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New double glazing cold to touch and condensation covered

Postby DaveR83 » Thu Oct 21, 2021 10:51 pm

Hi all. Really need someone to explain the science behind this because what my window fitter is telling me doesn’t make sense.

I have existing double glazing in my flat and noticed in Jan that I was getting condensation inside 3 of the panels. All the other windows were fine and don’t get much condensation on their main indoor surface either.

It turned out the 3 windows in question had been packed a bit too tightly so had issues with the seals leaking.

Anyway, window guy fits 3 new panels, happy days. However, I come in the next morning and the 3 new panels are top to bottom in condensation, loads of it! I have to wipe it all off every morning so that it doesn’t start dripping onto the window ledge and cause black mould etc.

I also check the windows at other times of the day, when there’s no condensation, and they 3 new panels are noticeably colder to the touch.

Now I’m no scientist but I thought a new well insulated window panel would be warmer to the touch on the inside based on the assumption that the vacuum in the middle is separating the cold air outside from the warm air inside?

He tells me that it’s actually doing it’s job well and that because the seals are better the water in the air settles more on those windows.

But hang on, they look as bad in the mornings now as the single pain windows in my old gaff. Surely if they’re cold to the touch compared to the others that means whatever is in the middle of the two panes of glass is not doing its job properly?

Also, you telling me if I wanted brand new double glazing throughout I’d have to put up with top to bottom in condensation on every window all throughout the winter? That doesn’t make sense!

I’ve ready so many altering views on this and it’s very confusing. All I know is I got one problem fixed only to now have another.

Well informed answers highly welcome.

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Postby stoneyboy » Fri Oct 22, 2021 9:24 pm

Hi daver33,
You will need to do some investigation- are the new units the same spec as the old ones. Eg are they the same thickness? Is the inner pane solar reflective - planitherm? Has the same thickness glass been used on inner and outer panes. Your supplier may have left spec labels in case you need to make a guarantee claim, so have a look for these.
Regards S
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Postby GlazingInsider » Sat Nov 13, 2021 2:56 pm

Hi daver33,

What heating source do you have in the room for the sealed units in question? The inner pane of the units warm up if they are in a heated room and then their job is to keep the heat in. If however there is no heating source the overall room will have a lower temperature and the glass pane will also be colder, causing water vapour to condense on them. Condensation is also a home problem, with that amount of condensation it would seem you have an excess of water vapour in your home which can be caused by things like steam from the bathroom or drying clothes indoors.
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