Aluminium double glazing and lots of condensation.

[opps]

Back in the summer, I redecorated my mum's bedroom. The 40(?) year old powdercoated units were fitted into the old sliding sash boxes.

I suspected that the stains below the bay windows were caused by condensation that ran down the windows. Whilst decorating I ran CT1 around the windows (where the windows meet the timber frame).

Now that it is cold, the water pools at the bottom and is splitting the paintwork

I have recommended purchasing a dehumidifier but will it make much difference to bay windows with extremely thick curtains?

Thanks in advance.

 

[freddiemercurystwin]

Ventilation may help but often perceived as negative (understandably) when you're trying to heat a room, old aluminium windows will have no thermal bridge so terrible for condensation. You can try a dehumidifier but it's a bit of a game.

 

[Harry Bloomfield]

I have recommended purchasing a dehumidifier but will it make much difference to bay windows with extremely thick curtains?

Either, or both will help, but the only real solution is replacement. I had our replaced, a decade ago, no similar problems since.

 

[opps]

Either, or both will help, but the only real solution is replacement. I had our replaced, a decade ago, no similar problems since.

Cheers Harry.

I did suggest that going for uPVC might be a better option, but given her age, she has decided that it might not be worth the cost and disruption. ..

 

[robinbanks]

Insulated blinds/shutters?

Also, have you examined sources of moisture generation elsewhere? Can't do much about a sleeping person breathing it out but if the house is already loaded with moisture because of wet washing on rads etc it's a compounding of factors. Being humidity conscious may help

If your thick insulated curtains don't effectively block off convection (by touching floor/ceiling/walls either side of the windows then they won't really achieve much; air cooled by the windows flows out the bottom of the curtain, drawing warm moist air in the top which cools and condenses its moisture out on the window. It's thus essentially a passive dehumidifier, and keeping the moisture under control with a window vac may also help avoid paint damage

 

[opps]

Insulated blinds/shutters?

Also, have you examined sources of moisture generation elsewhere? Can't do much about a sleeping person breathing it out but if the house is already loaded with moisture because of wet washing on rads etc it's a compounding of factors. Being humidity conscious may help

If your thick insulated curtains don't effectively block off convection (by touching floor/ceiling/walls either side of the windows then they won't really achieve much; air cooled by the windows flows out the bottom of the curtain, drawing warm moist air in the top which cools and condenses its moisture out on the window. It's thus essentially a passive dehumidifier, and keeping the moisture under control with a window vac may also help avoid paint damage

Thanks for the reply.

The curtains just about touch the top of the angled bay window radiator. At the top, they are about 10" down from the ceiling.

Mum sleeps on her own in the room and leaves the bedroom door open overnight.

She does use drying racks on the floor above, but I wouldn't say that it is a "damp" house. It is a Victorian 9" solid wall property, and there are no visible signs of damp. Strangely, that room has the same brand of aluminium windows and my stepfather sleeps there, but there is little in the way of condensation on those windows. The curtains upstairs are much less dense. Mum's curtains (accidentally) ended up being sofa material (and as such are wayyyy thicker). My stepfather (on the 3rd floor) also leaves his door open overnight.

I was going to suggest a rather expensive dehumidifier that a customer of mine has (approx £450). Perhaps I should recommend a cheaper one to see if it makes much of a difference, and then consider upgrading.

Either way, I appreciate all of the replies thus far.

 

[richw]

I had some old Everest aluminium (with hardwood surround) double glazing in my house. No issues with the glass, but the metal would spend over half the year freezing cold, with the result being that it would run with condensation, and gather at the bottom of the wooden frames and/or the wooden window cills.

There was no thermal break between the aluminium on the inside and the outside. I am told that modern aluminium windows do have this.

I did wonder if I could glue UPVC strips over the aluminium on the inside (and maybe even the outside). My thinking was that the plastic would offer some level of insulation which might increase the surface temperature of the frame, which could reduce the condensation.

I never got around to it - all but two have now been replaced with UPVC. I am no fan of UPVC, but these frames don't run wet!

 

[Notch7]

Back in the summer, I redecorated my mum's bedroom. The 40(?) year old powdercoated units were fitted into the old sliding sash boxes.

I suspected that the stains below the bay windows were caused by condensation that ran down the windows. Whilst decorating I ran CT1 around the windows (where the windows meet the timber frame).

Now that it is cold, the water pools at the bottom and is splitting the paintwork

I have recommended purchasing a dehumidifier but will it make much difference to bay windows with extremely thick curtains?

Thanks in advance.

A tube heater on the windowboard might make all the difference, have it on during the night when the curtains are closed

Or as above suggestion: try gluing some upvc trims on the window frame sections

 

[Harry Bloomfield]

I did wonder if I could glue UPVC strips over the aluminium on the inside (and maybe even the outside). My thinking was that the plastic would offer some level of insulation which might increase the surface temperature of the frame, which could reduce the condensation.

That was an idea I had in mind, but never got around to, when we had ours installed. You can buy various profiles of UPVC, quite cheaply, from Eurocell. They have an online catalogue. The profiles are a sort of aerated PVC, so should be good as insulation. Worth doing one window, to test the idea, the frame outer edges would be easy, but the opening section much more difficult.

 

[robinbanks]

If you were going to do that it would be better to coat them with something that was actually insulating..