Condensation Exterior of windows

I have replaced all the windows in our house with replacement vinyl double pane,low E windows and in two rooms have the following major problem. The exterior of the fixed pane windows become so fogged up with condensation you can not see through them at all,however the sliders remain nice and clear. The Contractor and the window company tell us this is normal. Even though all other windows in the house are fine. I hope someone on the forum can help us. singed sad owner LFJR

 

So you can go outside your house and wipe the condensation with a finger? How strange! When does this occur? morning? evening? night? Does the fog cover the entire window surface, or just part of it? Are the windows in the sun or shade? Is your dryer vent or heater exhaust nearby?

 

LFJR, exterior condensation on dual pane LowE units is a normal occurance and not a cause for alarm at all.
This phenomena is related to very specific weather conditions and can be commonly seen on some windows in a home, but not all, often depending on the orientation of the house and the particular window involved.
Because of the energy efficiency improvement in the newer windows, and especially because of the lowE coating, the indoor heat is reflected back into the house which allows the exterior of the exterior lite to be below the dew point and thus condensation forms.
This phenomena is dependent on having a clear night and the windows have to have an unobstructed "view" of the sky as well.
I can get a bit more detailed, but bottom line is that condensation on the exterior of a dual pane, LowE unit simply means that you have a high performance unit that is performing normally.

 

Thanks Doc for your fancy script... But once again! (x slider, o fixed pane, x slider ) same window!.....xox... Sliders x fine---fixed o window exterior condensate so bad you can not see a flashlight through the outside or the inside. However sliders x on each end ,same window just fine. Anyone else care to respond... ? Stick with your trade !!! LFJR

 

Ok. yes sponge!... no finger!...,YES at night,! no heater vent, no dryer this is my Master Bedroom window 5'0"x 8'0" sliders each end are great,,, center fixed pane exterior so fogged I wish I had my old window back.... I'm thinking MFG defect.... 60 to 40 degrees so far..at night NOR CA... Not that cold...Again not the sliders on each end, only the center pane and yes the entire pane is affected... thanks for the help Guys. These are Somerton 2 in the entire home all are fine. Last thread next stop LLP. :wall

 

If I understand correctly, it fogs up at night, and is then foggy right away in the morning? And the entire pane is affected. It would be notable if the condensation was less on the side and top edges of the glass, but you did not mention this.

In your XOX configuration, is the piece of glass in the center fixed lite the same size as the ones that operate? When you look at the spacer bar, between your IGU's is it the same type of spacer bar as the other windows? And is the IG the same thickness as the others?

Oberon's reply is spot on. This *IS* his trade. There has got to be some reason your windows are doing this, and what it comes down to is: the IGU's that are fogging up have a BETTER u-rating than your smaller ones. (heat loss from the house is not warming the outside of the glass sufficiently to keep condensation off the glass when it reaches the dew point). I suspect this will be due to the size of the glass, and am guessing that your center fixed windows are square, and almost twice as big as the ones that operate. It also could be that your fixed windows have IGU's that are thicker- also an indication of a better u-factor.

 

Thank you all for the great feed back!!!!!This site is awsome. Faced with all the info from your threads the window mfg has agreed to replace the panes in question. Thanks guys for all the help and sorry for my short fuse. Keep up the good work and THANKS. LFJR.