A 3 meter cube is 27000 liters. So, yeah that holds about half a liter of water. That’s great if it’s a sealed box, but it’s not. Homes are leaky, and typical

A 3 meter cube is 27000 liters. So, yeah that holds about half a liter of water. That’s great if it’s a sealed box, but it’s not. Homes are leaky, and typical HVAC systems will replace all that air at least 5 times an hour. So that’s 2.5 liters, or about 2/3rds of a gallon… per hour. Now of course this is assuming worst case of going from bone dry to fully saturated, but even if you want to raise it 20 or 30% the numbers would be a third of that, but still. Humans are very sensitive to humidity. I don’t doubt your towel setup makes things feel more humid, but if you were to actually measure it with a hygrometer I bet the actual number is changing way less than you think.