How to Stop Window Condensation: Expert Tips
Professional Blog

How to Stop Window Condensation: Expert Tips

Updated: 02.02.2025 by Argo Glass & Windows

WHY DO THE WINDOWS FOG UP?

The transparency of glass unit sections often diminishes, getting older, particularly if the double-glazed mechanisms are poorly maintained. A decrease in the transparency of window panes is often observed in rooms where old double-glazed glass units are still used. If something like this happened to the windshield of a car, you would unequivocally regard the resulting haze as dirt and promptly remove it with a chemical cleaner.

But with the windows in the room, not everything is so simple - the reduced transparency is most likely due to one of thе reasons:

  • Elevated degree of dampness inside: In the cold season, humid and warm air inside encounters the cooler surfaces outside, creating dew and a foggy appearance.It is too humid inside the room - in the cold season, the glass turns out to be cold enough for excess moisture to condense on the window. More about managing indoor humidity from the Environmental Protection Agency (EPA).
  • Outside humidity infiltration: Once seals surrounding the pane glass degrade, outside dampness may appear between two panes, leading to persistent blurring that is impossible to wipe. Outside the room is too humid - but then "fog" is formed not from the inside, but in between glass panes
  • Poor sealing: With age linings break, permitting dampness and air to find their way into the glass unit, rendering cleaning ineffective and trapping water droplets. You can no longer rely on the used sealant - it is worn out, and therefore condensation settles on the surface of the glass in the inner chamber, where it cannot even be wiped off.
  • Degree disparities: The temperature difference inside and outside usually affects much. Especially, single-pane windows are vulnerable because of low insulation compared to progressive designs. Understanding all the underlying factors enables homeowners to take effective action and implement preventive measures.

Different Types of Windows

Wood Windows

Natural Look with Maintenance Needs

Wooden frames are valued for their natural look and insulation properties. However, they can be more susceptible to moisture if not properly sealed or maintained. This can speed up the appearance of fogging, especially when the wood swells or cracks.

PVC (Vinyl) Windows

Durability and Cost-Effectiveness

PVC windows are popular for their durability and cost-effectiveness. They are less likely to suffer from moisture-related expansion, but poor installation or damaged seals can still lead to fogging. Ensuring proper installation is key to preserving their longevity.

Aluminum Windows

Key Features

Aluminum frames are strong and lightweight. Yet, they conduct heat more readily, which may create a higher risk of condensation if the interior and exterior temperatures differ significantly. Quality insulation or a thermal break in the frame can help prevent fogging.

  • Why are my windows foggy?

    Usually because of high humidity inside and temperature differences, or due to a compromised seal (e.g., worn-out sealant, damaged glass).
  • Foggy window repair near me: Should I look for a local service?

    Yes. If you want a prompt fix and guaranteed work quality, hiring a local professional is wise. ARGO glass & windows provides services in Illinois, Wisconsin, and North Carolina

STAGES OF FOGGING UP GLASS UNITS

There are 2 solutions to fix broken seals:

  1. Defogging is the process of drilling tiny holes in the outside pane which allows the space to dry out properly before closing them up. This treatment process removes the water between glass panes and it might take about up to 2 month depending on the amount of moisture inside. With this procedure your window loses it energy efficiency because the argon gas can’t be pumped in again and the chances are very high that moisture will appear again in near future.
  2. Argo Glass & Windows believes glass replacement is the best solution and cost effective service to fix broken seal. This involves carefully removing the existing panes, cleaning the frame, and installing new glass in the opening. This option is typically the most cost-effective and reasonable solution to a failed glass seal.

With using only best quality materials Argo Glass & Windows provide long term warranty for any services that we provide. Call now for more details and take advantage of free estimates

Where is the problem observed?

The most common problem with fogging on the outside or inside is when the window is glazed with just one layer of glass, which is rare. This is because the difference in temperature and humidity outside and indoors is very large, and there is no smooth transition between the two zones - one glass cannot provide smooth changes in conditions. By the same logic, with double glazing, fogging is more likely to occur inside the chamber, rather than outside or inside.

