How many layers are present in double-walled glazing?

Double-walled glazing, often used in greenhouses and other structures requiring temperature control, consists of two layers of glass or plastic that create an insulating air gap between them. This design enhances thermal efficiency by reducing heat loss and minimizing the impact of external temperatures on the interior environment.

The key benefit of having two layers is that they form an air space that acts as an insulator, which significantly improves the energy efficiency of the structure. This is particularly important in floriculture settings, where maintaining specific temperature and humidity levels is critical for plant health and productivity.

The other choices suggest either fewer than two layers or an excessive number of layers. A single layer would not provide the insulation properties that define double-walled glazing, and more than two layers would refer to thicker glazing systems that are not typically classified as double-walled. Thus, two layers are essential for creating the insulating effect that is characteristic of double-walled systems.