Environmental Graph Interpretation

Fri Nov 13 00:34:35 UTC 2015

If there are heat producing devices in the room, it sounds implausible
for condensation to occur in significant amounts unless the climate is
very, very humid. 

RH sensors are often very inaccurate, but you can get the indoor dew
point from the RH and the temperature[1], and if the floor is warmer
than the dew point there can be no condensation. If it is below the dew
point, there will be condensation - but the outside air cannot be colder
than its own dewpoint, so in this case something must be adding water
vapor to increase the absolute humidity in the room, or the floor must
be cooled by something other than outside air. (Or the temperature [and
dew point] of the outside air must be constantly falling while the indoor
air is lagging behind. This can only be a transient situation, and the
reverse should happen at some point, drying the floor again)

1: http://andrew.rsmas.miami.edu/bmcnoldy/Humidity.html