Double glazing works in the same way as insulation. All of the work happens in the space between the two panes of glass that make up a double glazed window. This gap prevents head transfer because the space is too small to allow circulation.
As a result, two important things occur.
1. House stays warmer: Double glazing acts as insulation, helping reduce the passage of hot or cold air between the inside and the outside of the house. This means the inside air stays warmer or cooler for longer.
2. Less condensation: Double glazing helps prevent condensation from occurring inside the house when it is cold outside and warm inside. This is due to the reduction in airflow.
While double glazed windows do insulate from hot air temperatures, you must understand radiant heat is something completely different. If direct sunlight hits the window, its heat does pass through unobstructed. To help reduce this, special ultraviolet (UV) light blocking window coating or tinting is required – this works extremely well on double glazed windows. When deciding the best type of window for your house, take notice of whether your windows are exposed to direct sunlight.