scorecardresearch
Monday, September 15, 2025
Support Our Journalism
HomeScienceWhy India's magic number for AC temp is 24°C? Science, compromise &...

Why India’s magic number for AC temp is 24°C? Science, compromise & Net Zero mission

The demand for ACs is growing exponentially. In 2024, a record 14 million AC units were sold in India. By 2030, this figure will more than double.

Follow Us :
Text Size:

New Delhi: Each summer, as India’s peak electricity demand rises, much of the attention turns to a single appliance: the air conditioner. With cooling contributing around 25-30 per cent of the country’s peak energy load, the AC ends up taking much of the blame. In June this year, Union power minister Manohar Lal Khattar proposed guidelines to limit the temperature range for ACs across the country — 20 to 28°C.

This proposal to hardwire a temperature range for new ACs builds upon an earlier mandate by the Bureau of Energy Efficiency (BEE), a statutory body under the Ministry of Power. In 2020, the BEE mandated a default thermostat setting for star-rated air conditioners: 24°C. Now, the ‘magic number’ is back in conversation with a renewed push to discourage consumers from going below this.

The goal, as always, is to save energy, cut emissions, and ease stress on India’s power grid. It also ties directly to the India Cooling Action Plan (ICAP), which seeks to reduce overall cooling demand by 20-25 per cent by 2037-2038. 

If humidity complicates the science, consumer behaviour does so even more. Many users set the temperature in their ACs far lower than necessary, noted B Thiagarajan, Managing Director of Blue Star. It’s often because installers leave them at 18-19°C after testing, or because people assume the colder the setting, the faster the cooling will be.

“Strictly speaking, the human body even at 26°C should feel comfortable,” Thiagarajan said. “It’s actually the combination of humidity and temperature that matters and not just the temperature alone. But in many places — cinemas, hotels, restaurants and buses — ACs are run unnecessarily at very low temperatures, making people uncomfortable enough to use jackets or blankets indoors.”

Cooling and climate

Ultimately, it’s all about climate change. And everyone, whether consumers, manufacturers or policymakers, will have to act responsibly to reduce emissions as part of the Net Zero mission, Thiagarajan said. In this context, every effort toward cutting emissions assumes significance. That’s why air conditioners are at the heart of this debate, despite only about 8-10 per cent of Indian households owning them. 

But demand for ACs is growing exponentially. In 2024, a record 14 million AC units were sold in India. By 2030, this figure will more than double, Thiagarajan said.

“Our projections show that India is the fastest-growing AC market in the world, and by 2050, we will most probably become the largest market,” he added.

This will further push the share of cooling needs in India’s peak energy demand of 240-250 GW. While estimates vary, AEEE’s Kumar puts it around 25-30 per cent (60-75 GW), which could reach close to 100 GW by 2030, driven by rising AC sales and higher urban temperatures from the urban heat island (UHI) effect and climate change.

Given this, researchers are now focused on finding alternative paths to reduce the use of AC itself. One of the ways, Malaviya said, could include better building design — from cross-ventilation to reflective roof coatings and cooling paints. 

The emissions link is also direct: India’s grid emits about 727 grams of CO₂ for every kilowatt-hour of electricity generated. 

“Whatever energy you save, you can directly link that to carbon dioxide emissions,” Kumar explained. He emphasised moving toward renewables like solar or wind for electricity generation, after reducing cooling demand through measures such as passive building design and the adoption of energy-efficient air-conditioning technology. 

The government, meanwhile, is yet to determine exactly how much energy and emissions have been saved since 2020, or how much it expects to save going forward, through the 24°C policy. As per a 2018 estimate by the BEE, setting ACs at 24°C instead of 20°C could save about 20 billion units (kWh) of electricity annually, translating to 16-18 million tonnes of CO₂ if widely adopted.

ThePrint reached out to officials in the BEE with a list of questions for updated figures but has yet to receive a response.

For Rawal, however, the bigger challenge is not just what temperature people set, but how they access and use cooling in daily life.

“Access to cooling is a must for health and productivity, but consumption has to be responsible,” he said. “You don’t have to be a slave to the AC 24/7 throughout the year. During favourable outdoor conditions in the mornings and evenings, we must open windows. The rest of the time, windows can remain shut and airtight. The solutions are always somewhere in the middle, not at the extremes.”

While it remains a challenge to satisfy the cooling needs of a diverse populace, policymakers seem determined to bring Indians on the same page: cool doesn’t have to mean cold.

Note: This article is part of a learning programme organised by the Danida Fellowship Centre (DFC) in Denmark in collaboration with the Royal Danish Embassy in Brazil. ThePrint is participating in the programme ‘Reporting from the Frontline of the Global Climate Crisis in an Era of Fake News’.

(Edited by Ratan Priya)

Subscribe to our channels on YouTube, Telegram & WhatsApp

Support Our Journalism

India needs fair, non-hyphenated and questioning journalism, packed with on-ground reporting. ThePrint – with exceptional reporters, columnists and editors – is doing just that.

Sustaining this needs support from wonderful readers like you.

Whether you live in India or overseas, you can take a paid subscription by clicking here.

Support Our Journalism

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Most Popular