Home Energy Efficiency and Energy Rating of Windows, By EPC Belfast

Energy-efficient glazing is the phrase used to characterize glazing made of an enclosed assembly of two or more glass panes. This encompasses double and triple-glazed door windows as well as related units.

Energy-efficient windows and doors comprise a frame material (wood, aluminium, PVC-U or composite) on which one or more sealed glass assemblies are mounted as per the design of the window or door.

Energy efficient glasses are rated by their potential to lower the quantity of heat passing through the panel, by the sun’s capacity to radiate through the glass panel and by air mobility through the panel.

The highest performance glazing is typically provided by low emissivity glass, which contains a special covering on the internal surface of a pane that enables light to pass through while reflecting heat back to the room.

Energy rating and u-values

Some window manufacturers signify their windows’ energy effectiveness with an energy rating varying from A++ to C, the most effective being A++, to facilitate buying. This assessment method was established by the British Fenestration Rating Council (BFRC) and takes the entire window into account.

Also, the entire window u-value is determined whenever this energy rating is given. U-value refers to the ease at which heat may flow through the unit. The u-value scale functions in the opposite direction of an energy rating since the higher the u-value, the easier heat will flow through the window and the less effective the window.

What is in between the glass panes of a sealed unit?

The air gap tends to reduce the amount of cold air that can enter your house. It achieves this by serving as an insulator and is thoroughly enclosed.

There is air or gas in the vacuum between the glass panes such as argon, krypton or xenon. This tends to minimize heat loss by the unit. As gas such as argon – which is of low conductivity – is used in this vacuum, the window is much more effective to retain heat in the building and to interfere with sonic waves from within or outside the building thereby minimising noise pollution.

The type of frame material used

The frame material used in energy-efficient windows and doors is also essential, just as with glass itself.

Numerous alternatives are available here:

PVC-U provides many advantages, including durability efficiency (usually 20 or more years) and can be recycled.

  • Wooden frames are compatible with the environment and are sometimes reserved for properties where original materials, such as in a protected area, are required.
  • Aluminium frames are a new, eco-friendly option since the materials are low in environmental impacts, they can be recycled and the sleek appearance of these frames is attractive.
  • Composite frames are constructed from wood and aluminium or plastic blends.

Dual glazed properties have a higher energy efficiency rating than single glazed properties. However, the frame of the glazing was found to have little influence on a building’s energy efficiency.

This article is provided by EPC Belfast. They are a group of Domestic Energy Assessors who provide Energy Performance Certificates (EPCs) in Belfast and surrounding areas.