loader image


Window condensation: What causes it and how to defog

When you wake up in the winters and remove your curtains to have a look outside the windows, but you can’t because of the fogged and frosted windows, it’s not a good feeling. The aesthetic value of your home is one among the many concerns that might bother you and not only in the winters but summers also In the summer days, when it’s all heated up outside, and your AC is blasting at its best inside the home, you can see condensed vapor on the exterior side of your windows.

Fogging or condensation on your windows is a sign that there is an increased level of humidity which is a health concern, especially for people with chronic allergies or respiratory problems.

Can fogging be prevented, or can your windows be defogged effectively?

Definitely, yes. You can deal with fogged windows, and we will guide you with ‘why’ and ‘how to.’ Why do house windows fog up?
‘Insulation’ is the basic purpose of installing windows, that is, to prevent the exchange of heat between two regions. While in the winters, they keep the inside of your home warmer than outside, in the summers, they keep inside cooler.

However, there is still an amount of heat exchange as windows are not perfect insulators.
There are plenty of reasons for foggy windows. But to find out the reason behind foggy windows, you must look out for the place where the fog is settling.

Is the fog taking place at the interior side of your windows, exterior, or inside the panes of glass? Let’s have a look at each of the three conditions to understand why your windows are fogging up.

  • Exterior condensation is the result of the high temperature outside and the lower temperature inside the home. It causes the warmer air to condense outside the windows when it comes in contact with the cooler windows (due to your interior cooling system), and the air loses its moisture at the windows. This is very similar to water droplets forming in your cold drink bottle when you take it out of the refrigerator. When there is an abrupt difference in exterior and interior temperatures, condensation builds up on the cooler side. But you might take note here that the exterior humidity is high in this particular condition.
  • Interior fogging occurs when the heating system inside your home in winter is operating at a comfortable customized rate. There is heavy cold outside, but the air inside your home is warmer than the air outside due to the inside heating system.
  • This temperature difference causes the moisture present in your home’s warm air to settle down on the windows as the air meets the cold windows( despite your well-working heating system, when you touch the glass of your windows in the winter, you feel a cold sensation).
  • If the moisture level inside your home is high, many of these water droplets are condensed on your windows and visible as fog. Sometimes, you might get tired of wiping the windows to remove the fog, but a while later, it again sets in.
  • We will discuss how to get rid of this problem later in this article.
  • Fogging between the panes of glass can occur in any insulating glass window. Sometimes the seals break down, especially in older windows, and it makes an easy way for moisture to enter. This moisture is trapped by the desiccant material present, and later it reaches saturation level; that is, there is no more space for moisture to be absorbed.

This is visible as fogging inside the window glass, and given extremely cold temperatures, the moisture present inside the panes of the glass can also frost. The time taken for the fog to settle inside the glass varies, depending upon the sealant, desiccant material, design of the windows, insulating glass, and local conditions. Once there is a seal failure, the sun rays cause further damage, and also the fog inside the windows is more visible when the sun shines through the glass.

By now, you might have observed that the major reason for fog building on the interior side of your windows and inside the glass windows is due to high levels of humidity.

We are going to suggest effective solutions, but before that, you might be wondering if fogging is a serious problem to worry about. Well, know for yourself here.
Should I be worried about foggy windows?

Fog or condensation on the windows and inside the windows is bad news.

While it may give rise to many problems, fogging up is self-indicative of glass failure or seal failure. It might also indicate bad installation of windows. While window replacement can be a costly process, but there’s a good chance repairing can solve your problem, and it is a cost-effective option.

Here are the reasons why fog or condensation might concern you.

  • Mold and mildew are the main problems caused by window condensation. It can result in damage and stain on drywall. It ruins your room’s appearance as black dots are formed around the windows and on the walls in the room.

    Left unchecked, it can also damage your furniture and wardrobe.

  • Exposure to a foggy or damp environment can cause health issues like throat irritation, respiratory problems, skin irritation, etc. Mold exposure can cause lung infection in people with chronic lung illness if they have mold allergies.
  • It can add up to home renovation and repair costs if ignored.
  • It reduces the energy efficiency of your home as the sunlight, which could help in heating the home interiors in the colder months, is used up in evaporating the fog collection on and inside the windows. This again puts the moisture back inside the home with increased levels.

Fogged-up windows are something you can’t afford to ignore. So let’s get on with how to fix it!

How to fix your fogging-up windows?
By now, you must be eager to know quick and workable solutions for fogged-up windows. So we are sharing here some effective tips and solutions, which include both preventive and curative measures.

  1. Open your windows
    This is the simplest idea to allow the moisture trapped inside your home out and let the drier air outside balance the warmer air inside. This prevents the moisture inside from settling on the window glasses, and you also get fresh air.
  2. Exhaust fans
    Lots of the moisture present inside your home comes from the kitchen and bathroom. And those are essentials you can’t avoid, so using bathroom and kitchen fans is a good idea to remove the moisture from the inside.
  3. Buy a dehumidifier
    Yes, it costs a bit higher, but you can’t deny that it is an easy and portable way to get rid of moisture inside your home. In some dehumidifiers, you don’t even have to bother about turning them on and off as they automatically remove the moisture once it reaches the set level.
  4. Moisture eliminator
    It is a cheaper solution to soak up extra moisture. Moisture eliminators come in buckets or bags, so you can set them in places like the kitchen or bathroom that release relatively high moisture.
  5. Blower
    Switch on your blower fan if you have an already running heater so that the air moves around and dries up the window condensation.
  6. Move your houseplants
    The water you are adding to the plants is simply raising the moisture inside your home. So keeping them in a different place becomes important to help reduce fogging.
  7. Window Insulation kits
    Not only it blocks moisture from coming in contact with cold glass, but also it keeps your home warmer. This is an energy-efficient and bank-friendly way as it reduces your cooling and heating bills.
  8. Clean your windows
    Clean your glasses to stop the build-up of haze caused due to greasy substances or condensation.
  9. Renewal of sealant
    Problems with the sealed unit in the windows can cause condensation or fog up. Sometimes the sealant between the glass and the frame fails( mostly in older windows) and needs to be replaced or resealed.
  10. Repair
    Sometimes moisture sets inside the double-glazed window even if the seal is intact. What we do is drill a few small holes in the outer pane and let the moisture out. Further, the dry air from the outside is pumped back to ensure the insulation and resealing are done. A repair can save you from costly replacement until necessary.
  11. Replacement
    Depending upon the type, age, and damage of the windows, the glass units, or sometimes, the whole window is replaced.
    This does sound expensive but saves your electricity bills.

Our expert technicians at Chosen Wood Window Maintenance are just a call away to help you out if your window problems have gone beyond preventive tips.
Also, we provide you with a prior assessment and estimation to help save your maintenance budget. We are your all-rounder window physicians, foggy or not!