Impact of thermal behaviour of different environmental conditions on ambient environment and thermal discomfort in Malaysia

Thermal behaviour of various urban environments may increase the surrounding temperature and induce the urban heat island phenomenon. This study carried out local climatic measurements on different urban environments and evaluated their thermal comfort performance. The monitoring sites were selected on the basis of the characteristics of vegetated area, built-up environment and open space areas. Results showed that the temperature variations between vegetated areas and open spaces were lower on average at about 5°C and 3.5°C, respectively. The higher temperatures in built-up areas may be due to higher solar radiation exposure and reflection of long wave radiation from adjacent buildings. Meanwhile, the open space faced the sky with no building obstructions and allowed a free flow of wind to cool down the surface temperature through convection and radiation. Furthermore, the discomfort index was calculated and its value lay within the category of ‘partially comfortable’ where people have adjusted to the local climate. Thus, urban greenery, the use of high albedo surface materials and proper implementation of urban geometry are important elements for a sustainable urban development with improved thermal comfort