CONDENSATION

There is no real magic to condensation. Air can carry moisture in the vapour phase. Condensation happens when the temperature drops below the dew point. That's the scientific explanation. So to some practical steps (some of which are not really practical, more 'theory'):

1. eliminate cold spots in the room where the wet air hits the coldest surface. Assuming it is the windows maybe some tighter fitting heavier curtains. Or get a window that has better insulation, so the inside is not quite so cold. Have you considered upgrading the double glazed unit (not the complete window itself)?
2. Allow some of the moisture laden air be replaced with fresher air. Open a door, open a vent etc.
3. Heat the room, so that all parts of the room remain above the dew point (maybe not practical, not in a bedroom).
4. Directly remove moisture from the air (i.e. dehumidification). Not pleasant trying to sleep in air that is too dry!.
5. Reduce or remove the sources of moisture. Kick one of the kids out of the room.

So the 'low hanging fruit' is really 1. and/or 2. above.

my daughters box room is similar. Best solution is to use a dehumidifier, when I plugged it in this morning it said that the humidity was 95%!!!!!!

The windows are good , but the curtains and blind means that the heat isn’t heating the glass , making it the coldest part.

She often gets black mould on the ceiling when she doesn’t open a window or plugs in the dehumidifier

Circulate the air in the house, something to move it around.

I would install mechanical ventilation if you have easy access to bedroom ceilings through the attic? Then block and insulate the wall vents.

Damp air gets sucked out through a fan in the attic and replaced with fresh air that comes in through all the air gaps in the house. Probably plenty of existing gaps in a 1980s house.

Humidity sensors in the fan control the ventilation speed so you're not pulling in so much cold air that it causes the temperature to drop.

Simple living generates moisture from people breathing, cooking vapours, laundry, showering. So address these matters as best you can. With cooking, use extractor over hob, lids on saucepans and simmer rather than boil…. with bedrooms air out bedding daily even just throw back bedcovers for the day. Open windows on southery aspect daily. Deal with wet shower walls with squeegee and a cloth, open window before running shower. Dont dry clothes on rads, use outdoor line as much as possible. Double glazing was best thing we did for window condensation but we also run two dehumidifiers and there is always window open in bathroom. Except for coldest nights I would have window in bedroom open as well.

The only simple solution is to open the bedroom windows every day for as long a period as possible - the longer the better.

Hi, do not dry/hang damp clothes, on rads ,indoors etc.Use a dehumidifier,they are cheap to run.Vent some of the down stairs windows ,to cool the house a bit,at night , as such.Put some tubs of salt on the windows, this draws moisture from air,helps a small bit.I got new windows as well ,and still have some condensation,at the end of the day,i think the houses are a bit too warm.Good Luck.

Something that looks like this. One fan unit in the attic that's ducted to vents in the ceilings of the rooms. The fan exhausts through the roof.

They're fitted to a lot of new homes. The exhaust has a humidity sensor that controls the fan speed. Mine is quiet enough. I hear it only at night when the house is silent. I put it on a timer so it's off during the hours we're going to sleep, say 11pm-2am.

THe image shows air getting pulled in through wall vents, but as i said, there's probably so many gaps in a 1980s home they're not needed. We have trickle vents on the windows for the same purpose and I never open them.

Here's one I found online: https://www.bpcventilation.ie/duco-box-silent-mev

You can get much fancier heat recovery ones too.

I don't like the idea of opening windows, especially in winter. It costs enough to heat the house and a film of water on the windows isn't going to evaporate quickly in our damp climate. Prevention is better than a cure.

Same problem with condensation on the windows and black mould spots on ceilings in the bedrooms - i run a dehumidifier during the night and leave top sash of windows partially open. Every few months i have to clean off mould spots where the ceiling meets the outer wall due to high humidity.

Hi anyone any experience of PIV systems.Would like to hear of any first hand expeience.Tks