Condensation between double glazing.

[Gavmacp]

My mother has an old house with sash windows. My father many years ago put a secondary glazing on the inside to make the window 'double glazed'.
Mother has a problem that condensation build up and must run down causing the paint work/wood to turn black.
Is there anything she can put in between the windows to stop this. Obviously not a lot of space between windows?

[The Builder]

Factory double glazing features a sealed void between the panes of glass. Air is drawn out, creating a vacuum. An inert gas such as argon is then pumped into the void.
DIY double glazing can be very effective, but there will always be air in the gap.
I'm afraid I can't think of any way to overcome this. I guess it'll always be a case of removing the secondary occasionally to clean up.
I guess a small pack of hygroscopic crystals would soak up some of the moisture, but it would have to be replaced fairly frequently.

[mk1975]

hi, it is not relevant, but if you are in Scotland and thinking to replace those windows, dont touch the company called Perfect Glazing.they are rubbish and have very bad feedback!!