windows misting on the outside

grumbler

bob_a_builder said:

I noticed this on ours the other day too , but for a different reason

The window on the right is a new unit ( 1 year old) , the one on the left is original ( 12 years old) 
So the old one is misting on outside, the new one not 
Which given  answers above (and logic) is a bit worrying about heat retention thru this unit 

But there is no internal misting so it must still be a sealed unit 

And we have the same case on another window where one side was replaced and other original - and the new ( 1 year old ) one is not misted on outside

It's possible that the older unuts are of better quality, e.g. filled with some inert gas. Is it argon, that they use?

bob_a_builder

I did pay extra to have the much larger patio doors 'Argon' filled ( who knows if they did ?) originally but not the smaller windows

Eldi_Dos

bob_a_builder said:

I did pay extra to have the much larger patio doors 'Argon' filled ( who knows if they did ?) originally but not the smaller windows

Could you check the misting on outside and compare to adjacent windows.

bob_a_builder

Good point !
Patio door side of house gets early sun so rarely see misting that side of house unless really 

'Argon' thing was just my cynical side coming out rather than anything specific 

chris_n

Looking at the colour of the sky they have different coatings. If the old unit has warm edge spacers and low E glass and the new doesn't it could lead to this issue. 

Chickereeeee

bob_a_builder said:

Defo on the outside - you can see mark (upside down V)  I made on outside of window ( on opposite house roof) 
No curtains, horizontal blinds but not used as room not in use at moment 
Sun not got round to that side at all yet

The bar separating the glass is different new to old - old one seems to have a insulator break between inner and outer side

Have a IR thermometer, will see what differences I can read on inside when its a bit colder outside

Are you sure the LH one is not triple glazed?

bob_a_builder

"Are you sure the LH one is not triple glazed?" 

yes 100% sure its not 

bob_a_builder

chris_n said:

Looking at the colour of the sky they have different coatings. If the old unit has warm edge spacers and low E glass and the new doesn't it could lead to this issue. 

Looking back at the original window order in 2007 - it refers to "Std K Glass"  ?

Bendy_House

bob_a_builder said:

Defo on the outside - you can see mark (upside down V)  I made on outside of window ( on opposite house roof) 
No curtains, horizontal blinds but not used as room not in use at moment 
Sun not got round to that side at all yet

The bar separating the glass is different new to old - old one seems to have a insulator break between inner and outer side

Have a IR thermometer, will see what differences I can read on inside when its a bit colder outside

It'll also be interesting to try the IR therm on the outside, see if there's different levels of heat escaping each pane from the inside.

Are you able to tell if the glass sheet thicknesses are the same or different? Ditto the central gap?

I've no idea how "Std K Glass"* compares with newer 'standard' stuff - I'd imagine there could only have been improvements, if anything? But the 'K' was apparently a coating which helped reflect heat back in to the room. Interesting...

* Presumably 'Pilkington K'

jonnydeppiwish!

Is it possible that the new window has a treatment on it that just repels the dew?