We may not know what a perfect life is. In an Indian summer, it may come down to something as simple as sitting at home in relative comfort with people who love each other. However, the climate is not suitable for such a simple human comfort.

Death came in many ways to Bihar. Acute Encephalopathy Syndrome killed over 100, including 79 children, in June, while heat snuffed out 184 lives till June 17. Forty-five people died in 24 hours on June 15. Temperatures around 45C scorched Aurangabad, Gaya, and Nawada in Bihar on June 15 and 16, and stayed above 40C for more than a week. Many places in Bihar clocked 5.1C higher than the normal maximum summer temperature. The monsoon, which was supposed to arrive by June 10, played truant for more than a week, deepening the public misery.

On June 1, Churu in Rajasthan recorded a maximum of 50.8C. On June 10, the thermometer showed 48C in Delhi, breaking the old record of 47.8C on June 9, 2014. In May-June, many parts of the north-western and eastern states, and Vidarbha, Madhya Pradesh, coastal Andhra Pradesh and Telangana saw temperatures stay above 40C for consecutive weeks, in what is likely to be the longest heat wave in the country’s history. This follows the heat wave of 2016, when Phalodi in Rajasthan witnessed 51C, which was, by some records, the third-highest ever recorded anywhere in the world.

Nobody knows how bad it should get before it gets really bad: two-thirds of the country suffers heat waves, half the country is parched, with Maharashtra facing the worst spell in 47 years. Of the last five monsoons three have been deficient; the delayed monsoon this year worsened overall rainfall deficiency to 43 per cent in the first half of June. To say that India’s sixth largest city, Chennai, is suffering from a water crisis is a gross understatement. Four of its major reservoirs are dry.


In an irony for the ages, air pollution and irrigation are masking the extremes of the 2019 heat wave, according to an analysis in Carbon Brief  by researchers from World Weather Attribution (WWA), an international effort to analyse and communicate the possible influence of climate change on extreme weather events. Air pollution, they say, blocks sunlight, thus decreasing maximum temperatures, and irrigation helps evaporate water more and keeps warming down. However, heat waves have become more humid. The health impacts of heat waves are being exacerbated by humidity and air pollution.

A steady drumbeat of studies shows what’s in store. Humid heat waves will hit 30 per cent of people in India, Pakistan and Bangladesh by 2100 if there are no emission reductions, and temperatures will be close to the limits of survivability, according to a 2017 article in Science Advances. Exposure to humid heat may increase by a factor of five to ten, with 150-750 million person-days of exposure above those seen in today’s worst heat waves by 2070-2080, says a 2017 article in Environmental Research Letters. In a 2017 article in the International Journal of Environmental Research and Public Health, authors Gulrez Shah Azhar and others document the heat vulnerability index for 640 districts in India. Of these, 10 and 97 districts fall in the very high and high risk categories, respectively, and are in central India.

“It all boils down to one issue: India's economic injustices have dire consequences for the majority of people. But the heat emergencies that have become an annual tragedy take injustice to the extreme.”

While 90 per cent of Indians pine for cooling solutions beyond their means, 10 per cent use air conditioning to beat the heat, according to the 2018 factsheet from TERI-the Energy and Resources Institute, the Natural Resources Defence Council (NRDC) and the Institute for Governance and Sustainable Development (IGSD).



ising temperatures, urbanisation and incomes drive the demand for cooling around the globe. The factsheet says the use of room AC units in India is rising exponentially. It notes that the stock grew from four million units in 2014 to around 30 million in 2017. AC sales in 2017 alone stood at 5.5 million. By 2030, the report expects the number to be between 55 and 124 million units. While only 10 per cent of India’s population owns ACs, it accounts for the largest share of residential power consumption and the largest source of peak demand in many cities, according to the report. In the business-as-usual scenario, by 2030, India’s AC use is expected to become the world’s largest contributor to new electricity demand, 80-145 gigawatts to the country’s peak power demand. Installed capacity today is 356 gigawatts.

Stan Cox is a senior researcher at the Land Institute in Salina, Kansas, US. The author of Losing Our Cool: Uncomfortable Truths About Our Air-Conditioned World( and Finding New Ways To Get Through the Summer) says, “It all boils down to one issue: India's economic injustices have dire consequences for the majority of people. But the heat emergencies that have become an annual tragedy take injustice to the extreme.”

