Window condensation

[Tin Lizzy]

Hi All,

I'm new here and hope I can get some answers to a problem.

My detached house house is 10 years old, front faces north. Every morning at this time of year the upstairs bedroom windows on the inside are covered in condensation in so far as I have to spend quite some time wiping the inside panes down and mopping up water off the sills.

These are double-glazed windows, there are no draughts from them as I recently had the supplier out to correct any problems with the seals. We have oil-fired central heating, the boiler was only serviced last August. All the vents are clear in each bedroom. I am really sick of this job every morning and am wondering if there are any trades people out there who have a remedy for this or any solution whatsoever. What is the cause ?
The rooms are not overly heated in the morning and there is no other dampness or source for this moisture.

 

[onq]

We have the same problem.
The condensation is caused by the people sleeping in the room, a cold surface and a lack of ventilation.
Permanent Ventilation is often blocked up and slip vents in windows are often closed.
Two adults sleeping in the room cause a lot of condensation simply through breathing out water vapour. and oddly enough on these cold nights, perspiration, assuming they're warm in their duvet.

If you don't believe me try sleeping downstairs or in another room and you'll see that there will be no condensation in the bedroom that morning.
Having said that, if there IS, that points to some other cause and you could revert here and if no-one else responds and I don't see your post you can PM me.

The similarities continue: front windows can be quite large - servicing what are often the largest rooms in the house.
Despite being double glazed, the surface of the window is impervious and relatively cold, ripe to collect water vapour.
In addition, people sometimes use heavy or insulated curtains at this time of year - they are not vapour tight [few things are] and the space behind them is unventilated and traps the moisture.

Can I say that all this is a relative thing and five minutes in the morning with the window opens clears this up.
Can I also say that I have seen this in modern apartments in Dublin 2 - only recently built and you could tell which windows had the integral vent blocked and which didn't.
Matters can be improved by upgrading the windows and wall insulation and then
(i) installing integral window vents [and leaving them open]
OR
(ii) sealing the house and fitting a Mechanical Heating and Ventilation Recovery System.

If you decide to do something about this, and need cutting edge advice on stuff like this, including empirical data on how walls deal with water vapour, you could contact; -

http://www.josephlittlearchitects.com/

I'd suggest an e-mail to his office first to see if he's free to advise and unlike here, expect to pay for professional advice.
Apart from having spoken to him at Plan Expo and read some articles by him I have no connection with Joe's office.

On the other hand, you might want to do some background reading on Joe's work:

http://www.josephlittlearchitects.com/papers.html

HTH

ONQ.

 

[Guest110]

I also have this problem in the bedroom. It is a nuiseance as it is going onto the bottom of my blinds !

 

[Stapeler]

Consider getting a dehumidifier, it would help the situation but won't fix the problem.

 

[Bar]

I also hav this problem but our house was build in 1979 and we only moved in. We have noticed this problem since the cold weather came in but the house is very cold in general. We recently were advised to check the attic insulation and there was little or none so we are going to insulate and hopefully this should help both problems. We were told its from having the heating on and the cold air closer to window hitting the heat rising from radiator. Will keep you posted.

 

[Sconhome]

I presume there are no room vents or if there are they have been blocked up. Cross ventilation is very important to allow management of water vapour trapped in a building envelope.

I second onq's opinion Joseph Little and recommend checking out his Construct Ireland articles on insulation of hollow block walls and the problems created by dew points in construction. You can find the articles on his website.