Investigating the thermal performance of fibre reinforced polymer wall panel system in Waikato, New Zealand

• First empirical investigation of FRP wall panel system in residential building • Indoor temperature remained within 18–24°C for 67.6% without mechanical cooling • The 26 mm airgap mitigates heat transfer variability against outdoor fluctuations • FRP as a climate-resilient alternative to conventional construction • Material-specific thermal resistance and airflow dynamics for sustainable design The New Zealand building sector has long faced challenges such as inadequate insulation, indoor overheating and unhealthy living conditions, which are exacerbated by climate change, emphasising the need for innovative and climate-resilient material. In this study, the thermal performance of a novel fibre-reinforced polymer (FRP) wall panel system, including insulation in the cavity and an air gap, is experimentally examined in a case study building using field monitoring during peak summer conditions. Specifically, the impact of varying outdoor conditions and airflow on the indoor temperature, heat transfer through the walls, and air gap temperature were studied. The result showed that the indoor temperature of FRP panel system remained within the comfort range of 18-24°C for 67.6% of the observation period without mechanical cooling, outperforming conventional construction by about 10% in mitigating overheating. The air gap present in the system minimized temperature fluctuations by reducing heat transfer through wall and airflow (0.08 - 0.12 m/s) stabilised indoor temperature by reducing heat gain/loss variability. Furthermore, numerical simulation results aligned with experimental data within a 10% accuracy margin. This study provides the first empirical evidence of FRP’s viability as an alternative solution in New Zealand’s climate, highlighting material-specific thermal resistance and airflow dynamics as critical design priorities for energy-efficient, climate-resilient housing to address escalating climate challenges.