It is condensation from the colder outside temps, however the moisture being condensed is higher in an occupied room than one that rarely has human entry and normally is closed off. So there will be higher humidity in an occupied room and more likelihood of mold/etc. because of it.veloman said:I don't think it was from me being there though, I think it was condensation from differing temperatures.
As a sort-of example, when all the dogs sleep in here with me, my window A/C unit sometimes freezes up on the interior coils once the outside temperature drops far enough fast enough, just before dawn. But that almost never happens if only one of them is in here (it's a near certainty that at least one will stay in here; if it werent' for that I could probably say that it never happens unless more than just me is in here).