Energy efficient windows
VELFAC composite aluminium / timber frames are designed to deliver maximum energy efficiency. Double glazed as standard (with triple glazing an option), a VELFAC window can achieve a U-value as low as 0.8W/m2K.
The space between glazing panes is filled with low conductivity gas, while the use of ‘WarmEdge’ – rather than aluminium – spacers between glass panes helps minimise heat loss further. Low emissivity coatings also actively reflect thermal heat back into the interior.
The VELFAC slim frame maximises solar gain and natural light – reducing dependency on artificial heating or lighting – and helps reduce U-values further, as glazing is usually more energy efficient than the frame.
Harnessing 'good energy' with VELFAC
What is good energy? When we talk about windows and energy there’s a lot more to consider than just U-values. A window is not like a brick wall, designed to keep the cold out and heat in. The latest energy-optimised window can actually contribute more energy to a building than is lost through the window.
When specifying windows for a low-energy building it’s important to consider:
- Window orientation in relation to the sun
- Requirements for sun screening and shading
- The glass to frame ratio
- Installation methods and thermal bridges
- The number of windows and total window area
- Air tightness
Further information can be found in the Good Energy brochure.
In simple terms, the U-value measures the amount of heat allowed to escape through a window (heat loss). When assessing a window’s ability to retain heat (insulation), the lower the U-value the better.