It is not difficult to check what kind of problem you are facing: you need to try to wipe the window, first inside, and then outside. If this did not work, it means that condensation accumulates between the glasses, and this problem cannot be solved without replacing the glass unit.

  • How to clean double pane windows from the inside?

    If moisture is in the air gap between panes, basic cleaning won’t help — you need to address the seal. If it’s just on the inside surface (the side facing the room), standard window cleaning products will do.

BRIEF DIY GUIDE (What You Can Do Yourself)

In most cases, “foggy windows” result from high indoor humidity, poor window seal (worn-out sealant), or differences in temperature inside and outside. Sometimes, you can fix the issue by yourself, but very often you need professional help to restore the normal transparency and energy efficiency of your windows. Below, you will find detailed explanations of why double-pane windows fog up and various ways to solve the problem — from basic DIY steps to complete window replacement.

Warm up the windows or use anti-fog solutions

If you see “fog” on the glass, try gently warming it with a hair dryer or a portable heater to temporarily remove the condensation.

For an extra effect, use anti-fog sprays (commonly used for car windows and mirrors). Follow the instructions on the product’s label.

Seal minor cracks or micro-damage

If there is a small crack, you can temporarily seal it with clear silicone on both sides to prevent moisture from seeping in.

Keep in mind, this does not fully restore the window’s seal, but it may delay further damage until a proper repair.

Ventilate and reduce indoor humidity

Use exhaust fans in kitchens and bathrooms, run a dehumidifier, and open windows/doors to improve airflow.

The lower the humidity, the less likely water vapor will settle inside the window unit.

Clean the inside surface (if accessible)

Sometimes moisture is on the inner surface (facing the room) rather than between the panes. Wiping it with a soft cloth and standard window cleaners can help.

However, if condensation is truly between the panes, simple wiping will not solve the issue.

Important

If the core issue is a serious seal failure (loss of inert gas, damaged pane, worn-out sealant), DIY fixes only provide a temporary solution. In such cases, contact professionals.

CAUSES OF CONDENSATE AND METHODS OF DEALING WITH IT

If you installed new windows with double glazing, but after a while you found moisture accumulations on the inside or outside of the window, then this is a sure sign of the presence of leaking sections around the perimeter of the structure. It so happens that the window itself is leaky. This is manifested due to factory defects or deformation of the glass, in this case double. The call of the master will be inexpensive, but you can find out exactly why it is condensation on windows with double glazing. When the reason is determined, it remains only to eliminate the fault, which will restore the reference technical condition of the structure.

Evaporation

SEALANT & REPLACEMENT

If the inert gas evaporates, then because of this, the tightness of the window will immediately be broken. This will cause condensation to form. It happens that the sealant is of poor quality or incorrectly applied at the factory. Because of this, inert gas escapes from the glass unit, and due to temperature differences in the room and condensate accumulates outside the window. In this case, there will be no point in repairing the glass unit, since it is much easier to carry out its complex replacement. This procedure can be done in a few hours, and cash costs will be insignificant.

Damage

SEALING VS. REPLACEMENT

Another reason for fogging double glazed windows is damage to one of the glass panes. In fact, there will also be a depressurization of the glass. You can restore a damaged place by sealing a crack, for example, but this is a temporary measure that cannot protect from condensation on windows, because the inert gas that is in the cavity between the panes will evaporate immediately and the structure can no longer work in normal mode. If such problems occur, only the replacement of the glass unit can also help. In order to avoid mistakes in the course of diagnostic work, you should contact the experienced professionals

Hardware

ACCESSORIES & SEALING

Bad hardware can also cause windows to mist up. When their shutters loosely adjoin the window frame, the air from the street penetrates inside the room, causing the appearance of condensate. You cannot worry about the fact that you have to change the window, as it is enough just to replace the weatherstip. Such problems can cause poor-quality weatherstip.

They can also be replaced in just a few hours by contacting a specialized company. In any case, the fogging of the glass is associated with its depressurization. In any case, it will be possible to solve this problem only after a complete replacement of a damaged glass unit with a new analogue, in which quality there will be no reason to doubt. As you can see, even double-glazed windows can mop up, but there is nothing critical in this phenomenon; the problem can be fixed in a short time if the appropriate measures are taken immediately.

