why do we get condensation on the windows

Get a small, anything will do, less than $10 works well
If you have up to %50-%55, you should not get condensation on double pan window. I had single pan that was every morning totally wet, I could fill a glass with the amount of condensation on that window. Replaced it with double pan and now there might only be a bit condensation on the lowest half inch of the window (lower -> colder). the difference in temperature between the inside and outside air. If you keep your house warmer, and that in turns heats the inside surface of the window, you will get less condensation. That is why people explained that if you do not cover your window with curtains you are less likely to get condensation. That is because the inner surface of the window now gets heated by the inside air.

When you cover the window, you are increasing the insulation for the house (good thing) but that is because you are no longer hearting the inner window surface. So, the inner window gets colder. When it gets colder, the air in the room comes in contact with it and cools down. When Air cools down, this is where it is important to understand relative humidly. The humidity you measure is relative. Relative to the air volume. I hope everyone remembers that the volume of the air changes as a function of its temperature. So, if you measure 60% humidity at 70 Degrees, you will see that when the air cools down to lets say 50 degrees the humidity will rise (don't know the formula, but lets say it can rise to 75%).

So why do you get condensation? because the surface of the window is cold (either draft, it being single pane or badly insulated double pane, or it is simply cold in your house) And because when the air in the room reaches that, its relative humidity approaches 100% and you get water. Things you can do 1. lower humidity (measure it first) by ventilating the house when outside humidity is lower 2. keep humidity low by using external air fans when showering and cooking 3. improve the windows insulation (but you said it is new, so I guess you tried that. unless you bought a single pan window. ) 4. Improve window insulation by using (I tried it, it works! ) If you find that your in-house humidity is high (70-80%) all the time and you cannot get it down. we have the same problem (-: I wish I knew what to do about that.

When the temp gets around 35 or below, my windows sweat really bad. It freezes around the frame and I have to scrape it off. Our home is 11 years old, but the windows have done this since it was new. My husband says it is the gas fireplace that we use that does it. I read that too much humidity would cause it, would a dehumidifier help? I have to go around every day and dry the windows. Can you help? Carol, We get a lot of questions about windows sweating in the winter. HereБs whatБs happening and why.

When air warms, it expands which allows it to hold more moisture. As it cools down, it contracts until it reaches the saturation point and releases this excess water in the form of condensation. Common daily activities in your homeБsuch as cooking, showering, using unvented gas heat, and even breathingБadd moisture to the air. When this warm humid air comes in contact with cold window glass, it cools and condenses. To reduce this problem you need to either lower the amount of moisture in the air inside your home, or prevent it from coming in contact with cold surfaces. Here are some suggestions that might help: Run a vent fan in the bathroom when you shower or bath, and leave it on for 15 minutes afterward.

Be sure it is vented to the outside and has a high enough capacity for the room. Also, be sure there is a large enough gap under the bathroom door to allow air to enter. Vent gas fireplaces, or limit their use, and donБt use older unvented gas space heaters. Cut down on cooking that produces excess steam. Lower your thermostat to 66б-68б F. Be sure your clothes dryer is vented properly to the outside. Seal up any cracks around windows. Replace older single pane windows with double or triple pane vinyl ones (avoid metal window frames since they conduct cold), or add storm windows to the outside of your house. If you are still having problems, consider installing a dehumidifier.