Originally Posted by
stut
I wonder if it's the same phenomenon as in the UK, and a simple lack of ventilation. Newer housing stock is significantly less draughty - great from an environmental/cost point of view in a colder climate, but the ventilation (extractor fans, etc) that gets built in is pathetic - not just in the bathroom, but in the kitchen, and wherever you dry clothes (oh, for the space to put a tumble dryer...)
Could be the way British house are heated which I think is still via hot water radiator? North American houses that have central heating generally use forced air heating which does serve to ventilate the house even if the air doesn't escape. Some places have air exchangers (which also uses heat exchangers to warm up incoming fresh air with warmer outgoing air) to intake new air and exhaust staler air from bathrooms and whenever a certain humidity level is reached.
And extractor fans are said to be designed to be noisy to muffle bathroom noises.
I've been criticised by guests for installing more-expensive and effective but deadly-quiet Panasonic fans.
A lot of extractor fans don't work because they don't ... vent outside! Or if they do, they are trying to force air up significant heights and don't have the power to do it.
People are also less willing to air out the house on a regular basis, particularly when it's cold - and the heating is on more than previously. It seems the norm to leave it on overnight
With in-floor and latent heating, it's said that varying the temperature too much in a given day (or over night) is inefficient. I sort of like the idea of cooling myself as I don't sleep well in warm rooms.
- something I wouldn't consider and would have been anathema to my parents, even in a draughty old house where I used to enjoy waking up to the sight of frost on the inside of the windows, and knew the route to walk to the stairs with the hot water pipe running underneath!
Ah yes, single-pane windows which are very poorly-insulated (as in huge gaps) too.
A £35, table-top dehumidifier can work wonders. But there still needs to be a certain air flow.
The trouble with dehumidifiers is that they do suck energy, and become less efficient as ambient air temperature gets colder. They work by cooling a coil (almost like an air conditioner) and humid air drawn through has all the moisture condense on the coil, much like wearing spectacles in a a/c room or car in the tropics and then stepping out into warmer high-humidity environment.
As for the wet rooms - I assume there's some kind of lining? .
Hopefully built on a plastic or some impermeable pan.