Hi there. Perhaps someone has some idea of what my problem is and/or how to trouble shoot it. Contrary to what is typical, when I turn my furnace on each winter immediately all of the windows in my home (twice as badly upstairs) begin to sweat or collect lots of moisture and water on them. This problem is rotting my wood windows. I wipe them down every day just to find more water the next day. It is frustrating and damaging to my house. We must have too much moisture in the air. Usually a furnace dries a house out, hence the need for a humidifier (which we have but certainly don't use). This is an 11 year old house with original anderson windows. Am I destined to use damp rid and run the dehumidifier all winter? And could this be a sign of a more serious problem? Is the house not 'breathing' or venting properly? Thanks suz

The house could be too tight. Are the bath, dryer & rangehood vents terminated to the exterior? Is the attic properly vented? If you have a basment or crawlspace, is it always damp or get water in it when it rains?These would contribute to moisture in the house. High moisture could lead to a serious problem.. mold.

I would have to agree with the source or location of your furnace. In a house of your age, it's too new to be new construction moisture (from slab, foundation, etc.) but way to new to be having condensation like this.

You're on the right track though, too moisture in the air. Contrary to intuition, wet air actually rises, which might explain why the upper level windows are sweating more.

Sometimes a new home can be built too tight. Verify that you have a 'fresh air vent' installed on the hvac unit. Check to make sure that you don't have a moisture issue in the below grade areas of your home. Dryer vent and bathroom vents should be vented outside the house. Verify that the humidifier is actaully off.

Beyond these basic items, and assuming you're not running a green house in your home, you'll need the help of a specialist. Someone that can test moisture content of the air as well as materials. By compartmentalizing your home, you should be able to identify the moisture source.

Would love to hear if/how you resolved.