How to stop condensation on inside of windows

You’ve probably noticed that when it’s cold outdoors, you often get frost or condensation on your windows indoors. Perhaps you’re even tired of water accumulating on the inside of your glass and eventually dripping down and causing water stains and damage to your sills or floor. If you’re really lucky, and you have a thirsty cat, he or she will let you know how bad your window condensation problem is by licking the moisture off the glass. Yuck! Let’s take a look on how to combat this problem once and for all.

Condensation on inside of windows
What causes water condensation on your panes and how do we stop it? We know that when your house is warm, it means the air is warm. Warmer air holds more moisture than cooler air. When the warm air meets a cold surface, water can condense and settle onto it. And just like a cloud, too much moisture settling leads to water accumulation that needs to go somewhere, i.e. water droplets inside your home. This isn’t a good thing indoors, unless you’re washing dishes or taking a shower! So, we need to take a look at how to control this warmer air and maybe also how to control the colder window surfaces.

How to stop condensation on windows
This article talks about some no-cost ways to help your wet window problem. Some tips may not apply or work for your situation, however. Here are some solutions that will at least help, if not, solve your problem:

Solution #1 (Good)

Rain-X Glass Anti-Fog This long-time, trusted product has worked to stop car windows and bathroom mirrors from fogging up. The insides of your home windows where heavy fogging occurs aren’t much different. Simply wipe on the window glass until it disappears. Reapply as needed. May not work as well in extreme cold or humid conditions. Amazon sells for cheap – get 2-3 bottles depending on how many windows you have!

Solution #2 (Better)

Window Film Kit to help with condensation When applied to the inside of your windows this 100% see-through film can keep glass surfaces free of condensation (it blocks warmer/humid indoor air from reaching the cold glass and fogging it up). What’s more is the film obviously helps keep your house warmer too in addition to aiding condensation build-up. This stuff goes on perfectly clear. Check out the reviews at Amazon. This product is also eligible for a tax credit since it helps to weatherize your home. You might also try monitoring the humidity and dew-point levels in your house with a Thermo-Hygrometer – a great little gadget that tells you the current humidity level indoors.

Solution #3 (Best)

A dehumidifier placed in the room will stop window condensation If you really want to eliminate your problem, place a dehumidifier in the room (preferably by the offending windows). This portable unit will remove moisture from the air to the point that it won’t “stick” to your windows any more. These guys are quiet, energy efficient that will last season after season – they are well worth the investment. Here’s a very popular model at Amazon.com

Window condensation is most likely to occur during colder winter (or spring and autumn) months and usually in the morning hours when temperatures are cooler. If your window fog is temporary, such as only first thing the morning or during a large gathering of people, your fix is usually just to wait it out, unless the condensation starts leaking off the glass.

The best way to disrupt the warm, moist air from moving to and sticking to your cool windows is to get air moving. If it’s not too cold outdoors, opening the house up (cracking doors or windows ever so slightly) can be the solution. This allows the colder, drier air from outside to mix with the warmer air around your windows. In older homes that aren’t sealed as well, this happens already, as cooler air from the outside sneaks in around windows. If you’re getting window condensation, it just means your house is sealed relatively well and energy efficient. You probably have newer or double-glazed windows. Many times though, it’s best to just turn the house fan on in your forced-air system to move the air around. If you’re already running a furnace/heater though, and the blower is running, flip your switch to continuously run the fan. That means, air will be moving even when heat isn’t coming out. Be sure to have curtains open so the circulating air can move around and help dry up the window condensation faster. If you have a longer-term window condensation problem, then you may need to add a dehumidifier to your HVAC system or get a less expensive portable one.

Before getting a dehumidifier though, let’s look at how to decrease the overall humidity in your home. It’s obvious that showers, baths and cooking creates a lot of moisture in your home. Always be sure to run the exhaust fan to eliminate moisture. Here are some other causes of moisture in your home that you may want to think about changing or addressing:

• Houseplants: the more you have, the more humidity
• Dryer vent: make sure it goes outdoors and is sealed well
• Wet or damp laundry: do not hang to dry indoors
• Fish tanks: cover up aquariums to reduce humidity
• Stop breathing: humans expel a lot of moisture while breathing…okay, maybe you shouldn’t use this tactic!
• Basement floors/walls: seal these surfaces by painting or coating with concrete sealer to help keep moisture out and raising your relative humidity in your house
• Rain: inspect that your gutters and drains are all diverting water away from the house; i.e., keep water away from your foundation

Once we can get air circulating and reduce the humidity levels, the next thing to look at is keeping the surface of those windows as warm as possible to further reduce the formation of condensation. The obvious one, although expensive, is to install double or dual-glazed windows. You can also add storm windows to the outside. Both of these solutions help keep inside glass surfaces warm. If installing new windows, be sure there is good insulation in your window framing or the walls around where they are. The more cold air coming from around them, the colder your new, “warm” windows can become, which leads to water condensing on the glass or sash. To prioritize when considering budget, try installing storm windows just on the north side (coolest side) of the house. Or, if you live in a windy climate install these on the opposite side of the house from where the wind comes from.