Testing Double Glazed Unit

[DIYWell]

Is there any way to test if a DG unit has degraded?

I know the standards allow for a percentage leak of the internal gas per year, but I'm wondering if one particular unit has failed. It doesn't show any condensation or other signs of failure.

 

[ronniecabers]

Unfortunately there is no way to tell until you start getting the internal misting. Sealed units have an expected life expectancy of 10-15 yes but can fail early or last longer . There are lots of variables! As a general rule I find south facing sealed units fail first. I have seen units with the spacer bar ( bit the keeps the two panes apart ) bowed into the unit but the unit hasnt failed.
Only gases used with sealed units are Argon and Krytpon ( krypton not very often as it's blinking expensive! ) . Sealed units are not vacuum and it's generally the air in the factory at time of production that used to be in then before gases. It is generally understood in the industry that gases will leak out with 5 years but unless you have a very expensive ' spark tester ' this can not be proved

 

[DIYWell]

Thanks.

It's quite a thought that most folk think of DG as fit and forget, not fit and replace every couple of decades. Then again, with folk changing houses, it's unlikely they know how old their windows are. Makes you think twice about energy efficiency.