Originally Posted by
realazy
If you open the blinds half way up, it helps a lot. I have triple pane windows with the humidity reading at 29% and it still frosts up a bit if I have the shades open only 2-3 inches at the bottom.
If you leave the furnace fan on all the time, the circulating air helps warm on the windows more too.
To lower humidity quick, you can open the door or windows for a little bit, the -30°C air basically has no moisture.
As for the bathroom fan dripping, you probably have compacted insulation in your attic and it's not doing its job as well anymore.