Passive heat mitigation possibility using meteorological data analysis of Phitsanulok Province, Thailand for building application in the tropics

Abstract

Climate is characterized by the outdoor temperature and precipitation. The Equatorial climate, found in the tropics, presents a hot and humid climate that is commonly observed in Thailand. The maximum outdoor air temperature increases due to the increase of the global temperature. This will cause building energy demand to grow according to the increased utilization of air conditioners, the highest energy consuming appliance in buildings. This paper presents an investigation in the possibility of passive heat mitigation by analyzing meteorological data in Phitsanulok, Thailand, a city located in the tropics. Passive cooling techniques operate without a conventional energy supply and rely on weather parameters. The air temperature, relative humidity, wind speed and direction, and solar angles were employed for the analysis. Data recorded in 3 h intervals from 2014 to 2016 was retrieved from the meteorological department of Phitsanulok. The wind speed, outdoor temperature, and humidity were used to evaluate the ventilation potential. A sun path diagram was adopted to demonstrate the solar angles on buildings. The solar angle differs from one location to another and varies with the time of day and throughout the year. The simulated results can assist in the design of awning and/or roller blinds on fenestrations. The results indicate the period when natural ventilation can reduce the amount of mechanical cooling required, thus cutting down the energy consumption of buildings. The results showed around 20 to 30 percent annual energy savings could be achieved when natural ventilation is employed, while maintaining human comfort. Furthermore, shading devices can prevent sunlight from entering buildings and reduce the ensuing heat build-up, thus further reducing the energy needed.