MARCH BLOG: Why does condensation form at windows?

East Bay Indoor Environmental

The indoors is OUR Environment!

March Newsletter:

Domestic Hygiene Lesson 1: “Why does condensation form at windows?”

Hello All!

East Bay Indoor Environmental is your resource for all matters of creating a healthier indoor environment. Like every month, we strive to give our readers a kernel or two of information to improve and maintain a healthy live/work space. As we get closer to spring time and our impending spring clean, this month we’ll begin our domestic hygiene component. We received a flood of calls last month about condensation at the windows. How it forms, why, and most importantly what is the impact to our indoor environment. With help from our friends at Stanek windows we’ll help you to understand window condensation.

 What causes interior window condensation?

Interior window condensation is caused by excessive moisture in the unit, and it often occurs in the winter when the warm air inside the house condenses on the cold windows. Exterior window condensation is simply dew and occurs when the window is colder than the dew point. Interior condensation, or the condensation that occurs on the inside of your windows, is the most common type, and there are a variety of things you can do to remedy the problem.

Open Your Windows

If it isn’t too cold, you can open your windows. This will release some of the warm, moist air that is trapped in the house. Even in the winter. Buildings are sophisticated eco-systems, they need to breathe. A small gap in the window should not create a water intrusion.

Buy a Moisture Eliminator

If you suspect that there is excess moisture in certain areas of your home, you can purchase a moisture eliminating product, such as DampRid. These products often come in buckets that you can set on your floor or in bags that you can hang, typically in your closet. You can use these products in your bathrooms, kitchen, or closets (where they will also help protect your clothing from moisture damage), and they will remove excess moisture from the air. Opening a large box of baking soda and placing it (do not pour it out) it in dark corners of closets and under cabinets also helps to absorb moisture and odors similar to a refrigerator.

Turn Down the Humidifier

You might notice condensation in your bathroom, kitchen, or nursery. In the nursery this problem is often caused by a humidifier, which many new parents use. If you use a humidifier in any part of your home (including the humidifier that works with some furnaces), you can try turning it down. As a result, the humidifier will release less moisture into the air, which will hopefully reduce condensation.

Bathroom and Kitchen Fans or Windows

Use your bathroom and kitchen fans every time you cook or shower. Showering and cooking releases a lot of moisture into the air, and sometimes this moisture cannot escape from your house easily. The exhaust fans in your kitchen and your bathroom help remove this moisture from the air. You want to run the fans for about 15 to 20 minutes after you shower or cook. If you don't have a fan, open the window.

Circulate the Air

Circulating the air can also help reduce the condensation on your windows. So, use your ceiling fans even in the winter. You want the fans to rotate in a clockwise direction to push warm air off of the ceiling back down to the floor. Add inexpensive fans if ceiling fans are not in the unit.

Raise the Temperature

Raising the temperature of the windows will reduce the condensation on them. Condensation occurs when warm air hits a cold surface (the window). Think about taking a cold drink out of your fridge on a warm day. The surface of the can immediately gets wet. In order to raise the temperature of your windows, you can raise the temperature of the house slightly. You can also use blinds, curtains, or drapes to raise the window temperature as well.

Add Weather Stripping

Adding weather stripping to your windows can help keep warm air from leaving your home. This can help reduce condensation if you’re using storm windows during the winter months. Weather stripping also helps make your home more energy efficient.

Move Your Plants

Plants release moisture into the air, so if you have a number of plants by your windows, moving them to a different place can help reduce condensation on the windows.

Buy a Dehumidifier

Purchasing a dehumidifier is an easy, expensive way, to remove the moisture in your home. If a full size dehumidifier, which is usually $200 to $300, is too expensive for you, the mini dehumidifiers don’t seem strong enough from our observations is the field. Some dehumidifiers will need to be turned on and off, while others will come on automatically when the humidity level in the home reaches a certain point. These units are becoming more and more common in areas with low average humidity as a result of the increase in energy efficient, multi-level, housing developments.

Should I clean the window and surrounding area?

Yes. Mix a 3:1 ratio of white (distilled) vinegar to water inside a spray bottle (32 ounce or similar). Spray the affected area and wipe clean. Repeat as necessary.

What about condensation between window panes

If you see condensation between window panes? Try Cleaning the Windows! If you think that you have condensation between the windows, be sure to clean them off first. The haziness might in fact be caused by condensation or it may be caused by a buildup of something, such as a cleaning product or grease (in the kitchen).

Have Patience

As the sun warms up the windows, the condensation will evaporate. Just like the dew evaporates off of your car and your lawn, it will evaporate off your windows as well.

If worse…

Contact a reputable window professional in your area.

All in all condensation at the windows can occur. It is rarely an indication of mold growth or hazard to otherwise healthy human beings. If anything, it’s an indicator of climate change, age or style of window, and time of year. If actual water forms on windows sills, floors, or leaks develop, picture or video the occurrence and forward to your property manager without delay if you are an occupant. If you are the owner contact a reputable window professional in your area


Want to do some research?

The Environmental Protection Agency

Stanek Windows

If you’re curious about your indoors, send us a question and we may select your topic for our next newsletter!