Performance Evaluation of Built Environment in Local Climate Zones

¹ Indian Institute of Technology Roorkee, India
² College of Engineering Trivandrum, India

^* corresponding author: angelvarghese96@gmail.com

Abstract

The thermal performance of a building is significantly influenced by the climate around it. It is observed that the microclimate of an urban area is notably different from that of the surrounding regions. This difference is mainly due to the variations in anthropogenic heat, built morphology and surface characteristics. The Local Climate Zone (LCZ) system, effectively classifies the urban areas concerning these climatic variations. This study comprises two sections; the first section explores the climatic differences across LCZs and the impact of urban built morphology on microclimate. For this, three different LCZs – LCZ-2, LCZ-5 and LCZ-9 (high, medium and low density respectively) were modelled within the range of values prescribed in the LCZ system and an analytical study was carried out with the help of the CFD tool – ENVIMET. To understand the influence of urban morphology features on microclimate, LCZ-2, a representative LCZ was chosen and a parametric study of variations in morphology variables was carried out. It was observed that incidence angle, surface characteristics and H/W greatly influence the microclimate. The second section of the study explores the thermal performance of the built environment across the LCZs. A typical 3-bedroom residential building was considered and thermal performance evaluation of the same in three different local climatic conditions was carried out through field measurements. It was observed that heat flux in LCZ-5 (65.5 W/m²) is high compared to that of LCZ-2 (16.6 W/m²) and LCZ-9 (6.04 W/m²). The study points to the significance of location-specific building performance studies and design criteria.