@Benji @JonKramer Yes, that is the natural humidity if you live in a wind tunnel. At the minimum have a steamer on at night, or you are a covid magnet. We, in Canada, usually have sealed windows. In fact, the new super houses need an energy air exchanger to stop the windows from raining.
@Benji @JonKramer For the old windows, I used to use that 3M shrink plastic over the frames. Then you can just peel it away in the Spring.
@Benji @JonKramer You won't able to buy any of this in the US right now. :)
@hasmis @JonKramer Don’t need it … I live in So Cal.
@Benji @JonKramer Ok, we'll just laugh at you when you want a glass of water. :)
@hasmis @JonKramer lmao:ablobjoy: Yes that is for sure. Here we’re about to burn and wither, while the rest is drowning and sucking snow cones.
@Benji @JonKramer Get the huge generic rolls and tape. Crack open a window in the furnace room. The chimney effect puts in a big pressure difference.
@hasmis @JonKramer that’s also natural when it’s cold outside and warm inside. The vapor pressure vs temperature shows that , if you keep vapor pressure (moisture content) constant and increase temp, the relative humidity (relative to the curve that separates liquid water / vapor) drops. So the air is always drier indoors in wintertime, unless you sealed your windows and are able to increase moisture content artificially (humidifier, shower etc ). No need to be in a “wind channel” 
@Benji @JonKramer If you seal the house, then you can get a natural 40% in the winter, which is good. Above that, the windows rain.
'Wind tunnel' was my term for a leaky house, which can go below 20%, which is bad.
@hasmis @JonKramer yup, makes more sense now. Here in SoCal lots of old building like the one Iive in have single pane windows, with these louvre/jalousie windows, leaky as can be… Hard to control the humidity and temp inside.
@Benji @hasmis I grew up in Venice, single pane windows, house made of redwood in the 1930s. It was drafty but never too hot or cold. I really don't remember how it was heated... but no AC.
Here in Kentucky, this house was built in 1895. 3 stories, solid brick, original windows mostly. All single pane, all drafty. And all the worse for wear after 130 years. And all "protected" by the local historical zone laws that prohibit new energy efficient affordable windows.
But, my post was mostly a joke about it being zero degrees, not so much a complaint. Just for general info, zero (f) is COLD around here. I mean really cold. 20 is cold. But, this is a new normal. In the 80s we had a solid week of -20. Climate change is real. I know my windows suck, and I know what would be best to fix/replace them. I fix things and modernize as I can afford it... but really, the house stayed 70 degrees above the outside temp, so I'm OK for now.
@hasmis @JonKramer I deleted my post as I understood your point mid-way. :) need good windows/ insulation to control indoor humidity, otherwise the moisture content (vapor) will be the same as outside and produce drier air inside.