetime.

What maintenance does an air conditioner need?

The filters in the indoor unit should be cleaned every two to four weeks during periods of regular use. Blocked filters reduce airflow, make the unit work harder, and increase running costs. The outdoor unit should be kept clear of debris, leaves, and overgrown vegetation. Annual servicing by a licensed technician helps maintain performance and extends the unit's operating life.

Ready to Find the Right Air Conditioner?

Explore the full range of air conditioners at Everyday Home Living, including reverse cycle split systems and window and wall units. For complete year-round comfort, also browse our heating and cooling range, which includes electric heaters and air purifiers to complement your air conditioning system.