just brew it! wrote:
@drfish - I wonder if aiming a fan up into that corner would warm it up enough to prevent the condensation, or just cause more condensation to form due to the increased airflow?
Use an IR lamp pointed up there, like the ones for the bathroom to dry it out and stop more from occurring. Otherwise get some closed-cell foam insulation and put it up. The real problem you will have is when the ice melts, gets the drywall wet, and then you get mold. People get all wound up over mold these days, like it is toxic or something. Otherwise adjust the furnace's humidity lower so the dew-point works out less than the measured 22F.
We keep our house humidity very low, especially in this weather. Something like 5, 6%. Not by choice though, this is a wood-burning stove plus plenty of "natural ventilation". Our dew-point usually isn't much more than the outdoor temperature at the most. This prevents disease transport, but results in bloody noses and generally chilled feeling no matter the temperature. Older houses are "fun".