French Doors reveals moisture.

[MDC]

I just read right through this fascinating thread. There wasn't one mention of what you might cover the windows with at night - blinds/curtains etc.

 

We live in a house built in 2016 of blocks and all that. It has double glazing. The north side is colder than the south etc. We get condensation on the windows. If we left the blinds completely shut at night, we'd eventually get the black stuff on the window frames and reveals and it would develop from there.

 

So, from September to March, we open the blinds a minimum of 5 inches from the ground/sill so the air isn't trapped against the cold glass/frame/handles/key hole and so on. This is from 11pm at night. There is no condensation. The rooms have the same humidity, but the warm air isn't trapped against the coldest surface. 

 

We had the same issue in our previous eco-house, which had an MVHR. 

 

Another thing, we considered buying a house near Bristol, which had a pair of very nice modern efficient extensions around an 18th century grade 2 listed tower. It had MVHR and an incredible ground source heat pump. It was about 220 sq metres. The electricity bills were out of this world [in my opinion] and the tower was full of mould [I'd say the bedrooms there were unusable]. The new and the old just didn't mix humidity wise. The owner was eco-friendly and wanted to save the planet, but he'd actually created a damp monster in that house, by mixing modern insulation in some areas, with no insulation in others. 

 

Just saying.

 

 

[joe90]

4 minutes ago, MDC said:

The new and the old just didn't mix humidity wise. The owner was eco-friendly and wanted to save the planet, but he'd actually created a damp monster in that house, by mixing modern insulation in some areas, with no insulation in others. 

Very interesting and ties in with what a lot of people here have been saying about Zoots old stone cottage.