Humidity, Condensation, and Your Home

At one point or another you may have noticed water beading up on the inside of your windows, just like it does on your mirror after you take a shower or your car when you first get in in the winter. The question often posed is what causes condensation on my windows and how can I prevent it?

To answer this we first have to understand what humidity is and where it comes from. Humidity explained in its simplest form is moisture in the air. In your home moisture gets in the air from a wide variety of sources every day! Cooking, showers, laundry, and even breathing are some of the major contributing factors to humidity in your home. The humidity or moisture in your air is measured as a % and can fluctuate substantially as the seasons change.

Condensation is the result of warm, humid air meeting cold air. As glass is the easiest place to spot condensation your windows tend to be where you first notice it, though it can occur on appliances and walls as well! In Minnesota we see this most often during the winter months, with the condensation forming on the inside of the window. It can happen in the summer months when it is humid outside and cold inside, but it is not as common.

Humidity in the air is good-to an extent. Too much humidity in your air leads to condensation issues, mold, and even rotting of building materials! So how do you know how much you have!? A humidity meter is inexpensive and can be purchased at most home improvement stores and some big retailers. Simply place it in your home, check it a few times a day and see what level your home is at.

The humidity in your home should follow the data below:

Temperature:    Humidity %

-20F                       15-20%

-10F                       15-20%

0F                           20-25%

10F                         25-30%

20+F                      30-35%

If your humidity level is above the recommended amount there are a few measures you can take to lower the humidity levels. The first is to increase ventilation. Be sure to have your bath fan on when you take a shower, open doors and windows from time to time, vent clothes dryers outside, and keep your attic vents open. If you have a humidifier, adjust its settings accordingly as the temperature outside changes. Taking the time to control your humidity now can save you time and headaches later!