'Your 5 star AC may actually be worse than 1 star AC'

If you think your '5-star' air conditioner is helping you save on monthly electricity charges, it is time you find other ways to save your power bills. According to a study by Centre for Science and Environment your so-called '5-star' rated split AC becomes worse than a 2 or 1-star rated AC as soon as the temperature soars over 40 degree celsius.

According to Bureau of Energy Efficiency (BEE), a 5-star AC is supposed to save 20-22 per cent of your energy cost compared to a 1-star AC. But the CSE study shows in peak summers, when temperatures are around 40 to 50 degree range, a 5-star AC can start consuming 10-28 per cent more power than its declared capacity.

"We wanted to find out how AC units perform under different outdoor temperature conditions and how that affects the energy savings from the star labeling programme of the Bureau of Energy Efficiency (BEE)," says Anumita Roychowdhury, executive director-research and advocacy, Centre for Science and Environment (CSE), while releasing the Centre's latest study on air conditioners.

In Delhi, air conditioning accounts for about 28 per cent of the total monthly electricity consumption during the hottest months. According to the BEE, ACs are responsible for almost 60 per cent of the Delhi's peak electricity demand.

Cooling capacity of room ACs also drops by about 30 per cent in peak summers, which means a 1.5-tonne AC acts like a 1-tonne AC, the report said.

CSE released the results of its lab tests of energy performance of popular 5-star rated split room air conditioners (RACs) under normal and maximum temperature conditions. The tests were carried out in a National Accreditation Board for Testing and Calibration Laboratory (NABL)-accredited laboratory based in Delhi.

BEE should make it mandatory for manufacturers to declare the tests results carried out based on multiple higher temperature range and declare the results on their product labels. The star labelling system should be adapted to this system, the report said.