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Too cool for comfort

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May 15, 2013 | From the print edition

How rising incomes are lowering room temperatures at the cost of energy, health and comfort

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“I can’t imagine my day without air-conditioners. I even ensure that I buy vegetables and fruits from an air-conditioned supermarket,” says 28-year-old Deepali Sinha Kapoor, a marketing executive in an IT firm in Lucknow. Kapoor is so used to cool spaces that besides spending long hours in her air-conditioned office, she spends her weekends touring air-conditioned malls.

Like Kapoor, many young people and families crowd malls and multiplexes in the summer to escape the heat and revel in crisp air-conditioned comfort. Manufacturers, cashing in on the summer frenzy for air-conditioners (ACs), dole out attractive offers. Originally, it were manufacturers of products susceptible to heat and humidity, like tobacco, chocolate and colour printing, who had commissioned experiments in mechanical cooling. Emphasis has shifted to comfort systems, with air-conditioning aimed more at cooling living space than equipment and consumer items.

Higher disposable incomes and accompanying lifestyle modifications are major drivers of the demand for ACs in India. “People want to feel comfortable both at home and at their workplaces and ACs provide them this comfort,” says Anup Bhargav, senior general manager, Godrej Appliances.

A study by Mckinsey Global Institute (MGI) states the middle class in India will swell from 50 million at present to about 583 million by 2025. That will be 41 per cent of the population. This upwardly mobile middle class is likely to use ACs, vacation annually, dine out and opt for global brands, according to MGI. Small wonder then the AC market in India is growing at over 30 per cent annually.

Rising expectations

Studies show that living and working in buildings with strictly controlled temperature conditions raises thermal comfort expectations. People become accustomed to air-conditioning and do not want to settle for anything less. India is beginning to show signs of this discomfiting trend.

“Overindulgence in air-conditioning has made people its captive users and they hardly venture outdoors,” says S K Chhabra, head of cardio-respiratory physiology, Vallabhbhai Patel Chest Institute in Delhi. “A large number of parents that come to us for admission enquire about air-conditioned classes. Today it is a matter of competition and fully air-conditioned schools score over others,” says Richa Khandelwal, a counsellor at Euro Kids, India’s largest preschool chain.

good living Some architects believe that Indians need to use ACs only during the peak summer months. A well ventilated room with a fan at maximum speed can provide adequate comfort the rest of the year. The demands of modern living have substituted traditional commonsensical measures, such as wearing light clothing, eating light and taking afternoon siestas, with more energy-intensive cooling mechanisms.

“Medical science has established that being exposed to a wide temperature range allows the body to be more resilient in the face of variation. Instead, most people today prefer to have an artificially controlled environment through mechanical cooling,” says architect Gaurav Shorey. “What’s even worse is that people wear three-piece business suits or stretch jeans and then run ACs at 19°C to keep themselves cool. What is it that stops them from wearing a cotton shirt or a kurta which can keep the body cool naturally,” asks Shorey.

Inconsistent norms

Building norms do not sufficiently address thermal comfort. The National Building Code of India (NBC) 2005 describes human thermal comfort as a condition of surrounding thermal environment under which a person can maintain a body heat balance at normal body temperature without perceptible sweating. It depends on factors like age, metabolic rate and clothing, which in turn are affected by air temperature, relative humidity, radiation from solid surroundings and rate of air movement.

The tropical summer index (TSI) is a tool that helps determine the combination of variables such as temperature, relative humidity and air velocity that makes a person feel comfortable. NBC states that the thermal comfort of a person lies between TSI temperature values of 25°C and 30°C with optimum condition at 27.5°C. But for air-conditioned spaces the same code proposes an indoor temperature range of 23-26°C for summers and 21-23°C for winters.

The Bureau of Energy Efficiency’s Energy Conservation Building Code (ECBC), which aims to regulate energy consumption of commercial buildings that usually have ACs, does not define temperature and humidity standards. “Ideally, codes should specify the range of temperature conditions specific to the climate,” says Rajan Rawal, coordinator, Centre for Advanced Research in Building Science and Energy at CEPT University in Ahmedabad. In one of his studies Rawal highlights that without thermal comfort standards customised for Indian climatic conditions, air-conditioned office buildings in India operate at 22.5 (± 1°C). Consequently, mechanical systems have to use massive energy to cool temperatures down from 42-45°C to 21-22°C.

Health effects

“Well conditioned spaces encourage people to work longer and more productively,” says Bhargav. However, a 2004 Cornell University study highlights that uneven airflow in cooled buildings often leaves some people shivering and others sweating in corners, thus affecting their performance at the workplace.

“For almost three months all I did was sneeze and cough throughout the day,” smirks Zubaan Syed, an aspiring architect. “After living in Puducherry for a year without any ACs my body got rude shocks everywhere in Delhi where ACs were always on. Doctors made me undergo all kinds of expensive tests and prescribed a host of medicines, but nothing seemed to be working,” he adds.

The Indian AC market, however, seems to be in good health. According to a study by the Associated Chambers of Commerce and Industry of India, the room AC market in India was estimated at 4.2 million units in 2011 and was valued at Rs 7,200 crore. The demand for ACs is shifting from big metropolitan cities to medium and small cities. “The residential segment is growing rapidly at the rate of 8-9 per cent, with greater demand for spilt ACs,” says Bhargav. A growing number of Indian and international studies highlight the perils of excessive air-conditioning on human health. Chhabra cautions that a sedentary air-conditioned lifestyle could cause obesity, cardiovascular diseases and psychological infirmities. A preliminary study done by a team of doctors from various medical colleges in India found the frequency of respiratory symptoms like coughing, wheezing and breathlessness was higher among AC users.

“Now that summer is back with ACs roaring on maximum, I am afraid that my problems may reappear,” says Syed. “Maybe this time I will carry a jacket and a cap around.”

AddThis

Raising the set-point temperature for cooling by air-conditioning from 21-22°C to 25-26°C can itself bring significant savings in the energy consumption for cooling. The users of the air-conditioned space should be more responsive to the ambient conditions and should be the able to regulate the air-conditioning depending the type of usage and out-door climatic conditions.

9 May 2013
Posted by
Seema Devgan

Excellent article. I learnt that out of 2700 MW power per day for Mumbai 1000 MW accounts for Airconditioning. Can't future Government offices be more Eco friendly and less power consumption?
Dr.A.Jagadeesh Nellore(AP),India

4 July 2013
Posted by
Dr.A.Jagadeesh

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