Evaluation of Thermal Performance of Innovative Insulation Materials for Energy-Efficient Buildings in Cold Climates

This study investigates the thermal performance of four innovative insulation materials phase change materials (PCM), aerogel, vacuum insulated panels (VIP), and autoclaved aerated concrete (AAC)for cold-climate buildings in Varzaqan, Iran. Using 24 years of hourly climate data, five wall configurations (uninsulated reference, PCM, aerogel, VIP, and AAC) were simulated in EnergyPlus, with PCM behavior modeled via an enthalpy-temperature phase change routine. Key indicators included annual heating energy demand, wall surface temperature stability, time lag, and comfort hours. Results show that VIP achieved the greatest reduction in annual heating demand (36.6%), followed by aerogel (29.5%), AAC (24.1%), and PCM (21.4%). PCM and AAC provided substantial thermal inertia, delaying heat transfer by150-180 min and90-120 min, respectively, thereby enhancing night-time comfort. In contrast, VIP and aerogel maintained nearly constant surface temperatures (fluctuations <3ºC). Hybrid configurations offered the most favorable outcomes: a VIP+PCM wall reduced annual demand by 40.3% and achieved∼6510 comfort hours (74% of the year). Passive solar gains, when integrated into the analysis, improved PCM effectiveness by ∼12% in sunny winter days, while AAC showed moderate benefit and VIP remained largely unaffected. Sensitivity analysis highlighted VIP’s vulnerability to vacuum loss ∼12% performance degradation and AAC’s dependence on moisture, whereas aerogel and PCM proved more robust. Overall, the findings underscore the complementarity of ultra-low conductivity materials (VIP, aerogel) and high thermal mass/storage materials (PCM,AAC). While economic and practical barriers remain, hybrid approaches represent a promising pathway to significantly reducing heating energy demand and improving thermal comfort in cold climates.