The effect of cooled soil in earth-to-air-heat exchanger (EAHE) performance for hot humid climate (of Malaysia)

Abstract

This research is intended to investigate the effects of cooled soil on the performance of Earth- to- Air Heat Exchanger (EAHE) in buildings in Malaysia, which experiences hot and humid climate throughout the year. EAHE has been applied in many countries for building cooling, mostly in temperate or hot and arid climate where the diurnal temperature is large. However, minimal resources were found on the study of EAHE application to buildings in Malaysia. A field experiment on EAHE application in Malaysia was carried out in 2012 (Sanusi, 2012). A parametric study was done as part of the research and it concluded that among of many parameters in EAHE design, the soil temperature which surrounds the pipe was the most influential factor. Therefore, this research compares EAHE system buried underground under three soils surface conditions; bare soil with short grasses, shaded with recycle timber pallets and insulated using recycled tyre. This research method consists of data collection from soil measured in a test site for a month then simulated into Energy Plus software to obtain temperature difference, between inlet temperature (ambient) and outlet temperature (to building). This research found that soil insulated using recycled tyre at 1.0 m depth recorded the lowest amplitude temperature outlet among all with 26.708OC at minimum, while 27.172OC. Findings showed noticeable differences between inlet and outlet temperatures, thus showing data and software are reliable for this research. Further in- depth research were suggested on various types of soil and surface treatment and researcher wishes to generate interest among the community in adopting low- energy design and reduce solar heat gain, thus improving EAHE performances.