External condensation on highly efficient Upvc Windows is a natural phenomenon and actually an indication the window is performing as intended.
Even the Gardinia showroom is not immune to this phenomenon, sometimes when we arrive early on a morning our fancy new windows in the showroom will have some external condensation:
So why does this happen?
External condensation on UPVC windows is a natural phenomenon. In order to save energy, maintain a comfortable internal environment and satisfy building regulations requirements, the windows Gardinia fit in customers homes (and our showroom in this instance) are much more thermally efficient than in the past.
With single glazing and older style double glazing, a large proportion of heat was lost to the outside through the glass. With modern low emissivity glass, more of the heat is kept inside and the outer pane is not heated as much.
The more thermally insulating the glass is, the lower the outer pane temperature is likely to be and the greater the risk of external condensation developing.
With that in mind if external condensation didn’t occur on your old windows, that is proof the new windows are performing significantly better than the old windows.
Using snow as an example if snow has settles on one house roof and not the roof of the house next door, the roof with snow on is actually performing significantly better, as little heat is escaping though the roof to melt the snow. You can make an educated guess the heating bill will probably be a lot lower for the house with snow on the roof, compared to the house without snow.
So what can i do about External Condensation?
Not much can be done to prevent external condensation, however the good news is it never usually lasts for long. A little heat from the sun or often a gentle breeze is enough to help evaporate the moisture.
I actually failed the first time in taking a photo of our showroom for this blog post, by the time I went back out the office 20 minutes later the vast majority of external condensation had already cleared up. I’ve since had to wait several weeks for this to occur again and take a photo!
Hopefully this will re assure you external condensation is a naturally occurring phenomenon and never usually lasts too long when it does happen to occur.
More technical information can be read about external condensation on the Saint Gobain Glass Website and on the Pilkington Glass Technical FAQ.
