Gujarat searched for ACs at 30.5C, MP at 25.9°C

AHMEDABAD: At what temperatures do we begin an internet search with the words ‘air conditioners’ or ‘air cooler’— or in other words, begin looking for a cooling appliance? A team of researchers have used Regional Internet Search Frequencies (RISF) to suggest that across 17 states in India, internet searches can be an indicator to derive thermal discomfort thresholds, which is dissatisfaction with the thermal environment.
The study showed that the “state-level heat thresholds ranged from 25.9C in Madhya Pradesh to 30.5C in Gujarat and 31.0C in Orissa.”



The study conducted by Tanya Singh of Wageningen University and Research, Netherlands, Christian Siderius of London School of Economics and Ype Van der Velde of VU University Amsterdam, states that local adaptation of individuals was found to occur at state level.

“The higher the average temperature in a state, the higher the heat threshold; and the higher the intra-annual temperature range (warmest minus coldest month) the lower the heat threshold,” claims the research work.

Kerala, for instance which had the median heat threshold of 30.7C, the second highest of all states, had the lowest explained temperature variance of ‘1C’. The study also observed that most air-conditioners in Indian office buildings are still operated at temperature levels around 22.5C all year round. The researchers had visited Cept University for their study.

Executive director of Centre for Advanced Research in Building Science and Energy (CARBSE) at Cept University, Dr Rajan Rawal, said, “What makes your body uncomfortable during peak afternoons is the sun’s radiation directly falling on your skin.” He also explained how the humidity ratio and air velocity also plays a major role in reducing or accentuating heat intensity.

The threshold study also found that states that have a larger temperature difference between winter and summer show a lower heat threshold, indicating a lack of short-term acclimatisation during the transition phase between winter and summer. This might make people in those states more sensitive to heat as compared to people who are exposed to high temperatures throughout the year.