Insulating glazing: light and energy

Natural light is at the origin of life, as well as the diversity of atmospheres and climatic changes.

Glazing is the interface between the outside world and the inside of a building.

Well-chosen, it determines the quality of the building, both architecturally and in terms of interior ambience.

Solar radiation is a source of energy that sometimes needs to be harnessed to reduce heating costs in winter, and to optimize thermal comfort by avoiding overheating in summer, while at the same time reducing heat loss.

Today's reinforced thermal insulation glazing combines good light transmission with high thermal performance. Energy losses are reduced in winter, and thermal comfort is increased. What's more, the surface temperature of the glass is higher, reducing the sensation of a "cold wall" and lowering the risk of condensation.

On the other hand, it's often necessary to limit the entry of solar energy, which can increase the "greenhouse effect", particularly for east, south and west-facing orientations.

Thermal discomfort in hot weather, whether air-conditioned or not, must be dealt with using low-solar factor glazing and, if necessary, additional protection such as blinds or sunshades.

Good sun protection, combined with appropriate ventilation, means that air-conditioning can be dispensed with in many cases.

After demonstrating the characteristics of glazing in relation to light and solar energy, this article goes on to show how these two characteristics can be influenced by tinting glass, depositing reflective coatings, or combining glazing with shading devices. We'll see how these measures affect thermal and visual comfort, and how they help control energy consumption.