Phase-change material (PCM) has the capability to enhance the indoor thermal comfort of a building as well as it has the potential to balance the heat and cool effect of a building material, especially when the material is exposed to severe environment. PCM works like batteries, by discharging the energy which it stores. When it has fully discharged or released its energy, there is a need to charge or store the energy back to the material until the storage capacity is full [1]. PCM is categorised according to its material specification and heat capacity. Very important before designing a PCM system is to understand that the energy supplied to/from the material is via latent process (fusion or vaporisation), which means the heat will be released and absorbed without or with minimum effect on the temperature change [2]. With enough amount of heat, a solid PCM will be fully melted when it reaches its melting point, and it is then ready to release the stored energy. In reverse, the melted PCM gradually turns to its original condition (solid) during solidifying process [3]. Up to this date, there are three types of phase-change materials: (1) organic PCM (2) inorganic PCM, and (3) eutectic PCM. The organic type was reported to be more chemically stable and it freezes with almost no supercooling, as compared to inorganic PCM. However, its low thermal conductivity causes it to have low latent heat capacity and requires more time to store and release the energy than the latter type. While inorganic PCM has proven to be more effective for active thermal energy supply system, organic PCM was reported to be better for passive heating or cooling strategy. This also applies in keeping good thermal comfort for indoor occupancy. Compared to the first two PCM types, eutectic PCM is the recent PCM technology that can accommodate both organic and inorganic traits, depending on the system design [4].
Research in analysing building performance and technologies has proven the PCM potential to improve the energy use in buildings, particularly when combating extreme weather conditions (summer and winter seasons) [5]. Not only that, the interest in researching the PCM application in making thermal energy system more efficient, such as integrating PCM with heat pump, has been increased quite recently. The system can be flexibly managed by storing thermal energy during high energy supply (low energy demand) and releasing the energy during high heating or cooling load demand. This can reduce the reliance on main grid energy supply to buildings and even more when adapting smart and sustainable approaches i.e., incorporating renewable sources [6]. The indirect implication of integrating PCM with thermal energy system will be achieving nearly net-zero carbon emission as well as mitigating the urban heat island (UHI) effect [7].
This project aims at researching a novel strategy to design an integrated PCM with thermal system in the scope of built environment, using the principle of thermodynamics [8]. Several relevant software which use computational fluid dynamics (CFD) and/or energy modelling analysis [9] are available within our department i.e., ANSYS, Revit, Arduino, Simulink and Matlab, but other simulation software i.e., EnergyPlus or IESVE can be proposed. This project will need the support data based on the local meteorological station and the experimental data collection of indoor and/or outdoor environment [10]. The available tools for the experiments are thermal humidity meter, anemometer, distance meter and infrared thermal meter.
Creative design solutions are mostly welcomed and shall be across disciplines i.e., built environment, renewable energy, thermodynamics, civil engineering, material science, etc. The PhD student must decide whether the system will be designed for active thermal energy supply or collector, or to be contributed in passive or active-passive thermal approaches, within the first three (3) months. Later, an intensive literature review will be required to complete within the first twelve (12) months, and it is encouraged that the literature review will be indeed prepared as a review article in a relevant high-impact journal. At the end of the final year, the student is expected to produce three (3) research outputs – one (1) review article and two (2) research articles. Enthusiastic, creative, active learner, self-motivated, and independent are the important traits to conduct this project.