Simulating the Individual and Combined Utilization of Cool Paints and Phase Change Materials for Enhancing Energy Efficiency in High-Rise Office Buildings

This paper assesses the separate and simultaneous effects of utilizing cool paints (CPs) and phase change materials (PCMs) in the building envelope of high-rise office buildings on energy demand. Dynamic building energy simulations are used to investigate these impacts. CPs are known to scatter solar radiation, while PCMs are utilized for thermal energy storage in the building envelope. The effects of three CPs with constant thickness and place of application and three PCMs with varying thicknesses on the inner and outer layers of external walls are investigated, resulting in a total of three and twelve conditions for CPs and PCMs, respectively. Additionally, the study considers 36 modes of the combined use of CPs and PCMs. The study envisages that applying a combination of white CP with ATP23 PCM in the inner layer of external walls reduces 10.11 kW·hr/m²·year energy demand in the building (6.49% and 1.29% decrease in gas and electricity demand, respectively). While CPs are most effective in reducing energy demand during hot seasons, PCMs can provide benefits year-round. The economic analysis elucidates that the implementation of white CP yields a payback period of 3 years and an internal rate of return of 55% in the second scenario.