EFFECTS OF VEGETATION AND PCM IN REDUCING URBAN HEAT ISLAND

Abstract

Globally, fast-tracked urbanization has led to diversified environmental challenges since the time of the industrial revolution. Among the challenges faced, Urban Heat Island (UHI) is caused by the replacement of natural materials with man-made ones such as concrete, asphalt, and increased anthropogenic heat production, among other factors. This study is on understanding the reasons behind UHI, its effects, and finding out proper strategies for mitigation in the context of Bangladesh. Among many ways, proper interior and exterior vegetation, sufficient wind flow, and appropriate building materials are chosen to be the proper methods to reduce UHI effects in Bangladesh. CFD analysis has been carried out to understand the effect of vegetation, wind flow, and different material to mitigate UHI. An estimation of the effect of temperature reduction in energy efficiency is also done. It is observed that a significant amount of energy can be saved by reducing the cooling load if these suggestions are followed. The study shows that the temperature is decreased up to 3°C with the increasing vegetation on exterior walls and rooftop. By using Wood Plastic Composite (WPC) on the rooftop as a phase change material, temperature is decreased around 4°C. By using all conditions (rooftop, sidewall, interior vegetation & PCM on rooftop) together temperature could be mitigated around 5°C.