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Energy Star Ratings



Air conditioners provide a space conditioning (cooling only or heating and cooling) service to improve the thermal comfort of an indoor space (such as a room, entire home or larger complex).

Air conditioners are also used in commercial and industrial buildings such as offices, shopping centres and manufacturing premises.

Residential air conditioners (also referred to as heat pumps particularly in New Zealand), were first required to carry an energy label in 1987 and have been subject to Minimum Energy Performance Standards (MEPS) since 2004.

Larger three phase air conditioners (that are normally used in non-residential situations) have been regulated for MEPS since 2001 and have a voluntary labelling scheme.



Types Of Air Conditioners

There are two main types of air conditioning products on the market:

  1. refrigerative products (using the vapour compression cycle)
  2. evaporative products.

Refrigerative products have been the main focus of the E3 Program (and are the focus of this page), however some research has been undertaken on evaporative products and they may be considered in the future.
Refrigerative air conditioners can supply a cooling only service, and reverse cycle products are capable of heating as well as cooling. The main types of products are as follows:

  • Split system (non-ducted): The most common type of household air conditioners. These products have an outdoor unit that houses the compressor and condenser, and an indoor unit that is commonly mounted on a wall. They can range in size to suit a small bedroom, to much larger products that could suit large open plan living areas.
  • Window/wall units: These products contain all parts in a single unit (rather than having a separate outdoor and indoor unit). They are installed either through windows or can be mounted into walls (where the back of the unit will be outdoors). They are typically less efficient, but cheaper to purchase and install than split systems and are suitable for cooling or heating single rooms.
  • Ducted systems: Ducted products can provide heating and cooling for an entire home or premises, delivering warm/cool air via ducts positioned in various rooms. These systems can be zoned so that only certain areas are being conditioned (for instance only living areas during the day). Two types of systems are:
    • domestic ducted units are split systems that consist of a single outdoor unit connected to an indoor unit installed in the roof cavity or under the floor
    • commercial ducted units tend to consist of a single unit on the roof or next to a wall and are connected to the building through ductwork only. They are available in single phase and three phase power and energy labelling is voluntary for these products.
  • Multi-split systems: Multi-splits consist of multiple indoor units connected to a single outdoor unit. These can allow for different temperatures in different rooms.
  • Double/triple split system: An increasingly uncommon configuration that consists of a single outdoor unit and two or three indoor units that cannot be controlled individually.




Domestic single phase, non-ducted air conditioners must carry an Energy Rating Label. Labels on ducted systems are voluntary, so not all products will have one. You can still view their energy efficiency performance on the GEMS Registration Database. In manufacturer’s literature they may refer to energy efficiency ratios (EER) and co-efficients of performance (COP) which are the efficiency ratings for cooling and heating respectively. They are simply a ratio of the output (capacity) divided by the power input. They may also mention an annualised version of these metrics (AEER and ACOP). These are virtually the same thing, but deduct standby power. The Energy Rating Comparison Tool provides the power input and outputs for all products, even unlabelled ones. This allows you to calculate the EER and COP yourself. You can then compare these and choose a model with a higher EER/AEER and/or COP/ACOP.

For non-ducted household air conditioners, you can still compare models online or using the free Energy Rating app, but you can also use the label. Air conditioner labels are a little bit different to labels for other household products and have some product specific information on them.


The Stars



Just like on other appliances, air conditioners are given star ratings, blue for their cooling function and red for their heating function (unless the appliance is a cooling only device, and then it will have the blue stars only). The more stars a product has, the more efficient it is. Air conditioners can currently be rated up to 10 stars. If a product is rated at 6 stars or less, it will not show the extra star ‘super efficiency rating’ band. You can see on the above example that this unit is rated 7 stars for cooling and 4 for heating, so only the cooling star arch has the additional coronet.

You can compare the efficiency of different products using the stars, however you must compare products of the same or similar size. You can find this in the middle of the label, in the capacity output box.


