http://www.ianrpubs.unl.edu/epublic/live/g1849/build/graphics/g1849-1.jpg Air at 0dc(freezing) and 100%rh heated to 24dc makes the rh about 50% Humidity is relative hence RH. Air's ability to hold moisture decreases with temperature. Research how a dehumidifier works. Your moisture content remains the same but as the temp decreases the ability to hold water decreases and the rh increases. Sent from my iPad using Grasscity Forum