Opinion: Culturally defined coolingPOSTED: 08/28/12 11:37 AM
The blackouts that left hundreds of millions of Indians sweltering in the dark last month underscored the status of air-conditioning as one of the world’s most vexing environmental quandaries, Elisabeth Rosenthal wrote in the New York Times. Her story reflects the alarm we have been sounding over the liberal way air conditioning systems are used in St. Maarten. Let’s follow Rosenthal’s lead here:
Fact 1: Nearly all of the world’s booming cities are in the tropics and will be home to an estimated one billion new consumers by 2025. As temperatures rise, they — and we — will use more air-conditioning.
Fact 2: Air-conditioners draw copious electricity, and deliver a double whammy in terms of climate change, since both the electricity they use and the coolants they contain result in planet-warming emissions.
Fact 3: Scientific studies increasingly show that health and productivity rise significantly if indoor temperature is cooled in hot weather. So cooling is not just about comfort.
Sum up these facts and it’s hard to escape: Today’s humans probably need air-conditioning if they want to thrive and prosper. Yet if all those new city dwellers use air-conditioning the way Americans do, life could be one stuttering series of massive blackouts, accompanied by disastrous planet-warming emissions.
We can’t live with air-conditioning, but we can’t live without it.
“It is true that air-conditioning made the economy happen for Singapore and is doing so for other emerging economies,” said Pawel Wargocki, an expert on indoor air quality at the International Center for Indoor Environment and Energy at the Technical University of Denmark. “On the other hand, it poses a huge threat to global climate and energy use. The current pace is very dangerous.”
Projections of air-conditioning use are daunting. In 2007, only 11 percent of households in Brazil and 2 percent in India had air-conditioning, compared with 87 percent in the United States, which has a more temperate climate, said Michael Sivak, a research professor in energy at the University of Michigan. “There is huge latent demand,” Mr. Sivak said. “Current energy demand does not yet reflect what will happen when these countries have more money and more people can afford air-conditioning.” He has estimated that, based on its climate and the size of the population, the cooling needs of Mumbai alone could be about a quarter of those of the entire United States, which he calls “one scary statistic.”
It is easy to decry the problem but far harder to know what to do, especially in a warming world where people in the United States are using our existing air-conditioners more often. The number of cooling degree days — a measure of how often cooling is needed — was 17 percent above normal in the United States in 2010, according to the Environmental Protection Agency, leading to “an increase in electricity demand.” This July was the hottest ever in the United States.
“Cooling is the craze in India — everyone loves cool temperatures and getting to cool temperatures as quickly as possible,” Rajendra Shende, chairman of the Terre Policy Center in Pune said. “Cooling has become such a cultural priority that rather than advertise a car’s acceleration, salesmen in India now emphasize how fast its air-conditioner can cool.”
Scientists are scrambling to invent more efficient air-conditioners and better coolant gases to minimize electricity use and emissions. But so far the improvements have been dwarfed by humanity’s rising demands.
Studies by Shin-ichi Tanabe, a professor of architecture at Waseda University in Tokyo who has long been interested in “thermal comfort,” found that while workers tolerated dimmer light just fine, every degree rise in temperature above 25 Celsius (77 degrees Fahrenheit) resulted in a 2 percent drop in productivity. Over the course of the day that meant they accomplished 30 minutes less work, he said.
Wargocki says that studies have found that with office temperatures between 82 and 86 degrees Fahrenheit (28 to 30 degrees Celsius), symptoms like headache, drowsiness and difficulty concentrating increase, which may explain drops in performance.
All these numbers indicate that temperatures just below 25 degrees Celsius are just fine for office workers. But in St. Maarten civil servants and even supermarkets keep their places much, much colder. We once sat in an office where its owner worked in 16 degrees Celsius. Go figure.
Office temperatures in the mid to high 70s Fahrenheit (23 to 26 Celsius) should be fine, Wargocki says. The comfortable temperature for sleeping (naked) is around 84 Fahrenheit (29 Celsius), one Japanese researcher says, if a fan is on.
Those suggestions are a good deal warmer than the norms in the United States, which underlines cultural differences in cooling preferences. In this sense the airco aficionados in St. Maarten are following the American cooling tradition. That’s not only unfortunate, it’s also expensive.