For heat relief, India turns to 'desert coolers'

Hot? You think you know hot?

Texans may brag about the biggest heat. New Yorkers can complain about their scorchers. But during the summer, don't wag those chins at anyone living in New Delhi.

In the United States, people moan and melt if the mercury rises above 100 degrees F. Here, a cold front is when it drops below 100.

So whether by human perspiration or divine inspiration, the local population here - numbering in the several hundreds of millions - has developed a solution to nature's annual summer sizzle.

Indians call it "the desert cooler." Or, in a different vernacular, the boxy refrigerator-sized contraption is known as "the poor man's air conditioner."

While not as effective as standard A/C, desert coolers do take the edge off the heat. They are also cheaper, use far less electricity, and don't need environmentally harmful chemical coolants.

All over Delhi, and much of the rest of the country, the popular water-fed coolers jut out from the backs of apartments, servants' quarters, and government offices.

At the end of the day, as the sun goes down, millions draw the shades and gather in front of the cooler fan for traditional summer fare like watermelon and lime water. If you are one of the 98.5 percent of the population that can't afford iced tea at the Hyatt, chances are you and your family will eat, discuss local issues, watch TV - even sleep en masse - lulled by the breezes of this local wonder machine.

What makes the cooler remarkable is its simplicity, cheapness, and effectiveness. Your basic cooler is a large steel box with bamboo or wood-chip mats covering three open sides. Water is poured into a tray at the bottom, and is pumped up and sprayed out so that it trickles down the mats. An electric fan inside completes the task by blowing out air that is cooled by water evaporation as it passes through the wet mats.

A similar device known as a "swamp cooler " - a box with a fan that blows air through a water-soaked mesh screen - became popular through the 1940s in the US and is still used in the desert Southwest.

India's desert coolers make a slightly gurgly sound, not unlike a household aquarium. Some find this irritating, but at least one graduate student, who stretches out each night in front of a cooler, confesses that he can't fall asleep without the burbling noise. Another problem is the increased humidity, which can affect high-tech appliances like televisions and computers.

A simple cooler can be built in about four hours. And once the weather gets hot, the orders pour in.

This year the heat hit so hard and fast that public schools closed for weeks and office hours were rescheduled. Hundreds of heat-related deaths were reported. The power drain from regular air conditioners was blamed for daily blackouts, so residents are now forbidden to use them between 6 a.m. and 10 p.m.

For the past decade, desert coolers have been signs of a certain blue-collar upward mobility among Indians.

Regular air conditioners of the American variety can cost 50,000 rupees ($1,100), a year's salary for many Indians. A good desert cooler, on the other hand costs between $45 and $100.

Then there are those shocking electricity bills. While a normal A/C costs about $4.50 a day to operate - the humble cooler runs all day for about 12 cents.

Families now use coolers as gifts of distinction in wedding dowries. Or, they might be the first big purchase of a newly married couple, especially if the arrangement is made for late spring.

Apartment shoppers no longer wonder what the huge hole in the wall or window frame is when they walk into a room - it is a cooler frame. But desert coolers recently have been made in smaller versions, even in plastic-molded models designed to resemble regular full-power A/C's - a sign of status.

The desert cooler has been selling only for about 15 to 20 years in India, but the theory behind it goes back centuries. The ancient Egyptians, Greeks, and Romans were known to hang wet mats over the entrance to tents and other dwellings.

At the Kamla Market in downtown Delhi, a typically chaotic and colorful smear of every kind of business from tire repair to orange juice squeezing, Rajinder, owner of the Great King Desert Cooler shop, claims the product hails from the northern Indian plains of Uttar Pradesh.

For hundreds of years, Indians there put up wet curtains instead of doors in the baking summer months. The curtains were made of a thick, tough grass called "khas;" servants would periodically douse the curtains with water, and the cross-breezes cooled down the house.

More recently in the modern desert cooler's evolutionary chain, locals began to drape the khas mats on top of their cars, reducing the heat inside from temperatures that would satisfy Nebuchadnezzar to a mere slow bake.

The problem is, desert coolers only work in dry heat. Indians must still find an answer for the humidity that will soon arrive with the annual monsoon rains. How about a poor man's swimming pool?