On 12/25/11 12:55 PM, leza wang wrote:
i have 2 old windows upstair in my 1.5 house. they both old and i see
now water inside them (please see http://imageshack.us/photo/my-images/26/img0857wa.jpg

it is like when you put a glass of cold water outside in a humid day
in the summer. how can I fix that? i thought putting humidifier would
help but i also thought humidifier should only be used in summer time
not winter.

please advised and thanks for all of you.

Mine do that sometimes. It happens when the temperature of the glass
gets down to the dew point of the air in the house.

In winter, a heat exchanger might be more practical than a dehumidifier.
Fogging is more likely when the glass is colder. I'm more likely to
get it if I close blinds and curtains, and in unheated rooms.