Glass correct way around

[Phil_h]

Is there a way of telling if the glass has been put in the correct way around for the Low-E glass?

 

[wms]

on a paterned unit the glass pattern should be on the outer pain .why do you ask.? ]]]]some times when viewing k glass you can see a haze on the glass in certain sunlight due to the refraction on the coated surface.

 

[squowse]

you can buy a meter that will tell you but i expect they're expensive. local authority building control will have one.

 

[philipdayton]

If you look closely from an angle you can sometimes see which pane has the coating on it, however, it does not affect the U value of the sealed unit even if it is fitted back to front.

 

[squowse]

it does not affect the U value of the sealed unit even if it is fitted back to front.

i don't think that this is correct

 

[^woody^]

www.merlinlazer.com/Low-E-Coating-Detector-NEW

You wont be able to tell with an certainty just by looking at the glass.

 

[philipdayton]

it does not affect the U value of the sealed unit even if it is fitted back to front.

i don't think that this is correct

I think you'll find it is....
The g value is affected but the U value remains the same.
The emmisivity of the coating on the glass is what alters the U value of the unit, the orientation of the coated glass makes no difference

 

[squowse]

i am quite willing to stand corrected! i will look into it...
it always seems to be considered a big deal.

 

[chappers]

I have been thinking about this and my initial thoughts were that phil was probably wrong but I believe he may be correct. the u-value of a product is a measure of how much heat is lost through the total unit.
the coating on k glass I believe is normaly on the outer face of the inner piece of glass now if the unit was fitted so the coating was on the inner face of the outer pane the heat would be reflected in the same way and be prevented from reaching the outside, thus the u-value would be preserved.
however this reflected heat would warm up the gap in the sealed unit and not be reflected back into the room so much. Therefore having the same u-value but being less efficient

 

[philipdayton]

I have been thinking about this and my initial thoughts were that phil was probably wrong but I believe he may be correct. the u-value of a product is a measure of how much heat is lost through the total unit.
the coating on k glass I believe is normaly on the outer face of the inner piece of glass now if the unit was fitted so the coating was on the inner face of the outer pane the heat would be reflected in the same way and be prevented from reaching the outside, thus the u-value would be preserved.
however this reflected heat would warm up the gap in the sealed unit and not be reflected back into the room so much. Therefore having the same u-value but being less efficient

Exactly, as an insulating unit which prevents heat loss, it's not affected.
However you may lose some reflective benefits (these benefits are slightly dubious anyway).
At the end of the day the most important thing is to prevent heat loss.

 

[^woody^]

I've just read a post on another forum and it mentioned using a metal detector on a really high sensitivity which would be set off by the coating -so it can be detected which pane has the coating.

I've not tried it, so whether its correct or not I don't know

 

[Phil_h]

Thanks,

The fitters removed all the k-glass stickers before they were fitted so did not not know if the glass was fitted back to front or not.

Just wanted to know with regards preventing heat loss.

So is the conclusion is it does not matter which way around the glass pannel is fitted?

 

[chappers]

Doesn't matter that much as has been said BC will probably have a laser which will tell you, if you are that concerned.

 

[diyman09]

Regarding the pattern on the outside. This is not always true.

Lead units for example.