You’ve probably seen the star-filled labels on a number of white goods including air conditioners and wondered how they actually work. They may look confusing, however luckily for us, the Australian Government has already done all the hard work in terms of calculating how energy efficient certain appliances are.

Introduced in 1987, the energy star rating system for residential air conditioners ensures air conditioning manufacturers are subject to a range of Minimum Energy Performance Standards (MEPS) which were introduced in 2004. These specify the minimal level of energy performance that certain products must meet or exceed in order to be offered for sale, and MEPS are mandatory across a range of products in both Australia and New Zealand.

The ratings help make the process of working out the efficiency of air conditioners much easier, and can go a long way towards cost savings on your electricity bills. So they’re vital! Here is a simplified guide to air conditioner star ratings.

Energy Rating Labels

In both Australia and New Zealand, an energy rating label is a label that’s required to be affixed to various appliances prior to retail sale, which includes domestic single phase and also non-ducted air conditioners that are for household use. For non-ducted household air conditioners that don’t have a label, you can still compare models online or by downloading a free Energy Rating app.

The label essentially allows consumers to compare the energy efficiency of a product and helps them work out its capacity, which is how much power a particular model needs to run.

Energy Star Ratings

Air conditioner star ratings are a standard measure of both the cooling and heating efficiency of an air conditioning unit, which, in industry terms, represents the Energy Efficient Ratio (EER) in terms of cooling and the Co-efficient Of Performance (COP) in terms of heating. In order to work these out, the ratio of the energy output (or capacity) of a unit is divided by the power input.

Air conditioners have their own specific star rating labels, which are slightly different from labels found on other electrical products. Cooling-only systems have a set of blue stars, while those that both heat and cool (like reverse cycle systems) have a set of red stars as well which represent their heating capacity. Products are rated according to the number of stars on the label – the more stars it has, the more efficient it is.

Air conditioners can currently be rated up to 10 stars, however if a product is rated with six stars or less, it won’t show the extra star ‘super efficiency rating’ band on the label.

These energy rating labels offer prospective buyers a simple way to compare similar systems, however it’s important to remember that you must compare products of the same or similar size. You can do this by checking the capacity outbox box that you’ll find in the middle of the label.

Capacity Output and Power Input

Choosing the right sized air conditioner for your needs is vital, however you also need to be able to compare similar products in order to make an informed choice. Capacity output figures on air conditioner energy rating labels basically show you the amount of cooling and heating a certain model can produce.

The label will also list a ‘power input’ which will tell you how much power is required to produce the cooling or heating that’s shown in the capacity output box. If you are comparing two products with the same star rating and the same capacity output, choose the one with the lower power input as it will be the most efficient. Simple!

Some energy rating labels will also list a separate declaration within the heating input and output box, which will indicates the heating output capacity of the item when it’s tested at 2°C. This is useful in colder climates where the temperature regularly drops below 5°C, because outdoor units can ‘ice up’ which will impact the units capacity in terms of the amount of space it can heat. This declaration is voluntary however, so if you do live in a chilly area and it’s not listed on the label, check with your retailer or installer.

A Variable Output Compressor tick box also features on some labels, which will tell you whether the system is an inverter model. Inverter systems can vary their speed of operation to suit certain conditions.

No-label Models

Not all air conditioning systems are required to carry energy star rating labels. As mentioned above, they are mandatory on single phase, non-ducted systems, however not on some ducted systems, evaporative air conditioners, multi-split systems, three-phase systems or those intended for purely commercial applications.

No label? No problem! You can easily calculate an air conditioning system’s energy efficiency by downloading the free Energy Rating app, or by calculating the cooling (EER) and heating (COP) efficiency using the government’s Energy Rating Calculator.

Size Considerations

If you’re in the market for a new air conditioner, the most important first step is to make sure you’re selecting a suitably sized unit. Unlike other products like TV’s where the size of the item is pretty obvious, air conditioners can look similar, however their ability to heat and/or cool can be very different. Air conditioning system sizes are generally provided as a kilowatt (kW) capacity output figure. This can be found on the air conditioner star ratings label and/or in the manufacturer’s booklet.

A range of different elements within your home can also impact on the size of the air conditioner you’ll need, which include (but aren’t limited to):

• Whether you are looking to heat and/or cool a single room or your entire home
• The size of the room and your home (including the ceiling height)
• What the external walls are made from
• Your home’s insulation levels
• How many windows you have and their shading, glazing and orientation
• Where you live and the type of weather conditions you experience

Basically, if you buy an undersized unit, it will have to work harder in order to cool and/or heat a room, and may not be able to maintain your preferred temperature. If you buy an oversized unit, it will probably cost more and use far more energy than is necessary. Size does matter!

Need some help choosing the right sized unit for your home? Contact Crown Power today on 0427 175 654 (Brisbane & Sunshine Coast) or on 0409 678 803 (Gold Coast).