Latest news from Clearview Bi-Folding Doors Ltd

Making Your Choice of Glass More Transparent

16 December 2021

Did you know, the average home loses up to 25% of its heat through the windows – with 90% of this heat loss being through the glass itself? With this in mind, it’s amazing how many people overlook the importance of glazing when they are looking to upgrade their doors or windows.

So, how does glazing work and how is thermal insulation measured?
If you have been comparing doors and window systems, you will probably be familiar with the ‘U value’ rating. U-values are expressed as W/m2K, which refers to the amount of energy that passes through 1 metre squared of a material for each degree of temperature difference from one side to the other. So in short, this is the amount of heat that passes through glass when it’s colder outside than it is on the inside. So as you would imagine, the lower the number, the better.

Modern Low-e glass has far lower U-values than traditional glazing – this is thanks to a near-invisible coating that is usually applied to the inner pane of a double glazed unit. A low-e coating works by reflecting any warmth back inside whilst still letting through heat directly from the sun. This process is known as ‘passive solar gain’ essentially allowing buildings to be heated by natural sunlight – a huge benefit during the colder months of the year.

In general, modern thermal insulation is provided by double-glazed aluminium windows or doors containing one pane of low-e glass, with an inert gas such as argon (which offers a far lower thermal conductivity than air), within the cavity. It is also possible to achieve greater levels of thermal insulation by specifying a low-e coating on both surfaces. It’s an increasingly popular alternative to triple glazing as these advanced glazed units can achieve a U-value as low as 0.9W/m2K!

Factors specific to your project will affect our recommendation for glass – factors such as the location, aspect, size and product. If you have any questions regarding your choice of glass, then get in touch with our team today.