On writing about a visit to Anantapur in 2007, he said, “‘Trickle-down economics’ never works as advertised. In India, it may mutate into ‘down-to-a-trickle’ economics.” Speaking of economic injustice, he says, “A minority can escape heat stroke and death, and even be comfortable, because they can afford this technology, while the majority are trapped in the deadly heat.

“The need for protection from heat waves is growing but economic injustice is denying that. And that is also alongside wasteful, lavish use.” He thinks it would be a gigantic effort, but the only way to address heat waves in the short run would be to air-condition large spaces supplied with ample water in every neighbourhood or village for people to take refuge.

“I know that's not practical on such a scale, but to the extent it could be attempted, it should.”


“The AC has become an aspirational article for the middle class—the moment you cross a specific income threshold, most people buy one,” says Nikit Abhyankar, a researcher in the International Energy Studies Group at Lawrence Berkeley National Laboratory. He has conducted research and policy analysis on a range of energy issues in the developing country context such as renewable energy, energy efficiency, and power sector reforms and regulation. At present, he leads the International Energy Studies Group’s work on the Indian power sector.

ACs are experiencing the “smartphone moment”. A decade ago, only a handful could afford it. With prices dropping it became a mass product.


According to his analysis, every year  room AC sales grow  by 10-15 per cent. Over the next 15 years, AC use in India would increase 6-7 times. It will add around 100-150GW to the peak demand, about 30 per cent of total peak demand. Ninety per cent of the ACs used in India are room units, while about 10 per cent is central AC. Of the former, about two-thirds is in the residential sector while one-third is in the small commercial and industrial sector. Room ACs account for 10-15 per cent of total electricity consumption in India but it is growing rapidly.

In urban centres like Delhi and Mumbai, this percentage is as high as 30-40 per cent. Abhayankar says  the impact of ACs on peak demand is significant. In Delhi, ACs alone contribute to over 60 per cent of peak electricity demand—the time of the day when electricity use is the highest—in the summer months (July-August). One room AC consumes twice the power of all other typical household appliances combined. 

ACs are experiencing what he calls the “smartphone moment”. A decade ago, only a handful could afford it. However, with prices dropping it became a mass product, he says. It happened in China. In the early-mid 1990s in China, room AC use in urban households was about 2-3 per cent. In 15 years (late-2000s), that use crossed 100 per cent—an addition of more than 200-250 million ACs in 15 years, which added about 200-250GW to the peak load.

Abhyankar says improving efficiency will reduce energy use. Room ACs worldwide including India have become significantly more efficient. For example, he says, between 2006 and 2016 the market average efficiency of room ACs in India improved by over 30 per cent, thanks to Bureau of Energy Efficiency’s (BEE) Standards and the Labelling Program.

ACs sold in India have to get a label from the BEE. A one-star label indicates the lowest efficiency level while five star is the highest—meaning that the 5-star AC consumes about 30 per cent less power than a 1-star AC. Typically, market average for room ACs is around 3-star. Manufacturers use a lot of simple engineering solutions to make ACs efficient. For example, 5-star ACs would have a more efficient compressor that uses inverter technology. It also has a better “heat exchanger”—both responsible for a significant efficiency improvement.

A typical 1-star AC would consume about 3000 kWh of electricity each year, while a typical 5-star AC would consume about 2000 kWh. Assuming a power tariff of Rs 8-10/kWh (most AC users will be in the highest tariff bracket), that’s a saving of over Rs 8,000 a year—which helps recover the incremental price of the 5-star AC in about 2-3 years. 

Some consumers want to purchase better products than 5-star. So, manufacturers are using even more efficient compressors, better heat exchangers, control systems, which make them even more efficient. In several other economies including China, such super-efficient products are becoming a norm. India’s Energy Efficiency Services Limited (EESL) has launched a bulk-procurement programme for installing 100,000 super-efficient ACs about 15 per cent more efficient than 5-star.

Lighting a 100-watt bulb requires burning 325 kg of coal. It releases 840 kg of carbon dioxide, the main cause of global warming. A typical air conditioner uses about 15 times that amount of coal.

