Plan residential areas better to reduce effect of heat: Study

MUMBAI: Layout of buildings along with green spaces play an important role in determining how a locality heats up due to the urban heat island (UHI) effect, says a study by the Indian Institute of Technology – Bombay (IITB). The study calls for changes in the way residential areas are designed to reduce the UHI effect – a phenomenon in which built-up areas are warmer than surrounding semi-urban and rural areas.

Deploying 12 low-cost sensors across five building types in Mumbai, the research team at the Centre for Urban Science and Engineering (CUSE), IITB, led by professor Ronita Bardhan and her PHD student Surabhi Mehrotra found thermal hotspots over buildings constructed by the Slum Rehabilitation Authority (SRA) and slum areas after sunset (6pm) and during early morning (6am). These residents are exposed to higher-than-normal temperatures or UHI effects between 12am (midnight) and 6am because heat trapped during the day gets radiated in the night.

On the other hand, high-rise apartments and medium-rise buildings occupied by high-income and middle-income groups undergo heat stress during noon when the sun’s radiation over the earth’s surface is at its peak.

“UHI effect has a causal relationship with energy consumption because the more a building type gets heated during the night, residents tend to use air-conditioners or mechanical ventilation,