Comparison of reflective coating with other passive strategies: A climate based design and optimization study of building envelope

Abstract

The building envelope modification in terms of insulation material, glass material, orientation, window to wall ratio (WWR), reflective coating, etc., is vital to control the heat penetration in buildings. This article evaluates the effect of Passive methods (PMs) (such as windows layers, window colors, infiltration, insulation material, insulation location in wall and roof, and orientation) in the first scenario in controlling the heat gain by building envelope for 18 cities from different Indian zones of climate. Further, the study investigated two more scenarios of passive implementation, the second scenario is a reflective roof (RR) coupled with PMs, and the third scenario is a reflective roof and wall (RRW) associated with PMs in controlling the thermal environment. The second and third scenarios also evaluated the impact of reflective surfaces on the requirement of insulation thickness for the roof and wall. This work advances the sustainability potential by optimizing critical building design parameters utilizingthe Non-dominated Genetic Algorithm (NSGA-2), which reveals a considerable reduction in required energy demand. The mean absolute percentage error (MAPE) for average hourly temperature data collected between March 14 and March 18, 2022, is 4.18 with computational results. The obtained outcomes exhibit that PMs save 6–29 % of HVAC energy annually. Where infiltration rate for all climates except cold climate is 0.2 ACH; however, cold climatic cities are perceived in the range of 0.6–0.8 ACH and 0.2–0.4 ACH for Shillong and Srinagar, respectively. It can also be stated that double-layer green 6 mm/13 mm air windows would give the best optimum solution for all climates. A coupled system of PMs and RR has demonstrated an energy savings potential of 11–32%, depending upon the climatic regions. The obtained outcomes from PMs and RR coupled systems also significantly reduced insulation thickness.