There are significant technology options for improving AC efficiency.  For example, five-star inverter ACs are significantly more efficient than the market average. Additionally, several room ACs commercially available in the market have an efficiency that is 25-30 per cent higher than the five-star AC. Although they are more expensive, buyers recover that extra cost through electricity bill savings in less than two years. Globally, the most efficient product is 50 per cent more efficient than India’s five-star.  

“It’s time India revised its labels to match global market trends,” says Abhyankar, “Government policy also has a big role to play.”

Japan, for example, runs a top-runner programme that has been very successful in increasing AC efficiency aggressively.

“Studies have shown ACs can provide certain human health and productivity benefits. There is a need to meet that demand in a sustainable manner. “ACs are energy guzzlers, therefore, increasing demand would imply increasing energy supply significantly, which raises some important equity and environmental justice issues.”

Mostly, coal and oil are used to produce electricity. Lighting a 100-watt bulb requires burning 325 kg of coal. It releases 840 kg of carbon dioxide, the main cause of global warming, and other greenhouse gases (GhGs) like sulphur dioxide, the cause of acid rain, and nitrogen oxides, the cause of acid rain and smog. A typical air conditioner uses about 15 times that amount of coal, says Gulrez Shah Azhar, a doctoral candidate at the Pardee RAND Graduate School and an assistant policy researcher at the RAND Corporation in the US, who previously worked at Public Foundation of India, Ahmedabad, and was the author of the Ahmedabad Heat Action Plan.  

Burning coal to produce electricity is a wasteful and toxic process, with 60 per cent of coal wasted as heat and 40 per cent converted to electricity. In India, it’s a moot point how much coal and oil  the car and industrial air conditioning burns, and how much is used in refrigerators, cold chains, and so on. Hospital cooling is another. According to a Kigali Cooling Efficiency Program report China, the US, and India represent 45 per cent of the total hospital cooling carbon dioxide equivalent emissions. The refrigerants—hydroflurocarbons (HFCs)—used in ACs leak into the atmosphere, and are potent GhGs, which linger for about 14 years and are 1,000 to 3,000 times potentially more powerful than carbon dioxide.

It is possible to solve the global cooling challenge and enable thermal comfort for all without warming the planet: the solution lies in a breakthrough cooling technology with five times less climate impact.

So, air conditioning drives up energy use, which mostly comes from fossil fuels and exacerbates warming by releasing HFCs. It also locks us in a vicious cycle: the more you cool indoors, the hotter it gets outside, which requires more cooling inside.



n the present growth trajectory, the number of room air conditioner (RAC) units worldwide could increase from 1.2 billion today to 4.5 billion by 2050. Home air conditioning alone could raise world temperatures an additional half degree Celsius by 2100, according to a report from the Rocky Mountain Institute (RMI), a US-based organisation that works on energy innovation and sustainability.

“The world needs a radical change in comfort cooling technology, one that can effectively and assuredly offset the exponential increase in cooling energy demand and put us on a path to cooling with less warming,” the authors write.

To encourage innovation and scale up energy-efficient home air conditioning, RMI teamed up with India’s Department of Science and Technology (DST) and Richard Branson, British entrepreneur and philanthropist and others, and launched the Global Cooling Prize.  The competition—for two years and funded to the tune of $3 million—envisions an air conditioner with 80 per cent less greenhouse gas emissions and coolants that are not greenhouse gases. (India committed itself to the Kigali Amendment to the Montreal Protocol, an international effort to phase out HFCs by 80 per cent by 2030. India was given $44.1 million from multilateral fund to help manage the transition to alternatives.)

India has up to 2028 to start phasing down HFCs. Many companies are already working on less damaging coolants. In the Indian market, Godrej Appliances produces one of the most efficient room ACs. Its greenhouse gas emissions are about 70 per cent lower than the market average, consumes 60 per cent less energy, and uses a coolant that has lower global warming potential.

“It is possible to solve the global cooling challenge and enable thermal comfort for all without warming the planet: the solution lies in a breakthrough cooling technology with five times less climate impact,” the report notes.

India launched its “India Cooling Action Plan” (ICAP) in 2018. Its goal is to “reduce cooling demand across sectors by 20% to 25% by 2037-38, reduce refrigerant demand by 25% to 30% by 2037-38, reduce cooling energy requirements by 25% to 40% by 2037-38, recognise “cooling and related areas” as a thrust area of research under national S&T Programme, and training and certification of 100,000 service sector technicians by 2022-23, synergizing with Skill India Mission.”

