The Energy Rating of an appliance must be displayed when it is sold, and so it’s easy to see how efficient the appliance is. The Australian government uses an Energy Star Rating system. One star is the least efficient, all the way up to the most efficient rating of 10 stars. Appliances that have to be Star rated include:
- Clothes washers
- Air conditioners
The Energy Rating Label offers consumers two main pieces of information:
- The Energy Star rating is a comparative assessment of efficiency
- The comparative energy consumption gives an estimated amount of energy the appliance will use over a year, based on typical home use.
Energy Stars and Air Conditioning
You should never buy an air conditioning unit that doesn’t have an Energy Star label. The Minimum Energy Performance Standards (MEPS) program is required by Australian law, and stipulates that air conditioning units must reach a certain standard to be sold and provided to consumers.
The most energy efficient air conditioners are recognised by the award of a TESAW, a government sponsored award that replaced the Galaxy Award system and is presented every year.
Measuring Air Conditioning Performance
An energy efficient air conditioner’s efficiency depends on a number of qualities, including age, standard of maintenance, and internal components, as well as the type of system it is. There are two main measurements of energy efficiency used to show how efficient an air conditioning unit is:
1) Energy Efficiency Ratio (EER)
The EER is how the cooling performance of an appliance is measured, and is typically shown in kilowatts. The cooling capacity is how much heat can be removed from a room, and the heating capacity how much can be added.
2) Coefficient of Performance (COP)
Heating provided by an air conditioning unit is extremely efficient compared to other heating methods, because the amount of power used is lower for comparative heating capacity. The COP is a measurement of a unit’s energy efficiency when heating a room.
Don’t forget the gas
Air conditioners use refrigerant gases to cool air. It’s this gas that was the cause of so much concern when the global warming arguments were at their strongest. The most common used refrigerant gas was R22, and is still used in Australia today. However a new gas, R410a, has a higher thermal volumetric cooling capacity than R22, and produces better thermal exchange properties. If that sounds a little technical, then simply remember this: R410a gives better energy efficiency and is greener than most other refrigerant gases.
A Final word about Energy Stars
The Energy Star rating of an energy efficient air conditioner combines all of the above factors to give a ‘one sight’ visual comparative measure. The more Energy Stars an appliance has, the more efficient it will be: and that means cheaper energy bills and a cleaner and greener planet for all.