Why a sari is both hot,
and cool
Indian garments like the sari, dhoti and lungi
adapt beautifully to varied weather conditions, shows research
Only a Bollywood heroine can cavort around the
Alps in a chiffon sari without losing her extremities to frostbite. But the
idea may not be as ridiculous as it seems.
The sari, says fresh research, can alternately
cool and warm a body simply in the way it is draped.
Dr Madhavi Indraganti, a Hyderabad-bred
architect and scholar who teaches at the Prince Sultan University in Riyadh,
has established that the sari is all-weather wear in a paper published in a
peer-reviewed journal Architectural Science Review.
The nub of it is: you can go from summer to
winter in the same sari, and you'll have all-round comfort just by making small
changes with the pallu and a few add-on accessories. And it is not just the
sari that is weather-versatile Indian wear.The four-yard dhoti, the twoyard
lungi and the pancha (dhoti tied through the legs) are all capable of shielding
the body from extreme heat and cold to varying degrees, says Indraganti.
“When comparing Indian thermal comfort data from
the field, I wanted to know the exact value of the clothing insulation of the
sari (standard insulation values have been derived for almost every article of
clothing and common clothing ensembles in the world), but there were no
published standards for the sari, says Indraganti. Computing the insulation
value of indigenous clothing (measured in units called `clo') can help
researchers prescribe more accurate thermal comfort models for India. The
insulation value of the sari has been determined earlier but only Indraganti
had studied it in its various drapes.
In 2013, on a Fulbright-Nehru Fellowship,
Indraganti collaborated with other scholars to conduct a year-long study on the
sari. She tested two saris, a lightweight yellow silk Kalakshetra sari from
Tamil Nadu, and a heavier green polyester sari from Gadag, Karnataka. These she
draped around a female thermal manikin called Monica, in the common Nivi style,
with the length wound around the body from right to left, pleated in the front
at the waist, the pallu swept back over a shoulder.
The $200,000 thermal manikin contained a heat
engine which could simulate the temperature of the human body and its thermal
responses to stimuli like humidity , room temperature, ventilation, and
clothing insulation. Maintaining the chamber temperature at 20 degrees, and Monica's
skin temperature at 34 de grees, the team outfitted her in nine ensembles
complete with undergarments, a sari under skirt and bodice. The ensembles corre
sponded with the way saris are usually draped in summer, monsoon and winter.
The results showed that the sari can handle a
wide range of weather condi tions. The clothing insulation values were
increased by as much as 47% just by changing the drape on the upper body alone.
Winter drapes provided al most as much insulation as coveralls, long-sleeved
thermal underwear and long underwear bottoms. The sum mer and monsoon ensembles
simi larly came close to the Western pairing of turtleneck blouse, skirt, socks
and formal shoes.
“You can reduce the clothing insulation of a
sari to the value of a pair of knickers and take it up to that of a three-piece
suit,“ remarks Indraganti.
In field studies, she'd seen do mestic workers
lift the sari hem up some inches to the calves by tucking the pleats into the
waistband. This created more legroom and im proved air circulation up the legs.
Indraganti points out that women can wear a
sweater over the blouse when it's cold, the way she did in Japan at 5 degrees
Celsius, or drape the pallu over their heads the way they do in Jaipur and
Rajasthan to pro tect against a severe sun.
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Joeanna Rebello
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TOI15MAR15
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