Internal or external thermal superinsulation towards low/zero carbon buildings? A critical report

Abstract

The effort to create low-carbon societies is now more than just a need for a sustainable world. According to the sectoral energy analyses carried out to reduce world energy consumption figures and greenhouse gas emissions, buildings are one of the most striking potential measures within the net zero target of the International Energy Agency (IEA) by 2050. Low/zero carbon standards are developed in this regard, which basically propose low-emission design and operational performance for buildings. Rather than using conventional insulation materials and techniques, drastic measures like thermal superinsulation are required to meet these standards in buildings. Among thermal superinsulation materials, aerogel blankets (ABs) and vacuum insulation panels (VIPs) attract attention day after day owing to their very low thermal conductivity ranges. Despite the slim, lightweight, and highly thermally resistive features of building envelopes retrofitted with ABs and VIPs, there are still some challenges, such as thermal bridges, hot and cold spots, durability, and especially cost issues. The aforesaid challenges usually take place when a wrong decision is made to internal or external insulation. There are still numerous discrepancies in the pros and cons of internal and external thermal superinsulation retrofit. Therefore, this short communication deals with the said discussion through the in-situ performance findings of retrofitted buildings.