Mould, condensation and dampness; What you need to know.

[@Polecat54941]

Heat your home and open all the windows,and buy good insulation that works with the windows open great advice there thanks

[@frankw9836]

i moved into a rented House here in Northern ireland last April. Even in the "summer" time i noticed high humidity above 80% . Now in winter it's the same but i noticed water running down my windows and mould building in the bedroom, corridor and bath. also my clothes and damp and mouldy. I bought myself a 12 l dehumidifier which runs all night and its full 12l in the morning !! I now sleep with the window open (freezing cold) i have vents , crawl vents i believe they are called. I closed them for a week (no difference) what can i do ??

[@worshipthecreator9081]

Should we open windows in winter??

[@phils749]

Such a shame, a nice clear well presented video but giving out bad advice that will undo all the good in the winter. You shouldn't open windows if the weather is raining, damp, etc because you could let in more moisture than your letting out, this is the simplest way to put it.

[@holtemporium]

Nonsense, I suggest that you familiarise yourself with the science of Psychrometrics which is the thermodynamics of air moisture mixes. An outdoor relative humidity of 90% at 5 degrees has a much lower water vapour content than an indoor relative humidity of 70% at 20 degrees and the vapour pressure indoors is higher as well. The second law of thermodynamics equates to heat moves towards cold. That's why we insulate our homes to slow the passage of warm air that's trying to leave.

[@phils749]

I am familiar with Psychrometrics etc, I would suggest you read more carefully as the word could is the main word, if there was no issue with having windows open on damp, wet, or moist days then the general advice would be to have windows open at all times, but when your dealing with social housing tenants the majority are not familiar with relative humidity, dew points, etc so its easier to recommend not opening windows on wet, damp or moist days. Please be careful not to get a nosebleed while up on that high horse!

[@holtemporium]

Then explain, using your knowledge of Psychrometrics how you arrive at your conclusion.. "You shouldn't open windows if the weather is raining, damp, etc because you could let in more moisture than your letting out, this is the simplest way to put it"@@phils749