Capacity output and power input


The capacity output figures on an air conditioner label will let you know the amount of cooling and heating the model can produce. These are the figures you should check are of similar value when comparing star ratings.

The power input shows you how much power is required to produce the heat or cooling shown in the capacity output box. If two products have the same star rating and same capacity output you can see which product is more efficient by choosing the one with the lower power input.

Some labels may also have a separate declaration within the heating output and input box, as shown above. This number will show the heating output capacity of the product when tested at 2 degrees Celsius. The main figure is based on testing at 7 degrees. When outside temperatures are below approximately 5 degrees, outdoor units can begin to ice up and this will impact on the capacity of the unit (i.e. the amount of space it can heat). This declaration is voluntary and won’t be found on all models. However if you live in an area that regularly has temperatures below 5 degrees, it can be worth looking for this figure or asking your retailer or installer.


Variable output compressor

This box shows whether the unit has a variable output compressor, commonly known as an ‘inverter’ air conditioner. These units are able to vary the speed at which they operate to suit conditions, so on a mild summer day they won’t have to work as hard as when it’s 40 degrees outside. Traditional single speed air conditioners, which are less common today, simply turn on and off as set temperatures are met.

Demand response capability

The Demand Response (AS4755) section of the label refers to the appliances’ inbuilt capability of participating in a voluntary peak electricity demand management program.

  • Mode 1 means the appliance is capable of being turned off and back on.
  • Mode 2 means the appliance is capable of being turned down by 50%.
  • Mode 3 means the appliance is capable of being turned down by 25%.


Zoned Label


Zoned Energy Rating Label

Installed location can have a significant impact on the energy efficiency and performance of certain appliances (mainly space conditioners and water heaters), with contributing factors including air temperature, water temperature, frosting, humidity, cloud cover. For this reason, the Energy Efficiency Advisory Team (EEAT) is examining a move to a zone-based energy efficiency labelling system for some products or product categories.

A Zoned Energy Rating Label (ZERL) will provide enhanced information to consumers and advisors about product energy efficiency and other key performance attributes relevant to their location. It will allow for meaningful comparisons of energy efficiency, running costs and key performance attributes across technologies.


Size Matters: Air Conditioners

When considering purchasing a new air conditioner, the most important initial step is to ensure you select a suitably sized unit. Unlike other products such as televisions, where the size of the product is obvious, air conditioners typically look similar despite having wide ranges of heating and/or cooling capacities. Sizing for air conditioners is provided as a kilowatt (kW) capacity output figure (not to be confused with the power input, which is the amount of power required to produce the listed cooling and/or heating output) and you can find this on the energy rating label, as well as on the manufacturer’s product literature.

There are many different elements within your home that will impact on the size air conditioner you’ll require. These include (but are not limited to):

  • Whether you are looking to heat/cool a single room, a larger space or your entire home;
  • Size of room/home (including ceiling height);
  • External wall materials;
  • Insulation levels; and
  • How many windows you have, their glazing, shading and orientation.

Because of all these factors, it’s best to have a professional advise you on the size air conditioner to look for. There are also free online tools you can use to give yourself a rough idea.

Another element to consider is where you live. If you live in a cool climate, or where in winter temperatures are regularly below 5 degrees Celsius, it’s important that the unit you choose is able to cope in these conditions. Some models’ capacity will reduce at these times so you may find it unable to heat your space sufficiently, while others are able to continue to meet or exceed their capacity. Some manufacturers will test their products at a colder temperature and provide the capacity output for 2 degrees Celsius. This information isn’t always easy to find though, so check with your retailer or installer to see if they can assist.

Undersized units will have to work harder to heat or cool your room, and may be unable to reach and maintain your preferred temperature. Oversized products will typically be less energy efficient and they’re likely to cost more upfront as well.

Ensuring the product you have selected is an appropriate size will mean you’ll remain comfortable in your home and not use more energy than necessary.


Extra Information: