Air conditioners have come a long way in recent years in terms of energy efficiency. Making your home more energy efficient can also save you money long-term and increase resale value.
When choosing a new system, be sure to check its Energy Star Label: the more stars, the cheaper the running costs. If you have rooftop solar panels, you can even run the air conditioner during the day using power generated from your roof, without running up your power bills.
Just keep your air conditioner serviced and maintained so it can continue to perform efficiently for many years to come.
Air conditioner size
It’s important to get the right size air conditioner for your space. Buy too small a system and it won’t do its job properly; too big and you’ll be wasting money by using excess energy.
When calculating what size you need, there four main things to consider:
- Room size - The larger your room's floor space and ceiling height, the more power you'll need to cool the area.
- Insulation - Poorly insulated rooms will need more power to keep things cool.
- Location - The hotter the climate, the more air conditioning power you’ll need.
- Orientation and windows - A room with large north- or west-facing windows gets hotter and will therefore require a more powerful system than a room with shaded, southern- or east-facing windows.
What is reverse cycle?
Most modern air conditioners are reverse cycle, meaning that they can both heat and cool.
Split system air conditioners
A split system air conditioner is one of the most energy efficient cooling options for your home. They are called 'split system' because they have separate indoor and outdoor units connected by refrigeration piping. This keeps most of the air conditioner's noise outside.
Split system air con works by pumping hot air inside your home to the external refrigeration unit, returning the chilled air inside. In winter, a reverse cycle split system air conditioner returns warm air instead by compressing the refrigerant in a condenser.
Modern split systems can be relatively inexpensive to run if the thermostat is set between 25-27°C degrees in summer, or 18-20°C in winter. Every degree higher or lower in these seasons could add ten per cent to your running costs.
- Unit cost: Each split system unit costs around $600 to $3,000 depending on its energy rating and power (kW).
- Installation cost: Split system air con installation costs a further $600-800 on average.
- Running costs: Running costs depends on the unit's energy rating and your room size. Canstar Blue estimates that a Melbourne household will annually spend $46.01 on cooling and $262.79 on heating a medium-sized room (20-40 metres squared) with a 3-5kW split system air conditioner. Of course, if you have rooftop solar, you could power your air conditioner during the day without running up your energy bill.
- Best suited for: Cooling one or two rooms, such as a bedroom and a living room.
Ducted air conditioners
Ducted air conditioning units are more expensive than split system units, but they can cool your entire house rather than just a room or two at a time.
Ducted systems work by sending the air to a central heating and cooling unit, then sending the chilled or heated air back into your rooms via a series of air ducts and vents.
Many ducted systems now come with smart features, allowing you to turn your system on or off in certain rooms and adjust the temperature using your smartphone.
- Unit cost: A ducted air conditioning system costs between $4,000 and $10,000 on average.
- Installation cost: Ducted air con installation can be quite expensive, climbing to $6,000 or more.
- Running costs: Canstar Blue estimates that a Melbourne household annually spends $326 on cooling and $1,175 on heating using ducted air conditioning.
- Best suited for: Larger homes where you want to cool several rooms at once.