All new windows installed today must comply with minimum standards of thermal insulation. To replace existing windows simply to meet modern standards would not be very cost effective, nor in itself particularly environmentally friendly (waste disposal/recycling, manufacturing processes). However, upgrading the glazing may offer a sensible option, especially if some of your glazed units are already failing.
WHAT IS THE DIFFERENCE?
A standard ‘old fashioned’ glazed unit, will typically have a ‘U value’ of around 2.8. These will consist of 2 leaves of standard 4mm float (or toughened safety) glass separated by an aluminium ‘spacer bar’ creating an air gap of anything from 6 – 20mm. Although 6 – 10 would be quite uncommon still in use today, we are thus assuming the gap to be 12 – 20mm.
AN ‘A RATED UNIT Consists of a specially coated glass*, bonded to a second leaf using thermally efficient ‘super-spacer’ , then filled with inert Argon gas.
These units have a ‘U value of 1.1-1.2, LESS THAN HALF that of a standard unit.
WILL MY HOUSE FEEL WARMER IN WINTER?
We cannot answer that specifically; as every property is different, and windows form only part the overall ‘insulating envelope’. However it would be entirely reasonable to believe an overall improvement in insulation, will bring benefits in reduced heating cost, in much the same way as installing cavity wall insulation.
WILL MY WINDOWS LOOK DIFFERENT?
Essentially, NO. A slight difference in the light transmission in itself would not be noticeable, but if you were to replace one glazed unit (because of damage for example) adjacent to one not replaced, you may notice the ‘A’ grade unit appearing very slightly tinted. We would therefore recommend replacing all units in one window together. (Also to gain maximum benefit).
For more details, call 0800 163197, or ‘Request a Quotation’