Double Glazing...problem Or Not?

[dunnitall]

Re double glazing....any ideas please? Newly installed and the one window which opens at half way point is actually getting misting and condensation on the OUTSIDE of the window when I put the heating on. The radiator is not near the window. All the other windows do not have this problem.

I also notice when heating isn't on..evenings or overnight ....it's so much colder in that room than when we had old window in there. As I say all other windows...no condensation on the outside. My DD says one window at hers does the same so it's 'normal'. I can't see how it is when the other doubled glazed ones do not have the problem. Can anyone throw any light on this please as I don't think it's right and needs to be rectified.

Many thanks for any help you can give.

[TonyV]

you should not get any misting inside a double glazed unit. If you do unit is faulty and needs replacing if its still under guarantee.

[dunnitall]

Thanks Tony it's what I thought. DD sent me link to read that it is normal!!! But I can't believe that especially when all the other windows aren't the same. Luckily still under guarantee so will do the necessary.

[Gizmonster]

Assuming it's on the outside and not actually in between the panes, it's nothing to worry about:

https://www.cheamwindows.co.uk/what-causes-external-condensation-on-double-glazed-windows/

[TonyV]

Dunitall are you just getting condensation outside and inside glass but not actually in the cavity between glass?

[dunnitall]

Tony, it's definitely on the outside, my other half went out and actually rubbed the mist/condensation off the outside. It's NOT in between the two panes definitely. As I say my DD says it happens to one of hers on the outside and sent me this link to tell me it's normal, but I am not convinced.

http://www.clearviewhome.co.uk/blog/why-do-my-new-energy-efficient-windows-mist-up-or-have-condensation-outside/2016/10/

I cannot see why as all the other windows do not have this problem....even one in the kitchen with the rad under the window. So surely it's not normal?

[alavahalf]

A couple of years ago we built a conservatory at the rear of our house .. all the glazing units are gas filled with Argon. We were amazed at the way the building retained the heat, so amazed that I decided to replace all the old double glazed units in the house .. with the new gas filled versions.
The thermal efficiency is far superior to the older style double glazed unit and we now have condensation ... but only on the outside where it should be !

[TonyV]

dunnitall just shows your double glazing is working well, keeping heat inside, perfectly normal to have condensation on outside, wheres it cooler overnight and in the morning. Theres lots of over factors to take in to account as well. If you want to now google dewpoint.

[snags]

But the OP says this only happens on one window... meaning all the other windows aren't working as they should?

[TonyV]

looked at you link in first sentence was dew point, as I mentioned, not complicated, happens every day.

[Gizmonster]

I'm a window cleaner and I come across this quite often - usually first thing in the morning.
Like I said in my last post, it's quite normal :)

[KARL]

Condensation only occurs on surfaces colder than the ambient temperature to the point where the moisture within air in contact with a surface condenses and settles on that surface. The only way to ensure condensation does not occur is to ensure the surface is sufficiently warm. Normally, the only way the temperature of the outside surface of a windowpane is raised is by sufficient warmth from the inside of the house passing to the outside - that is called heat loss. What you describe is your double glazed units being thermally efficient and keeping the heat inside your house. Most people would be pleased with that but by all means ask the installer to change the units to something less efficient so you don't have condensation forming on the outside - although I can't see the problem.

[TonyV]

snags depends on which facing that particularly is, i.e north, south, our anything in between, how much wind it gets, ect lots of factors effect dew point

[dunnitall]

Thanks for all your comments. It's not a problem as such but it's never happened before. The two upstairs windows which are new too, there's no condensation on the outside of them ....all facing the same direction so I was wondering if there was a problem with the one downstairs. To be honest, the installers have made a hash of one of the back windows and have got to come back to sort that one and do other bits and pieces.

So whilst the condensation outside isn't bothering us too much I just wanted to check if they have botched this particular window too. Many thanks for commenting, much appreciated.