  • Can fogged windows be repaired?

    Modern windows are striking in their durability and good quality, but in practice and with them there are problems. Condensation or condensation is one of the most common problems related to windows from different manufacturers. Even products of famous brands are not without flaws, and sometimes even high-quality windows cause inconvenience due to violations of their installation technology. You can have full confidence that the windows will serve for a long time, if timely carry out preventive and diagnostic work. The appearance of fogging on the windows is the first sign that not everything is all right with them. This can be determined by various signs. For example, windows from sweat depressurization sweat - it happens most often. There may also be poor indoor air circulation, a large temperature difference in the room and outside. To get rid of window fogging, you first need to determine the cause of this phenomenon.
  • Fix it myself or hire a pro — which is cheaper?

    Poor hardware is another cause of fogging. If the sash windows are not tightly closed, then there will be drafts, provoking fogging. You can get rid of the problem by installing a new, better hardware. To do this, you should contact a specialized company and order this service. Fortunately, it is inexpensive, and accessories in such companies are always available from different manufacturers, so there will be no problem with the choice. If you are not a specialist in modern windows, then you should call specialists for diagnostics. This will save you money and time. The main thing is also that the new seals should be of decent quality, and no mistakes should be made during the installation, otherwise condensation will continue to form on the panes.

Can you get condensation out of double glazing?

It often happens that even after installing new windows, problems arise with them.

Misting or condensation is not uncommon, but there are many reasons for it to appear. Windows from famous brands can have a guarantee of several decades, but even in this case, they serve for a long time without causing problems.

If the technology of their installation has been violated, and a factory defect has manifested itself, then fogging will appear. It is worth noting that most often double-glazed windows are installed in the windows. They are reliable and durable enough. Between the glass is inert gas in a sealed capsule of two glasses. This is necessary in order to avoid fogging. However, sometimes they appear even on this type of glass. Many people believe that the choice in favor of such a design will completely relieve them from the appearance of condensate, but in reality this is far from being the case. Today we will understand what causes the windows with double glazing to mist over.

Useful Prevention Tips

  • Monitor indoor humidity:
    If the indoor humidity stays above 60%, condensation risk is higher.
  • Regularly check seals:
    Over time, sealants degrade, causing window seal failure.
  • Watch out for micro-cracks:
    Don’t wait until a minor crack becomes a major problem.
  • Invest in quality windows:
    nstalling a high-quality window system can solve fog issues for many years rather than repeatedly patching cheaper ones.

  • Condensation between window panes: what should I do?

    Look for cracks, worn-out sealant, or frame damage. If found, you may need to replace the seal or the entire IGU. As a temporary fix, some users drill small holes to remove moisture, but that reduces the window’s energy efficiency
  • How to fix foggy windows quickly?

    You can warm the glass, reduce indoor humidity (dehumidifier), and check the seals. But if the seal is broken, you might need to replace the IGU or consult a specialist. If you see that the window is fogging, you need to start looking for the cause of this phenomenon. Most often the problem lies in the depressurization of the structure. For example, sealing rubber bands may crack and air from the street will begin to penetrate inside the house. In this case, condensate will accumulate on the glass. In this situation, only the replacement of sealing gum will help. We recommend calling specialists from time to time to assess the condition of the windows, and if necessary, replace those or other structural elements. This approach to the care of the windows will significantly extend their operational life! ARGO glass & windows repair windows and solve fogging.
  • How to get rid of foggy windows?

    Basic steps (hair dryer, anti-fog solutions) may work for minor issues. For serious leaks or worn-out components, replacing the glass unit or hardware is more reliable.

Key Takeaways

  • Foggy windows often happen because of condensation (high humidity, temperature differences, or a broken seal).
  • DIY methods (warming the panes, reducing humidity, temporarily sealing small cracks) are typically stopgap solutions.
  • Professional repair (replacement of the glass unit, sealant, or hardware) is essential if the seal is severely compromised.
  • ARGO glass & windows (or another reputable company) can handle complex cases that DIY alone cannot fix.
  • Regular maintenance and normal indoor humidity levels are the best ways to prevent windows from fogging up again.

ARGO GLASS & WINDOWS SERVICES

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