The new star rating methodology called Indian Seasonal Energy Efficiency Ratio (ISEER) will address the different climatic zones in India and higher temperature.
ISEER measures energy efficiency of air conditioners based on a weighted average of the performance at outside temperatures between 24ºC and 43ºC based on Indian weather data.
Weather profiles of 54 major cities in India shows that 65% of the total number of hours in a year have a temperature above 24ºC (5778 hours out of 8760). Air conditioners in India have until now been tested under the Indian standard IS 1391 at a standard operating conditions of outside temperature of 35ºC.
Talking about ISEER, Shri Sanjay Seth, secretary, bureau of energy efficiency said that the new methodology for rating system will bring in higher energy efficiency of appliances and reduce energy consumption.
Ratings based on ISEER have been introduced on a voluntary basis for inverter air conditioners since June 2015 and proposed to be merged with fixed speed air conditioners in the mandatory regime from January 2018. Some of the leading manufacturers have already adopted the rating for inverter air conditioners.
India has been progressively improving the efficiency of room air conditioners since 2008; a Star-5 air conditioner in 2010 became Star-3 in 2015 and will become Star-1 in 2018 as per new ISEER methodology. The weighted average Energy Efficiency Ratio (EER) of AC has increased from 2.6 in 2006 to 3.26 in 2015, which is an increase of 25% in efficiency due to tightening of standards.
From January 2016, Star-2 will be the least efficient unit that can be sold.