Critical Review of Standards for Indoor Thermal Environment and Air Quality

Quality of the indoor environment has become an important parameter to account for in new and ex- isting buildings due to the increasing number of people spending most of their time indoors. Generally, the design and evaluation of indoor environments in buildings rely on appropriate guidelines and recom- mendations. National and international IEQ standards specify indoor environmental conditions considered acceptable to most occupants. This publication reviews and critically compares the requirements for in- door thermal environment and ventilation for acceptable air quality across international standards such as ISO, EN and ASHRAE and national standards of China, India, Singapore, and Australia. The critical analysis of IEQ standards demonstrates that regional differences and diversity factors due to factors such as climate, building typology, demographics, and culture might not be appropriately ad- dressed both in national and international standards, limiting the feasibility of universal indoor environ- mental criteria. In addition to that, most of the standards provide recommendations for various categories of thermal comfort and air quality by focusing on the perception of IEQ by occupants rather than pro- ductivity and wellness as quantitative criteria. The review shows that thermal comfort and air quality pa- rameters are treated separately and without an integrated assessment of various environmental quality- related dimensions. Therefore, there is a need for a method to combine various indoor environmental factors into a combined indicator.