On cold days(-20) I get frost on the inside on the bottom of my windows . Is that seal problem with the windows or a moist problem in the house . The frost only accumulated on the bottom. The windows are 10 yrs old ,double pain.
Answer:
In the cold weather it is normal to have frost on windows so we don't worry a whole lot about it. It takes only ten F degrees of difference in temperature from one side of the glass to the other to reach a dew point. And that dew point shows up as condensation on windows first because they're so exposed to the temperature difference and at the same time are quite impermeable. You might want to try placing an air deflector over the heating grill in front of that window to direct warm air away from it when the furnace is on and that will help some. If it concerns you, consider this: cold air holds more moisture than warm air and is, therefore, heavier. As air cools, it falls and keeps falling until it reaches the lowest level in the house. It cannot fall beyond the basement floor and that is where it has to be collected and pumped outside before that moisture gets a chance to condense in order to get rid of the moldy, musty odour and/or avoid it in the first place. A booster fan (250 CFM +) is available as a ‘pop in’ unit to fit 4”, 5” or 6” round heating duct. This can be installed in a totally separate duct line that is at least six feet from the nearest heat source. A timer on it will ensure that it operates only during the night (9pm to 9am) so cold, moist air it pumps out is not replaced by air that brings in even more humidity from outside. All joints and seams in the duct are taped and sealed for maximum efficiency and rather than a heating-type grill it should be a return air-type grill. To avoid having to core another hole in the foundation wall, this system can be vented, via a “TY” through the clothes dryer vent. Because none of the doors in the house go all the way to the floor, cold, moist air should find its way to that grill.
