Whether
you are a domestic customer or trade customer you may have heard the term 'A
Rated Glass' being used. There is however no such thing.
This
term is becoming frequently used in the uPVC industry to describe a
glass specification that will allow a window to achieve an
'A' rating. The actual glass specification they are referring to is:-
4mm
Clear Float - 20mm Argon Gas Filled Spacer (90%) with Swiss V (or similar)
Thermal Spacer Bar - 4mm Low-e (softcoat). This glass make-up achieves a centre
pane U-value of 1.2 W/m2K.
In the
majority of uPVC window systems this glass allows the window to achieve an Window
Energy Rating of A, hence why it is being increasingly referred to as 'A Rated
Glass'. Unfortunately, it does not always result in an overall A rating when
Glazed into window systems and it is becoming more and more confusing for the
end customer and trade alike.
The
Window Energy Rating (WER) system applies only to windows, it also only applies
to the window as a whole. Individual components cannot themselves have a window
energy rating, i.e. the glass or frames.
This so called 'A Rated' glass specification we use as standard for the majority of our products. Using
this so called ‘A’ Rated glass in one of our aluminium Smarts 47
windows (for example), achieves an overall 'C' Rating. Although this is still
fully compliant with current building regulations, it may not be what the
customer is expecting.
Find out
more about WER’s here: http://www.duration.co.uk/Window-Energy-Ratings.asp
