Other machines use massive amounts of energy to run a fan to pull air into the machine and extract what water it can, with no regard for the actual dew point of the air in which it is operating. (treehugger.com)
And, as pointed out, old crawlspace floor framing was not only warmer than the ground but also warmer than the ventilation air dew point. (buildingscience.com)
It happens when air with a certain dew point temperature finds a surface that's at or below that temperature. (energyvanguard.com)