Let me be clear, uncontrolled ventilation is bad news, it causes transient condensation. Ventilation has to be managed through the judicious use of extractor fans and not by opening windows! If you know anything about condensation you'll know that warm air holds more moisture than cool air. It's more important to keep the building warm when managing condensation damp and you can't do that by opening windows. It's very easy to glibly advise residents to open their windows but the fact remains that this is bad advice that needs to be unlearned by many more more than you Noseall.
Little bedroom's ceiling is infested with moulds
- Thread starter sknodiy
- Start date
Let me be clear, uncontrolled ventilation is bad news, it causes transient condensation. Ventilation has to be managed through the judicious use of extractor fans and not by opening windows! If you know anything about condensation you'll know that warm air holds more moisture than cool air. It's more important to keep the building warm when managing condensation damp and you can't do that by opening windows. It's very easy to glibly advise residents to open their windows but the fact remains that this is bad advice that needs to be unlearned by many more more than you Noseall.
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Can you explain how opening a window to a room full of condensation is bad please?
He is correct, 'open the windows' is pretty much 1950s thinking.
Opening the window only works when the window is open (you can see the flaw in that I hope?).
Opening the window will reduce internal temperatures far more than appropriate and controlled ventilation. This means as soon as you close the window, you now have colder wall surfaces (colder relative to if more heat had been retained) leading to further condensation.
The problem is we have a lot of ****ty housing stock. Such as poor to no wall insulation and prodigious cold bridging. Preventing condensation for such buildings requires excessive ventilation, therefore excessive heat loss (high bills).
Not everyone can leave windows open at night, opening windows in the day will do little to stop night-time condensation. Nor can everyone afford the bills to ramp up the heat and keep good level of ventilation.
Various councils have spent a lot of money upgrading old stock, whilst producing case studies, to combat this problem.
More ventilation means more heat output is needed, it is NOT cheaper to do this in the long run, only in the short term is it cheaper.
As to renters, the 'open the windows' mentality is outdated and only allows landlords to avoid spending any money upgrading their stock.
Opening the window only works when the window is open (you can see the flaw in that I hope?).
Opening the window will reduce internal temperatures far more than appropriate and controlled ventilation. This means as soon as you close the window, you now have colder wall surfaces (colder relative to if more heat had been retained) leading to further condensation.
The problem is we have a lot of ****ty housing stock. Such as poor to no wall insulation and prodigious cold bridging. Preventing condensation for such buildings requires excessive ventilation, therefore excessive heat loss (high bills).
Not everyone can leave windows open at night, opening windows in the day will do little to stop night-time condensation. Nor can everyone afford the bills to ramp up the heat and keep good level of ventilation.
Various councils have spent a lot of money upgrading old stock, whilst producing case studies, to combat this problem.
More ventilation means more heat output is needed, it is NOT cheaper to do this in the long run, only in the short term is it cheaper.
As to renters, the 'open the windows' mentality is outdated and only allows landlords to avoid spending any money upgrading their stock.
If I'm in the shower and I open a window, it decreases the condensation far quicker than any fan can.
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I did, in the previous post to yours but what do you mean by a room 'full of condensation'. How do you prove this before offering the advice that windows should be opened? Most condensation is cold surface surface condensation caused by poor insulation and cold bridging so ventilation is only one factor and in this case would do nothing more than reduce internal temperatures so that the air immediately has to give up humidity as condensation, it also chills internal building fabric, thereby reducing dew point temperature in the room.
As I said earlier, yo really need to unlearn this piece of bad advice.
You have just quoted one of the biggest myths to support the ridiculous idea that opening windows is good. Opening windows in bathrooms only appears to deal with the condensation but in fact the humidity is immediately given up as condensation in the room thereby giving the impression that it has exited via the opening window. This is what I mean by transient condensation!
FFS this a bedroom we're talking about.
Obviously a jumped up extactor fan salesman John.
How does opening one window chill the fabric of a house?
Whilst I agree with the insulation ventilation thing, I think you are over-dramatising the opening of a window.
Are you an extractor fan salesman?
No, you're talking rubbish Noseall. I'm not a jumped up extractor fan salesman, or indeed a jumped up builder like yourself. I'm a Chartered Builder and a Chartered Building Engineer. I've been teaching damp investigation and remediation since 2006 and also do a great deal of expert witness work in this area. You're typical of know it all builders who are stuck in the past and too stubborn to admit you're wrong and take on board good advice.
Are you going to answer my question? How does opening a window chill the fabric of a house?
Are you funded by Vent-Axia?
I have grateful, paying customers. Far more beneficial to me than fans.
Ah, I see to save face you've moved the issue to asking how opening one window chills the fabric of a house? I feel sure that its not a question that anyone but you needs answering but do you even understand the basics of heat loss in buildings and can you not understand how a lower external air temperature will reduce the temperature of the internal building fabric when a window is opened. Or are you simply going to get into a silly discussion about how opening 'one' window won't do any harm? Do you even understand that warm air holds more moisture than cool air?
You need to stop asking silly immature questions to divert attention from the fact that you're wrong and are commenting on issues of which you know nothing about. Try reading BS5250, which adopts the same position as me and the British Standard is also not funded by Vent Axia, though I'm sure you're not beyond suggesting that it is to save face.
You need to stop asking silly immature questions to divert attention from the fact that you're wrong and are commenting on issues of which you know nothing about. Try reading BS5250, which adopts the same position as me and the British Standard is also not funded by Vent Axia, though I'm sure you're not beyond suggesting that it is to save face.
Wrong about what exactly?
All I know is that when I put my specs on to trim my beard they steam up. If I open the window they clear.
Now get off your high horse and explain please. And stop being so arsey.
All I know is that when I put my specs on to trim my beard they steam up. If I open the window they clear.
Now get off your high horse and explain please. And stop being so arsey.
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