Implementing Cool Roof and Bio-PCM in Portable Cabins to Create Low-Energy Buildings Suitable for Different Climates

The building sector's energy consumption has significantly increased due to climate change, emphasizing the need to develop sustainable low-energy buildings using experimental and computational tools. As a joint project between Kuwait and Australia, two portable cabins with internal sizes of 2 m x 2 m x 2.80 m, made from 75 mm thick sandwich panels and metal frames, were built in Kuwait to investigate their thermal and power consumption characteristics under various energy-saving techniques and different climates. This is the first attempt to analyze the energy-saving aspects of portable cabins made from sandwich panels for future sustainable cities. Each cabin has an indoor air-quality-sensing device and a novel power-monitoring system to measure their thermal and power consumption characteristics. First, shingles and novel finned metal cool roof (CR) techniques were experimentally investigated. Then, a new multi-zone SketchUp model of the portable cabins was created and simulated in TRNSYS. Next, the energy saving data of the portable cabins were investigated by adding PCM on the walls and the roof using built-in models of bio-phase change materials (Bio-PCMs) in TRNSYS. The annual energy performance index (EPI) as an important sustainability index was explored for determining heating/cooling/total demands of the portable cabins in the desert climate of Kuwait and in various climate regions of Australia. The findings reveal that both shingles and finned metal roofs contributed to higher power consumption. Meanwhile, the use of sustainable Bio-PCMs in Kuwait demonstrates a significant energy-saving potential of 30%, with variations ranging from 25% to over 45% across different climate regions in Australia.