by: Brian Olkiewicz

As the seasons change from fall to winter, you may notice small beads of moisture on the glass of your windows and doors. In most cases, the build up of the water on the glass is known as condensation. As the temperature on the outside falls and the need to keep our homes warm and toasty on the inside. Combined with the forced air from the furnace which diminishes humidity in the home, so what do we do, turn up the humidifier. This the main reason you may find a collection of liquid in the shape of a smiley face on your window panes. Moisture will settle on the coldest surface which in most homes is the glass in your windows and doors. What can you do about condensation, here a few possible solutions. Check the levels of the relative humidity in your home, as the temperature outside falls so should the moisture on the inside. For example, if the outside air temperature is 10 degrees Fahrenheit, the RH in your home should have a maximum level of 35%.  Another simple fix is leaving the window coverings (shades or blinds) slightly open at night, this will allow warm air to reach the glass surface of the window. One last idea is to occasionally crack open a window or two for a short period of time. Outdoor winter air is much drier and will help reduce the humidity indoors. If you have windows with two panes of glass, also knows as Insulating Glass, and this phenomenon occurs, most likely it is not a defective window. 

For additional technical information, check out the University of Minnesota research on this subject matter.