Combination of Wall Insulation and PCMs in External Walls of Typical Residential Buildings in the UK and Their Impact on Building Energy Consumption

With growing concerns over global warming and the significant contribution of buildings to energy consumption, reducing energy demand in buildings has become crucial. This study addresses this issue by investigating the integration of phase-change materials (PCMs) with wall insulation on the inside surface of building exterior walls as a strategy to reduce energy consumption. The methodology involved conducting simulations using OpenStudio and EnergyPlus software to assess the thermal performance and energy savings of this approach. The parameters evaluated include energy consumption reduction, material selection and thickness, cost savings, and payback period. The results show that combining a 100 mm Celotex TB4000 Insulation Board with a 1 cm PCM RT24HC layer can reduce energy consumption by 65.4%, save approximately GBP 1645.67 annually, and achieve a payback period of 13 years. Additionally, the selection of the PCM phase-change temperature, thickness, insulation layer thickness, and indoor temperature settings are crucial to optimizing the combined effect. Based on these results, it is recommended that designers and practitioners consider these factors when conducting pre-retrofit simulations to ensure that PCM-enhanced insulation operates within its optimal temperature range.