shipping container workshop?

[EddyCurrent]

At the end of the day it's physics, warm air condensing on a cold surface, warm air holds more moisture than cold air.

From Wiki

"The dew point is the temperature at which the water vapor in a sample of air at constant barometric pressure condenses into liquid water at the same rate at which it evaporates. At temperatures below the dew point, water will leave the air. The condensed water is called dew when it forms on a solid surface. The condensed water is called either fog or a cloud, depending on its altitude, when it forms in the air."

"Relative humidity of 100% indicates the dew point is equal to the current temperature and that the air is maximally saturated with water. When the moisture content remains constant and temperature increases, relative humidity decreases"

Control that lot and you're there !

So with my dehumidifier I keep the relative humidity below 50% whatever the temperature and that's mostly to keep my wood right but also keeps rust at bay. If I put my wood burner on the relative humidity can drop to low 40's%