Use of Underground Constructions Enhanced with Evaporative Cooling to Improve Indoor Built Environment in Hot Climate

Abstract

Underground constructions (UGCs) have been used globally to accommodate a wide range of building usage, such as offices and shopping malls. Most of these constructions suffer from a lack of natural ventilation as well as daylight, as they are completely built under the surface of the earth. This has caused many issues related to discomfort, impacting the activity and the productivity of users. This study aimed to analyse the effect of the use of UGCs in hot regions, enhanced by partly elevated external walls which reach aboveground to ensure natural ventilation and daylight, with relatively small amounts of glazing to minimise the influence of solar heat gain. The study used a real built underground room with field measurements for indoor temperature and relative humidity. Moreover, the study used the computer tool EDSL TAS to simulate the performance of the model throughout the year after a field validation. It was concluded that the use of UGCs in hot climates should be encouraged as natural ventilation and daylight can decrease temperatures by 3 °C in summer, and the utilisation of evaporative cooling can cool the indoor environment by nearly 12 °C. Furthermore, heat transfer was highly affected by the external environment. It was found that the amount of heat transfer doubled in comparison between under and aboveground constructions. The use of small windows for ventilation caused high humidity, even in hot regions, during summer.

Pilot Study on Underground Air Temperature for Interior Thermal Comfort of Building in Malaysia

“…However, a simulation study on the soil vapour intrusion in a basement shows that it is unpredictable to evaluate, thus the health risks due to poor indoor air quality in a basement requires higher consideration [20]. It was found that the usage of underground construction in hot climates should be encouraged since natural ventilation and daylight can reduce summer temperatures by 3 degrees Celsius and evaporative cooling can cool the indoor environment by roughly 12 degrees Celsius [21]. Although, there is a finding revealed that the connection between energy consumption and U-value of envelopes for underground constructions differs from that for above-ground buildings: enhancing thermal performance of outside walls does not reduce energy consumption and may even increase energy costs [22].…”

Indoor Thermal and Ventilation Indicator on University Students’ Overall Comfort

“…Among these four aspects, TC and IAQ are commonly suggested for priority consideration to avoid healthrelated symptoms, absenteeism, and loss of concentration [10,11]. Thus, to guarantee the health and efficiency of occupants, a better indoor environment with suitable TC and IAQ is suggested [12], and many studies have focused on particular methods to achieve better IEQ, such as the use of windcatchers [13][14][15].…”