A couple of years ago, spring humidity in southern China.

2 minute video:
 Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Wow, is that bad building and ventilation or would that be normal at 100%?

It's because it's been cold in the region. Then the weather changes & warm very humid air blows in from a different direction.

The moisture in the hot air then condenses in the cold environment as the cold air can't hold as much moisture.

We get this in Sydney, but nowhere near as bad. Cold south west winds for a few days & everything cools down. Then we get a north east wind bringing warm air off the Pacific Ocean.

Just recently we had cold 20% humidity air from the west, then over a few hours humidity increased to 90% from the north east. But it hadn't been quite cold enough for the moisture to condense & the warm air didn't quite have enough humidity to then condense.

Ocean temperatures have been really high this year. Over winter a few times this year we have mopped up pools of water which has condensed on our windows. It doesn't help having single glazing. But at least the cold glazing is a "dehumidifier" & we can mop up the water.

As the sea gets warmer this problem will only get worse, substantially!



This is worth a read. A bit hard to get one's head around it at first, but then it clicks & you can see why the moisture comes out of the air as it gets colder.

Understanding psychrometric charts and dew points
https://angelicaisa.com/blog/understanding-dewpoint Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18