The report says that sensitising consumers about the operating versus first cost of efficient equipment is only part of the solution. Public awareness is an essential part. “Public awareness about how cooling is connected to climate change and pollution has to be elevated to a level where buying a super-efficient appliance is no longer only a first-cost-based decision, but one that the consumers base on lifecycle cost and the health and well-being of their children.”



ir conditioning has wrought many changes in India. It did away with many traditional architectural features of houses in India. Instead, it helped build apartment towers, office blocks and houses that look like boxes on a big scale.

Researchers like Rajan Rawal are working towards keeping the AC in its place. “Access to a thermally comfortable environment is as important as access to clean water and air,” Rawal unveils his philosophy of cool. He is a professor at the Centre for Advanced Research in Building Science and Energy, CEPT University, Ahmedabad.

“A newer way of thinking is a must, we need to talk about comfort and not cooling, thinking of cooling leads to cooling of air (change in properties of air), but when we think about comfort, we think of physiology, psychology, and behaviour of human beings, not just changing property of air.”

“When we say thermal comfort, it means a state of mind, where the three things count.”

 After the invention of the AC in 1902, and during the 1930s, researchers tried to understand at what temperature a human being would be comfortable, and came up with a suggestion that around 24C would be comfortable.

Unlike Europeans who’re comfortable between 22 and 27 degrees C, our band of tolerance is higher, between 18 and 32. That’s how we have been interacting with nature since historical times.

Rawal says that is not the actual case. When you go to the theatre, you start freezing, that is, you’re uncomfortable towards the cooler side. When you go to the market or any warm outdoor place, you may feel uncomfortable towards the hotter side.

“Uncomfortable towards hotter side, towards cooler side. Thermal comfort works both ways because our bodies work in tandem with nature.”

Hence people born and brought up in colder countries cannot tolerate heat, whereas people from tropical countries do have an inclination to tolerate heat, to a certain extent, he explains.

Their research was published in 2016 in Elsevier’s Building and Environment Journal. Till its publication, India followed a convention not meant for India. The findings of the paper have become national standard in India, and part of Building Code.

“Unlike Europeans who’re comfortable between 22 and 27 degrees C, our band of tolerance is higher, between 18 and 32. That’s how we have been interacting with nature since historical times.” However, Rawal expects changes in Indians’ tolerance levels in the next 50 years.

“Because we’re exposing ourselves to tighter environments, people may change.” A person entering an air-conditioned office at age 20 will have an altered tolerance level later. Instead of keeping AC switched on 24x7, Rawal says good ventilation will help.

“Let air move inside your house when outdoor air is cooler; when outdoor becomes warmer, you need to shut your windows and rely on a ceiling fan or air conditioner,” he says. The former moves the air, while the latter cools it.

“What happens is that AC starts to cool the house before it cools you. That’s where energy is wasted.” Moreover, home appliances themselves generate a great amount of heat.

Rawal says office ACs that work in concurrence with outdoors increase productivity and health of occupants. “People in an office could be from different areas, having different thermal sensitivities. Thermal sensitivity in males and females is  different because of metabolic rates.”

Occupant behaviour mapping should be used to find out thermal comfort, he suggests. Based on that, you maintain a certain temperature and provide a ceiling fan or pedestal fan. “That makes people comfortable, happier, and more productive.”

He suggests other options for cooling instead of AC, depending on places: desiccant cooling or dehumidification, where you use a device to suck moisture out. It is useful in humid coastal regions. Evaporative cooling, where you add some moisture in dry places like Jaisalmer or Jaipur. Natural ventilation and night-time purging of heat by using filters and opening windows. There is also passive cooling which uses non-mechanical methods to maintain thermal comfort in the building.

Abhyankar too is hopeful of more sustainable cooling solutions, with rapidly falling solar and wind prices. With better building design (more efficient materials, passive and adaptive cooling, white roofs etc) and better urban design, we can reduce the need for air conditioning in the long run. “Unfortunately, with rapidly rising temperatures, we need to act soon.”

Indians’ liking for cool, still, dry air that comes from AC could work against us, in terms of more warming of atmosphere and less comfort in remaining in our own skin.