High AC Usage in Chennai Fuels Climate Emissions, Poor Maintenance Worsens Impact

Air conditioners (ACs), an appliance increasingly seen as essential in the face of rising temperatures, are themselves becoming a major contributor to the climate crisis.

The AC usage in Chennai is the most intense among the cities surveyed by the International Forum for Environment, Sustainability Technology (iFOREST). The survey, taking into account 3,100 households across seven major cities, i.e., Delhi, Mumbai, Kolkata, Ahmedabad, Pune and Jaipur highlighted a rapid rise in AC ownership, a sub-optimal service sector, high refrigerant refilling rates that increase both household expenses and greenhouse gas emissions and significant gaps in policy implementation.

The report also mentioned that the Indian households use AC for an average of 4.4 hours a day as the city faces long, humid summers, which nearly 87% of households owning just one AC while 13% of households owning more than two ACs. However, awareness about the impact of refrigerants on climate remains low. Around 64% of respondents in Chennai admitted they are unaware of climate-friendly refrigerant options, and only 16% showed willingness to switch to greener alternatives if they were affordable, which is the lowest among all surveyed cities.

According to the study, more than half of all residential air conditioners in Chennai receive refrigerant top-ups annually, making it the city with the highest rate of refrigerant refilling out of the seven.  This number is significantly higher than the 41% national average. A properly operating air conditioner should ideally only require refilling once every five years, but in India, this is more common than it should be, frequently without addressing the leak that initially caused the gas loss.

The study further noted that this practice has both financial and environmental costs. Each refill costs households in Chennai an average of ₹2,300, the highest in the country, and contributes to the release of powerful greenhouse gases.

Many a times, refrigerants escape into the air when leaks are not repaired and the gas is refilled, it causes global warming as these refrigerants have hundreds of times more warming potential than CO2. This happens due to the presence of most commonly used refrigerant, HFC-32, which has a global warming potential that is 675 times higher than carbon dioxide.

Looking at the bigger picture, the iFOREST study estimated that refrigerant leakage alone contributed to 52 million tonnes of CO₂-equivalent emissions in 2024, with emissions from refrigerant release expected to rise to 84 million tonnes of CO2e by 2035.

Neglected ACs Harm Climate

A 2025 ScienceDirect study by the Indian Institute of Technology (IIT) Delhi found that improper maintenance of air conditioners, including frequent refrigerant refills without addressing the underlying leaks, increases instances of carbon emissions.

The above mentioned study also advocated for strict enforcement of refrigerant management protocols and technician training to mitigate environmental impacts.