In message , Mark
Allread writes
On Fri, 20 May 2016 03:45:40 -0700, tabbypurr wrote:



Unsealed DG mists because the inner space is exposed to the same water
vapour level as indoors, but the temp is lower. Expose that space to the
lower outdoor water vapour levels and it simply does not mist. External
glazing does the latter, internal glazing the former.


My externally glazed units has one that is now misting up. Or is this the
exception to prove the rule?

The misted ones I have are in timber windows so externally glazed.

20+ years though!


--
Tim Lamb