Numerical Investigation of Ground Cooling Potential for Malaysian Climate

Abstract

In equatorial countries like Malaysia, the cooling of buildings is almost entirely dependent on air-conditioning, with electricity as the main source of the energy required. As the country develops, with more buildings being built, and as the population grows, with more people demanding thermal comfort in the buildings they work and live in, the rate of electricity consumption for cooling purposes will continue to increase dramatically from year to year. This phenomenon requires the application of alternative energy options and thermal storage. Ground thermal storage is an example of thermal storage which can supply cooling and heating effects resulting in a significant reduction of electricity consumption. This paper discusses the potential of the implementation of ground thermal storage by using a ground heat exchanger (GHE) to supply passive cooling for any application. An analysis has been conducted based on an empirical equation from conduction heat transfer for depths of up to 30 m and thermal diffusivities from 0.04 to 0.1 m²/day. The main input parameters were obtained from a local weather station for three consecutive years. The result showed that a significant reduction occurs at a depth of 2.0 m and below, meaning that cooling can be supplied constantly throughout the year. The temperature amplitude is also attenuated relatively with depth, whereby amplitudes of less than 1 °C occur at a depth of more than 4 m with a thermal diffusivity of 0.04 m²/day. In addition, thermal diffusivity gives a significant increment in temperature amplitude and it is suggested to be maintained at a value of less than 0.06 m2/day. This result provides useful information to researchers and engineers in the field of underground installation of materials or systems such as gas pipelines, water supply and for underground cable transmittance.