The panoramic glass façades of modern day high-rises and office buildings may be aesthetically pleasing, but they can come at a cost. The visible light they let in, accompanied by infrared light that can cause buildings’ temperatures to rise, can lead to increased air-conditioning use and higher levels of energy consumption, especially in hot, desert climates like the UAE.

The amount of energy needed to cool and ventilate all-glass buildings can make them extremely heavy users of resources, an expense that has both ecological and economic consequences. This is why glazing technologies – the specialized coatings that either reduce or increase the amount of heat and light that passes through glass, depending on the needs of the building – have a critical role to play in the future of glass manufacturing and sustainable urban development.
In fact, researchers estimate that optimized glazing can reduce a building’s cooling load upwards of 20%, which is significant in a country like the UAE, where air-conditioning accounts for up to 75% of peak-day electricity use in the summer months. But producing the necessary glass glazing is not easy, and thus, not cheap.

Conventional coatings achieve high selectivity – a measurement that indicates how effective a coating is at blocking heat but letting in sunlight – by stacking multiple layers, usually around five, of varying compositions and thicknesses on a glass pane. Most coatings today use expensive silver nanolayers sandwiched between other layers of various other materials.

The challenge thus is finding innovative ways to improve glazing technologies so that manufacturing costs remain low while also ensuring the natural-looking colorless appearance of glass is not sacrificed, as some heat-blocking coatings alter the color of the glass, giving it a less desirable brown or reddish appearance.