Aditi Agarwal


Aditi Agarwal, MDes EE.  TOO HOT TO STAY AT HOME:
Residential heat vulnerability in urban India.  Images: 3 maps of india showing current climate conditions, 2050 projected temperature increases of` 1.8° Celsius, 202 population.
Graphs showing Typical Summer Day temperatures and bar graphs displaying current above and below comfort levels and future projections.  ABSTRACT:
Recent climate trends show that India could suffer from deadly heat waves within a few decades, bring portions of the sub-continent close to the threshold of survivability, and accelerating the demand for cooling. The share of space cooling in peak electricity load is projected to rise sharply in India. Simultaneously, the country’s population is expected to continue to grow, peaking by mid-century. Rapid urban development, particularly mass production of affordable housing presents an opportunity to optimize the design of building envelopes. This will minimize the demand for active cooling while keeping the inhabitants safe, even during periods of prolonged heat stress.
Heat vulnerability is a public health and safety concern. A recently launched building energy code for India,  Residential ECBC (Eco-Niwas Samhita 2018) limits the thermal transmittance of the envelope. Its aim is improving thermal comfort in non-air-conditioned apartments while reducing the health-related heat wave impact. However, the code’s simplified approach has limitations, for example, requirements do not vary with climate zones within the country. Additionally, it is not adapted to future climate conditions where parts of the country are expected to be too hot in summer for over 74% of the time. This study focuses on indoor occupant comfort and the severity of overheating during summer, in common building assemblies in the hot and dry climate zone. The analysis intends to illustrate the problem and avoid a longterm lock-in of inefficient, high energy-consuming residential buildings.  • Rising temperatures globally are leading to an exponential increase in cooling demand. 
• Mass production of affordable housing in India can exacerbate the problem. 
• Opportunity to improve envelope performance and minimize need for active cooling, thus avoiding long-term lock-in of inefficient homes. 
Key words: thermal comfort, heat vulnerability, passive survivability, envelope performance.