The setting is highly dependent on the windows and whether they are double or triple pane. All you need to do is look for condensing moisture. In MN during a brutal cold spell, I always turned the humidity down even with triple pane widows.
BTW, my definition of brutal was for extended time below zero, or a night less than 20 below.
My wife always complains when I adjust our humistat down to 20% when its forecasted to drops below 15 degrees. She doesn’t want to believe me when I speak of black mold developing but I’ve seen it countless times over the years in customers homes when there was no other explanation than too high of humidity in the home.
Paul
