The Electrical & Mechanical Services Department will investigate allegations that some air conditioners' cooling capacity and energy consumption deviates from the registered data under Energy Efficiency Labelling Scheme.

The department has asked relevant suppliers to re-test the concerned air conditioners. If it finds any non-compliance under the scheme, it will take action, including de-registering any offending appliance from the scheme.

The Consumer Council today said it commissioned an independent laboratory to carry out performance tests on 15 models of window-type air conditioners.

Of the 15 models, four had cooling capacity and energy consumption measurements that deviated from the registered data under the scheme.

The department has been carrying out random inspections and commissions labs to carry out performance tests on selected appliances to ensure the  registered data's accuracy.

In the past two years, the number of annual compliance tests for air conditioners has increased from four to 10 models.