Typically, an IGU consists of two or more panes of glass that are hermetically sealed around their edges. The space between these panes is filled with air or an inert gas, such as argon or krypton, which has a lower thermal conductivity than air. This gas-filled cavity reduces heat transfer between the indoors and outdoors, significantly enhancing energy efficiency. Moreover, the external and internal surfaces of the glass may be treated with low-emissivity (Low-E) coatings. These coatings reflect infrared energy, further improving the thermal performance by keeping heat inside during the winter months and blocking it during the summer.
