Reducing the Cooling Loads of Buildings Using Shading Devices: A Case Study in Darwin

Abstract

It is estimated that almost 40% of the world’s energy is consumed by buildings’ heating, ventilation, and air conditioning systems. This consumption increases by 3% every year and will reach 70% by 2050 due to rapid urbanisation and population growth. In Darwin, building energy consumption is even higher and accounts for up to 55% due to the hot and humid weather conditions. Singapore has the same weather conditions but less energy consumption, with only 38% compared to Darwin. Solar radiation can be defined as electromagnetic radiation emitted by the Sun and the Darwin area receives a large amount of solar radiation; building energy consumption can be reduced hugely if this radiation is blocked effectively by analysing appropriate shading devices. This study investigated the influence of different types of shading devices on the cooling load of a town hall building located in Darwin, Australia, and proposed the optimal shading device. The results showed that the horizontal fins led to a 5% reduction in the cooling load of the building. In contrast, adding a variation to the device angles and length increased the savings to 8%. The results demonstrated that the overhangs were more efficient than the fins, contributing 9.2% energy savings, and the cooling reduction savings were increased to 15.5% with design and length variations.