Double pane windows extremely hot
#1
Double pane windows extremely hot
Hi,
I have the typical builder Viking windows and sliding doors from about 1997. On the south-east facing units (including the large glass slider), the glass can get so hot you can't touch them and you can feel the heat radiating off them like an oven. The previous owner even put a reflective film on the windows but they put it on the inside.
I know that the primary purpose of double pane glass is to improve resistance to heat transfer but it seems to be much worse than single pane in terms of heat radiating from the glass itself.
I live in a primarily warm climate and I have done a lot of attic upgrades that almost eliminate the need for air conditioning but the windows are the major contributor now.
So my questions are-
1. Is it OK to put the reflective film on the inside glass of a double pane unit?
2. I'm considering replacing the slider with a new unit. The manufacturers have glass options that have hot climate low-e coatings. Do these make a significant difference over clear double pane?
Of course the best option is to shade the windows with trees or awnings etc. and I'm looking into that also.
Thanks
I have the typical builder Viking windows and sliding doors from about 1997. On the south-east facing units (including the large glass slider), the glass can get so hot you can't touch them and you can feel the heat radiating off them like an oven. The previous owner even put a reflective film on the windows but they put it on the inside.
I know that the primary purpose of double pane glass is to improve resistance to heat transfer but it seems to be much worse than single pane in terms of heat radiating from the glass itself.
I live in a primarily warm climate and I have done a lot of attic upgrades that almost eliminate the need for air conditioning but the windows are the major contributor now.
So my questions are-
1. Is it OK to put the reflective film on the inside glass of a double pane unit?
2. I'm considering replacing the slider with a new unit. The manufacturers have glass options that have hot climate low-e coatings. Do these make a significant difference over clear double pane?
Of course the best option is to shade the windows with trees or awnings etc. and I'm looking into that also.
Thanks
#2
Yes...LoE and gas filled works. Regular double pane really doesn't do anything about solar heat transfer. ANd you are probably correct about the glass getting hotter than a single pane...esp with the film.
Many manufacturers will not warranty seal failure or stress breakage with the films. They also aren't needed with newer higher quality windows.
Many manufacturers will not warranty seal failure or stress breakage with the films. They also aren't needed with newer higher quality windows.
#3
They told us once at a window dealer's meeting about the whole voiding the warranty thing when you put a film on the glass. I vaguely remember them saying that it can cause heat buildup between the panes due to the low-e coating and then a 2nd reflective surface. kind of like putting an ant under a magnifying glass.
This can probably happen whether there is a low-e coating or not since the glass itself is a refractor.

#4
Makes sense, the inside glass is much, much hotter than the outside glass. And I don't think they can put that film on the outside because it won't hold up.
Anyone know, is removal a matter of a single edge razor and some soapy water?
Anyone know, is removal a matter of a single edge razor and some soapy water?