Australian testing methods used to create energy ratings for air conditioners are flawed, according to new research released by engineering firm Vipac.
The company has urged regulators to revise test standards so that ratings better represent a unit's field performance across all modes of operation. Variable speed compressor (inverter) air conditioners are the most commonly used in Australia, accounting for 80 per cent of market share.
Vipac's senior project engineer, Dr Satya Mavuri, said Australia's current regulations allow these manufacturers to lock the compressor speed at a fixed setting when testing inverters.
"This produces biased energy ratings since it only reflects an air conditioner's performance in this setting," he said.
"Our research shows that when units are locked, most inverters produce capacities at lower power inputs and therefore appear more energy efficient than they would in unlocked modes. However, unlocked modes are more representative of a unit's real life operation."
All air conditioners sold in Australia must comply with Minimum Energy Performance Standards (MEPS) and the star-based Energy Rating Label (ERL) scheme.
Dr Mavuri said manufacturers increase their chances of inverters passing MEPS and gaining more ERL stars by running tests at locked settings.
"Most of the inverters we tested under unlocked settings were unstable and less efficient than their rated values, thereby warranting less stars than currently assigned to them," he said.
"This means consumers may be unknowingly buying air conditioners with lower energy efficiency than indicated on the label.
"When energy efficiency labelling plays a crucial role in a purchasing decision, it is the industry's responsibility to give consumers accurate information to make their choice."
Australia's energy labelling requirements are specified under the Greenhouse and Energy Minimum Standards Act (GEMS) which is administered by the federal Department of Industry, Innovation and Science.
Commenting on the research, a department spokesperson told CCN that air conditioner test standards are based on international standards such as ISO 5151.
"These same rating methods are used by every developed region in the world," she said.
However, the spokesperson did admit that some energy efficiency issues have been identified for some air conditioners.
"International test methods have not necessarily kept pace with different air conditioning technologies and the way these technologies may operate in particular conditions," she said.
Steps are being taken to address this, she said, with the Airconditioner and Commercial Refrigeration Advisory Committee (ACRAC) working with industry, manufacturers and test labs to identify possible changes to testing for the ISO standard.
"The Equipment Energy Efficiency (E3) program will continue to influence and build international consensus on the need to develop new international testing methods for inverter air conditioners," she said.
Although Standards Australia does not undertake testing or certification, it does oversee the development process with standards drafted by technical committees.
Airconditioners sold in Australia comply with AS/NZS 3823.2.
Standards Australia public affairs officer, Torrin Marquardt, said the organisation has not received any proposals to review this standard.
Asked if Vipac had contacted the organisation, Marquardt said that while no formal representations had been made "we encourage stakeholders to submit a proposal" if there are any issues or concerns.
