We are studying Humidity and Condensation right now. With the cold weather last week and the interior walls not completely dry from the last coat of earth plaster, we had a ton of humidity inside the house and, consequently, a lot of condensation on the windows and doors. Here is a graph and a couple links that our friend, Kyle, sent us. The above was taken from this link (click here).
Kyle also sent us two other links. The first one is a climate/humidity table that we are still trying to understand completely. The second one is a, "A Brief Guide to Mold, Moisture, and Your Home" that is taken from the EPA (Environmental Protection Agency)website in The United States. Thanks Kyle!! Great links and information!!
FYI: After posting the above, I drove to the genba (build site) and saw the current temperature inside the structure is 10 C (50F) and the humidity is about 88% inside. This is on the 1st floor in the back (North) corner of the house. I would guess that other areas of the house will have different temperatures (warmer and colder) and the 2nd floor probably has a bit lower humidity because the walls are drier up there (they were plastered first and don't have to compete with the concrete flooring on the 1st floor). The goal right now is to get the temperature inside up to something constantly between 16C and 21C (60~70F). IF this is done, the walls will dry more quickly and the humidity will fall.