New patio doors and window condensation - on the outside!

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Recently had 2 patio doors and a new kitchen window fitted by a long established local window fitter. However, these new units "mist up" (or get condensation on them, whichever description is the right one?) on the outside on mornings like we have today i.e. cold and damp. This does not look right to me at all as all our existing windows don't do this (and the old doors that were replaced didn't do this either) but I'm being assured that this is "normal"

Clearly we're not really happy with either the condensation or response from the fitter.

So my questions are

1. Is this really "normal"
2. Is there an inherent issue with these doors/window
3. What course of action would you take from here considering the response from the fitter? (assuming that this is not normal)

Thanks
Steve
 
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Completely normal on high spec units, shows the glass is working effectivley, the sun should burn the dew off by mid morning, don't blame the fitter or the company they have supplied and fitted the very highest spec
 
Post a photo, do you definitely mean on the outside of the door ie exposed to the elements, rather than the inside of the outside pane ie in the gap?
 
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Firstly, apologies for my question being posted twice. I blame getting used to the keyboard on my new laptop :)

Secondly, thanks for the reassurance that this is normal and maybe even desirable as it indicates that a quality unit was fitted.

Wasn't trying to blame anyone at this stage, just wanted to know if normal, if not then maybe look for someone to blame :)

The condensation/mist/dew (delete as appropriate) is definitely on the face of the glass that is directly exposed to the elements. If I go outside I can run my finger through the moisture. The sun does indeed burn it all off by mid morning.

Thanks
Steve
 
This same question has been asked on here before so no need to apologise although i understand why you thought something was wrong.

It is caused by the outer pane of the glazing being colder than the glass that it replaced. With older style double glazing a larger proportion of heat was lost to the outside through the glass hence your old frames/glass didn't condensate outside. With modern low e glass products more of the heat is kept inside and the outer pane is not heated as much. Moisture condenses out of the air onto a cold surface that is said to be below the dew point. The dew point varies with the air temperature and the amount of moisture it contains.

In spring and autumn in particular the glass temperature can fall to a low level during the night and the dew point can be comparatively high in these seasons. The glass is more often likely to be below the dew point in these conditions and the moisture condenses onto the surface.
 
As crank said.

Basically it shows that very little heat is escaping to the outer pane of glass. It is a good thing in terms of keeping your heat in but also a bit of an annoyance when you cant see out in the morning.

This is becoming the norm now as the government are forcing us to fit more and more efficient windows. Feel free to write a letter of complaint to your MP :LOL:

It will hopefully only happen for a few weeks of the year when the conditions are right (or wrong you may say).

The below is from one of the major glass manufacturers websites:
http://www.pilkington.com/europe/uk...ked+questions/householders+faqs+-+general.htm

From time to time, we receive enquiries about the appearance of external condensation on glass. This phenomenon is a natural occurrence and not a fault in the glass or window
Moisture condenses out of the air onto a cold surface that is said to be below the dew point. The dew point varies with the air temperature and the amount of moisture it contains. Particularly in spring and autumn, the glass temperature can fall to a low level during the night and the dew point can be comparatively high in these seasons. The glass temperature can be below the dew point under these conditions and moisture can condense onto the surface.

In order to save energy, maintain a comfortable internal environment and satisfy building regulations requirements, the windows we fit in our homes 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 condensation on the external surface. In northern European countries, where levels of thermal insulation are higher than in the UK, the phenomenon is understood and accepted.

There is not much that can be done to avoid the risk of condensation to the outside. In many cases the condensation does not last long. A little heat from the sun warms the outer glass enough to evaporate the moisture and a gentle breeze or wind will help.

Those people who have fitted Pilkington Activ™ self-cleaning glass may also notice that they get fewer occurrences. Pilkington Activ™ is as prone to condensation as any other glass, but the properties of this product means it does not allow the water to form beads on the surface of the glass. So you tend not see the effect to the same degree.

You may notice that not all of the panes are affected by early morning condensation, even in the same window. Subtle differences in orientation and the position of objects outside the window can change the surface temperature of the glass to the point that one pane suffers and another does not. Any object such as a canopy or tree blocking off the window to a clear night sky will also reduce the effect.

A plus point is the knowledge that your windows are keeping the heat in as they are designed to do, proving that you have a superior insulating glass product.
 

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