Condensation on brand new windows? You must be kidding me! It can and does happen. The frustration most people feel when condensation forms on new high performance windows is enormous. After all, they just spent lots of money to SOLVE condensation problems!
Why Me?
There are very few parts of the USA that don't have condensation problems. The first place that comes to mind is the Southwest. The humidity is low and temperatures can be high for the most part. Sure, there are parts of the Southwest that get snow and can get cold, but it sure doesn't have the humidity you find in the Midwest or Northeast on a routine basis. Higher humidity from the air and water vapor that comes up through the ground can cause all sorts of headaches inside a home.
Sources of Indoor Humidity
Plants, cooking, washing clothes, frequent showers, whirlpools, hot tubs, etc., all can liberate lots of invisible water vapor into the air of a home. Water vapor can also come from the soil around your foundation walls and under your basement floor or your slab.
In older homes, this water vapor can be hard to control. Old houses can have rock foundations or slabs that were poured directly on dirt. I used to live in such a house and the basement was constantly musty.
New houses can have vapor barriers installed on the damp side of the concrete. A simple vapor barrier on a foundation wall is hot asphalt spray. A fantastic vapor barrier AND waterproofing product on a foundation wall is rubber modified asphalt or synthetic rubber foundation treatments.
New homes can have great vapor barriers installed over the soil in crawl spaces.
Monitoring Humidity
As the outdoor temperature drops, the indoor relative humidity level must also drop, or condensation can form on even the best windows. You can measure indoor relative humidity with a hand held hygrometer.
Decent hygrometers can be purchased at stores like Radio Shack or any place that sells weather instruments. If you decide to monitor your indoor humidity, do so on a daily basis and begin to keep a log. Take readings in the center of a hallway or some location slightly removed from the places where humidity will be naturally high like a kitchen, bathroom or laundry area. Take readings at the same time each day if at all possible.
Be sure to write down the outdoor temperature on the log beside each indoor humidity reading. It would also be helpful to write down the degree of condensation on windows or lack thereof with each reading.
If you do have condensation problems, a humidity log such as this will be very helpful in trying to pinpoint the problem.
Replacement Windows
If you want minimal condensation on replacement windows, then you must buy ones that are of the highest quality. Quality can be measured fairly easily. I happen to be a huge fan of independent testing and certification. Third party labs and associations can create strict manufacturing guidelines that ensure you are getting a great window that will minimize condensation.
Continue to read about the different certified programs and the companies that make windows that meet or exceed the strict guidelines. If you buy certified windows from a top-notch company, you should be a very happy camper!
