Condensation In Windows
Now that the serious cold weather is here, the complaints about moisture on windows start. "There isn't enough caulking, they are leaking air, they don't insulate enough" - I could go on and on.
I say, your house is too humid, and then the response is " but I NEED the humidity, the house Is too dry so I have to use a humidifier."
When I go to my clients' homes to inspect their new windows and what they are complaining about, what I see amazes me. First, I walk into the house and the humidity hits me and my glasses fog up. I then proceed to the problematic windows which are usually in a bedroom or a kitchen. These are the two rooms that carry the most humidity.
I then look at the bedroom window, but first I have to lift a layer of blackout blinds and in some cases, another set of heavy decorative window treatments. After lifting them I'm asked "why do I have so much water and ice on the bottom of my windows?"
This is when I realize what a lack of understanding most people have about thermal windows. I will now try to explain how they work.
Most thermal glass has two layers, one on the inside and one on the outside. There is an airspace between the panes filled with argon gas. If you want your high performance thermal windows to do their job you must understand this: The exterior glass is freezing cold, while the inside glass is warm from the heat of the room. The airspace acts is a buffer zone between the two panes separating the two extreme temperatures. By keeping the blinds down, you are preventing the glass on the inside from staying warm and the exterior temperature then takes over and it freezes.
With an ice cold window pane behind your blinds, any humidity trapped there turns to water and then freezes. Bingo! Condensation.
Depending on how high the level of humidity is in your home you can even have plenty of moisture on windows with no blinds. We create humidity in many ways, especially in bedrooms where there is a bathroom and shower plus people sleeping all night. The worst culprit is the humidifier.
So what can you do to limit condensation in windows? First of all, keep your blinds up as much as possible allowing the warm air to circulate around the window.
Keep the level of humidity as low as you can live with.
Try to vent the moist air created by bathrooms, clothes driers and vents over stoves - outside.
And please remember one thing, a thermal window does not insulate your home the same way a wall does.