Roundtable discussion on “Human thermal comfort standards and approaches in buildings for energy efficiency and sufficiency in buildings”

Date: August 9, 2018.

Venue: Centre for Science and Environment

The Sustainable Buildings and Habitat Programme held a roundtable discussion on “Human thermal comfort standards and approaches in buildings for energy efficiency and sufficiency in buildings” on August 9, 2018. It was attended by selectgroup of architects, regulators, professionals, civil society and building industry who are working on sustainability of the building sector. Some notable participants were Prof Rajan Rawal (CEPT University), Tanmay Tathagat (Environmental Design Solution), Sanjay Prakash (SHiFT Studio), Anju Singh (Bureau of Energy Efficiency) among others. 

This discussion has become important as several energy efficiency measures are being framed for mechanical cooling or air conditioning systems including energy efficiency standards and rating; fixing of the default temperature set points in room air conditioners and for centralized cooling systems; ECBC amendment to set internal operative temperature according to the adaptive comfort model among others. But all these initiatives are governed by a singular requirement of delivering on desired and adaptive human comfort. But the approaches to defining thermal comfort remains uncertain even though this is expected to be a regulatory parameter for designing of buildings and for manufacturing of air conditioning systems.  

Regulatory efforts are already underway, as by the BIS, to define comfort based on ambient temperature, humidity and air flow within a climatic context. But questions have come up regarding the adequacy of the current approaches to defining comfort as a regulatory tool for different climate and building types and how this needs to guide energy efficiency standards for mechanical cooling systems? Temperature setting for mechanical cooling in buildings for instance, has implications for energy consumption – lower set points come with high energy penalty. But defining comfort also has implications for bio-climatic buildings without mechanical cooling.  

This roundtable was first in series of engagement planned by CSE to build public and policy dialogue to demystify the concept of comfort as defining criteria for buildings in different climatic conditions and building types to improve energy efficiency and sufficiency equitably. We are investigating issues related to thermal comfort standards to understand an optimum comfort vs. environmental balance and benefit that will work for India.