AT A CROSSROADS ROADS

With the right push, air conditioners can shift from energy guzzlers to climate allies in India’s energy efficiency story

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ONCE CONSIDERED a luxury, room air conditioners (ACs) have become an essential for home comfort amid rising temperatures and rapid urbanisation. Estimates indicate that India’s AC market is expanding swiftly. In 2021-22, over 8.4 million units were sold; by 2023-24, this number had increased to 10.9 million, according to “India Energy Scenario 202324” report by the Bureau of Energy Efficiency (bee). Alliance for an Energy Efficient Economy (aeee), a Delhi-based non-profit, estimates that nearly one in 10 Indian households now owns an AC—a figure comparable to car ownership. This number is expected to quadruple by 2037-38. And this is just the beginning. The key question, then, is how these energy guzzling yet essential cooling devices can be made more energy-efficient, so that household electricity bills can be lower and reduce overall power demand, ultimately saving the government valuable resources.

The effort to regulate the energy efficiency of ACs began in the 2000s. In 2009, bee mandated star-rating for ACs using Energy Efficiency Ratio (eer). The methodology required calculating the ratio of an AC unit’s cooling output (in watts) to its total power input (in watts), under fixed conditions: an outdoor temperature of 35°C, an indoor temperature of 27°C, and 50 per cent relative humidity. However, this approach was flawed, as it did not account for seasonal variations in outdoor temperatures, which influence cooling demand and, consequently, energy consumption. For instance, an AC works harder and consumes more energy to cool a room when the outdoor temperature is 40oC, compared to 35oC. To address this issue, bee in 2015 introduced a new star-rating methodology: the Indian Seasonal Energy Efficiency Ratio (iseer). This approach considers varying temperature conditions and operating hours throughout the year, providing a more accurate estimate of energy efficiency. iseer was made mandatory in 2018.