The Effects of Solar Reflectance Index (SRI) on Roof Tiles for Climate Change Mitigation

• Main Author: Mohd Nawawi, Mohamad Helmi
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2011
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://utpedia.utp.edu.my/10358/1/2011%20-%20The%20effects%20of%20solar%20reflectance%20index%28SRI%29%20on%20roof%20tiles%20for%20climate%20change%20mitigation.pdf; http://utpedia.utp.edu.my/10358/

Temperature rise is a global phenomenon that has been occuring for a long time. This is due to the development that occurs everywhere around the world. As human continue their pursue of the latest technology and the tallest skyscrapper, we tend to neglect the negative impact it has on the world. Although we cannot dismiss the importance of developing a nation, we also need to ensure mitigation methods in order to cope with the ever-rising temperature. We tend to cope with this issue by using more air-conditioning units in our residents and work places. Green house gasses emission caused by excessive usage of air-conditioning units is one of the factors that cause the temperature rise. These gasses are one of the factors of global warming. Urban Heat Island effect is a huge problem that occurs in rural and urban areas. It is the effect of excessive heat gain on buildings. During the peak heat of the day, the temperature of an exposed area might rise up to 50°C [19]. Since the roof affects more of the heat gain compared to the envelope (walls) of a low-rise building, we conducted the experiment only on the roofs. A method that can be used to reduce the usage of air-conditioning units is by choosing light colored roof tiles, which has high SRI value. A standard white color has the SRI value of 100 while a standard black color has the SRI value of 0. Solar Emittance and Solar Reflectance affect these values with both ranging from 0 to 1. By choosing lighter colors, we can manage to reduce heat absorbtion of our building, especially during the peak heat of the day. The experiment consists of four roof tile colors, which are white, orange, dark brown and light grey. The data compared for these colors are the ambient temperature, indoor temperature, solar irradiation and relative humidity. The experiment was conducted at an experimental house with the size of 3m x 3m x 2.5m. The instruments used are a solarimeter, a multimeter and an internal automatic data logger. The duration of each color was six days.