C19 -- A Comparative Study of Embodied Carbon and Thermal Performance of New Lightweight Construction Technologies to Conventional Construction Technology in Affordable Housing in India

This paper attempts a comparative analysis of embodied carbon and thermal performance of new lightweight construction technologies of the GFRG Panel system, EPS core Panel system, AAC blocks, and fly-ash bricks with conventional construction of burnt clay brick walls with RCC roof in the composite climate zone of Delhi, India. To cater to the huge affordable housing demand in urban India by 2030, it is crucial to mainstream speedy alternate construction technologies that are low in embodied carbon and ensure thermal comfort for the occupants. The study involved first creating a data inventory on thermo-physical properties and global warming potential for the identified construction. A typical EWS housing unit is modeled in Design Builder for conducting thermal simulations. On-site air temperature and globe temperature data loggers were put in the worst-case scenario to measure the real-time indoor operative temperature in two affordable housing units made of burnt clay brick walls and AAC walls in Delhi to validate the developed model. Simulations were carried out for all the walling and roofing material combinations on the validated model. All the material combinations have also been examined with 25mm (0.98 in.) thick EPS insulation. The resulting indoor operative temperatures are compared with the comfort bands given by IMAC-R (2022) and ASHRAE-55 (2020) to assess the annual and summer discomfort degree hours for the peak summer month of June. The volume of each walling and roofing material assembly is calculated from the case study flat to calculate the embodied emissions from the GWP potential (Kg CO2 eq.) of each material. The study discourages the use of burnt clay bricks due to high embodied carbon, recommending fly ash bricks, AAC blocks, and EPS core panels. EPS core panels used in walls and the roof together exhibit optimal thermal performance with low embodied emissions. GFRG panels are low on embodied carbon but need insulation for thermal comfort. The study informs decisions on the large-scale adoption of lightweight construction materials and technologies for affordable housing.