Glass Canada • June 2025 • The Engineer

In the early 1990s, Shuji Nakamura of Nichia Corporation invented the blue light-emitting diode, enabling the creation of energy-efficient white light and full-colour displays. LEDs consume up to 80 percent less energy than traditional incandescent and halogen bulbs. Since electric lights account for around 25 percent of the world’s electricity consumption, Nakamura’s invention has had a profound environmental impact.

Over the last few decades, the fenestration industry has seen such technological advancements as thermally broken frames, polymer-based reinforcements, multiple panes, noble gas fills and low-emissivity coatings. Yet, while these developments have made meaningful progress, they represent incremental changes. Many believe the industry has reached a technological plateau. What is needed now is a revolutionary breakthrough – something akin to the impact of the blue LED.

One technology that promises to be that breakthrough is vacuum insulating glass. Over the past few years, VIG has transitioned from an industry buzzword to a fast-approaching reality. It is increasingly featured in seminars, conferences and industry podcasts, signaling growing momentum and widespread interest.

For those unfamiliar, VIG is a high-performance glazing solution that drastically reduces heat transfer by utilizing a vacuum between two glass panes. Unlike conventional double-glazed windows, which rely on air or argon gas as insulating layers, VIG nearly eliminates thermal conductivity. With no air molecules between the panes, heat transfer through conduction and convection is drastically minimized, resulting in significant energy savings.

The most significant advantage of vacuum insulating glass is its superior thermal performance. A single VIG pane, usually between eight and 12 millimeters thick, delivers nearly three times better insulation than a conventional dual-pane IGU, but in a slimmer, lighter form. VIG can also be integrated into hybrid units, combining a VIG pane with a standard pane to create a “hybrid vacuum IGU.” These systems significantly outperform triple-pane IGUs and, in many cases, rival the insulating values of insulated walls – an impressive feat for a transparent material.

Given its advantages, why hasn’t VIG already taken over the market? The quick answer is cost, largely driven by the technical and manufacturing challenges involved.

First, the glass must be extraordinarily flat – particularly difficult when producing tempered glass, which is commonly used for its strength and safety. Even minor warping can compromise the vacuum seal.

Second, achieving a durable hermetic seal around the perimeter has been a significant technical challenge. If the seal is breached, the vacuum is lost and the unit’s insulation performance collapses. Visually, failed VIG units often show support pillars that have fallen out of alignment and pooled at the bottom of the pane.

Lastly, manufacturing VIG requires specialized equipment and significant capital investment. Until recently, these factors made VIG production prohibitively expensive. However, with increasing demand and advances in production techniques, the costs are starting to decrease. Today, the lifetime energy savings provided by VIG make the investment more justifiable, and several manufacturers are scaling up operations to meet growing market demand.

Vacuum insulating glass represents a major leap forward for the fenestration industry. Its exceptional thermal and acoustic insulation, combined with a slimmer profile and environmental benefits, make it an ideal choice for energy-efficient, modern buildings. While challenges such as cost and durability remain, the future of VIG looks bright. As production scales and prices fall, VIG has the potential to become a standard component in sustainable building practices, much like the blue LED revolutionized lighting a generation ago.