Analysis of the Life Cycle Energy Impacts of Vacuum Insulated Glass in Manufacturing and Sustainable Buildings

Abstract

Building energy efficiency targets have sharpened focus on the embodied costs of high-performance products. Vacuum Insulated Glass (VIG) offers a centre-of-glass U-value in the range 0.4–1.2 W/m²K — well below that of conventional Insulated Glazing Units (IGU) — but its manufacturing is more energy, and process, intensive. This paper presents a hybrid Life Cycle Assessment (hLCA) of VIG production across six manufacturing scenarios, combining process-level expenditure data, based on US manufacturing, with the GLORIA multi-regional input-output (MRIO) database. The hLCA base case — high-temperature solder glass edge sealing — yields a total embodied energy of 543.3 MJ/m² and GreenHouse Gas (GHG) emissions of 108.6 kg CO₂-eq/m², approximately 5.1 and 2.3 times the IGU reference values, respectively. Alternative sealing processes (and the respective materials), including ultrasonic soldering/welding, reduce these burdens by up to 37.5% in energy and 28% in GHG. An operational payback analysis across four US climate zones (ASHRAE 1A–5A) shows energy recovery in as little as 0.6 years and an Energy Return on Investment (EROI) of 7.6:1 to 47.1:1 over a 30-year service life. VIG recovers its manufacturing energy investment many times over, where the magnitude of that return depends directly on the sealing technology implemented in manufacturing.