How to Clear Condensation from the Inside of Double Glazing

Condensation in Double Glazing


Double glazing is a popular window option for many homeowners. It consists of two panes of glass with a layer of air or gas sealed between them. This design helps to insulate the home, reduce noise, and improve energy efficiency. However, one common issue that can arise with double glazing is condensation forming on the inside of the window.

What is double glazing?

Double Glazing

Double glazing refers to a window unit made up of two panes of glass. These panes are separated by a spacer and sealed together to create an airtight unit. The space between the panes is often filled with air or an inert gas like argon to enhance insulation properties.

Related: Best Glass for Double Glazing

The problem of condensation in double glazing

Condensation occurs when warm, humid air comes into contact with a cold surface. In the case of double glazing, this often happens when the inside pane of glass becomes significantly colder than the air inside the room. Moisture in the air condenses on the cold glass, leading to the formation of water droplets or a misty film.

Causes of Condensation in Double Glazing

Condensation in Double Glazing

Several factors can contribute to the development of condensation in double glazing. Understanding these causes can help you identify the source of the problem and take appropriate steps to address it.


High humidity levels inside the home

One of the primary causes of condensation in double glazing is high humidity levels within the home. Activities like cooking, showering, and drying laundry can release significant amounts of moisture into the air. If this moisture is not properly ventilated, it can lead to condensation on cold surfaces like windows.

Poor ventilation

Inadequate ventilation can exacerbate humidity issues and increase the likelihood of condensation in double glazing forming. If your home lacks proper ventilation, moist air can become trapped inside, raising the overall humidity levels and leading to condensation on your double glazing.

Temperature differences between inside and outside

Condensation is more likely to occur when there is a significant difference between the temperature inside your home and the temperature outside. During cold weather, the outer pane of glass in your double glazing will be colder than the inner pane. If the inside pane cools down enough, moisture in the warm indoor air will condense on its surface.

Identifying Condensation in Double Glazing

Identifying Condensation in Double Glazing

Before you can address the issue of condensation, it’s essential to make sure that what you’re seeing is indeed condensation and not another problem, such as a leak.

Signs of condensation in Double Glazing

Condensation on double glazing typically appears as water droplets or a fine mist on the inside of the window pane. You may notice that the condensation is more pronounced around the edges of the glass or in the corners of the window frame.

Differentiating between condensation and leaks

To distinguish between condensation and a leak, pay attention to when and where the moisture appears. Condensation will usually form on the inside pane of the double glazing unit and will be most noticeable during colder weather or when humidity levels inside the home are high. Leaks, on the other hand, may cause moisture to appear between the two panes of glass or along the window frame, and they can occur regardless of the temperature or humidity conditions.

Related: Main areas where you get condensation in double glazing?

Temporary Solutions for Clearing Condensation

If you’re dealing with condensation on your double glazing, there are several temporary measures you can take to clear the moisture and improve visibility through your windows.

Using a dehumidifier

A dehumidifier can help to reduce humidity levels in your home, which in turn can minimise the formation of condensation on your windows. Place the dehumidifier in the room where the affected windows are located and run it until the condensation clears.

Opening windows for ventilation

Improving ventilation can also help to reduce condensation. Try opening your windows for a short period each day to allow moist air to escape and fresh, drier air to enter. This is especially effective if you can create a cross breeze by opening windows on opposite sides of your home.

Using a fan to circulate air

If opening windows isn’t practical, you can use a fan to help circulate the air in the room. Direct the fan towards the affected window to help evaporate the condensation more quickly. Just be sure not to leave the fan running for extended periods, as this can actually contribute to higher humidity levels.

Long-term Solutions for Preventing Condensation

How to Clear Condensation from the Inside of Double Glazing

While temporary measures can provide relief from condensation, it’s important to address the underlying causes to prevent the issue from recurring. Here are some long-term solutions to consider:

Improving ventilation in the home

Installing exhaust fans

Exhaust fans in moisture-prone areas like bathrooms and kitchens can help to remove humid air before it has a chance to spread throughout your home. Make sure to run these fans during and after activities that generate moisture, such as showering or cooking.

Using trickle vents

Trickle vents are small openings installed in window frames that allow for a controlled amount of ventilation. These vents can help to maintain a consistent flow of fresh air into your home, reducing the risk of condensation forming on your windows.

Maintaining consistent temperature

Using thermostats

Installing programmable thermostats can help you maintain a consistent temperature throughout your home. This reduces the likelihood of cold spots developing on your window panes, which can attract condensation.

Avoiding drastic temperature changes

Try to avoid making sudden, drastic changes to the temperature inside your home. Rapid cooling or heating can cause the glass in your double glazing to cool or warm too quickly, leading to condensation.

Related: What Double Glazing Glass Can I Choose?

Reducing humidity levels

Fixing leaks and drips

Leaking pipes, taps, or other water sources can contribute to higher humidity levels in your home. Regularly inspect your plumbing and promptly repair any leaks or drips to help control moisture levels.

Using moisture absorbers

Moisture absorbers, such as silica gel or calcium chloride, can help to reduce humidity in specific areas of your home. Place these absorbers in rooms prone to condensation, like bedrooms or living areas, and replace them as needed.

When to Seek Professional Help

While many cases of condensation in double glazing can be addressed through DIY solutions, there are times when it’s best to seek professional assistance.

Persistent condensation issues

If you’ve tried implementing various solutions but still find that condensation persistently forms on your double glazing, it may be time to consult a professional. A window specialist can assess your situation and provide tailored advice to help resolve the issue.

Suspected damage to the double glazing unit

In some cases, condensation between the panes of glass can indicate that the seal of the double glazing unit has failed. If you notice moisture or fogging that you can’t clear from between the panes, it’s best to have a professional evaluate the window for potential damage and recommend repair or replacement options.

Related: 5 Signs You Require a Professional Condensation Specialist


Condensation on the inside of double glazing is a common issue that many homeowners face. By understanding the causes of condensation and implementing appropriate solutions, you can effectively clear the moisture and prevent it from recurring.

Recap of solutions for clearing and preventing condensation

To clear condensation, you can use temporary measures like running a dehumidifier, opening windows for ventilation, or using a fan to circulate air. For long-term prevention, focus on improving ventilation, maintaining consistent temperatures, and reducing humidity levels in your home.

Importance of addressing condensation in double glazing

Addressing condensation is crucial for maintaining the energy efficiency and appearance of your double glazing. By taking proactive steps to control moisture, you can ensure that your windows continue to provide optimal performance and comfort in your home.


Can I use a hair dryer to clear condensation from my windows?

While a hair dryer can temporarily clear condensation, it’s not a recommended solution. The hot air from the dryer can cause the glass to heat up too quickly, potentially leading to cracks or damage to the window seal.

Is condensation more likely to occur in certain rooms?

Yes, condensation is more common in rooms with higher humidity levels, such as bathrooms, kitchens, and bedrooms. These areas generally have less ventilation and more moisture-generating activities.

Can double glazing with condensation still provide insulation?

While condensation can be unsightly, it doesn’t necessarily impact the insulating properties of double glazing. However, if the condensation is caused by a faulty seal or damage to the window unit, the insulating performance may be compromised.

How often should I run a dehumidifier to prevent condensation?

The frequency of running a dehumidifier will depend on the humidity levels in your home. As a general rule, aim to keep indoor humidity between 30-50%. Running the dehumidifier is needed to maintain this range, and be sure to empty the water collection tank regularly.

Can condensation on double glazing lead to mould growth?

If left unchecked, persistent condensation can create damp conditions that are conducive to mould growth. To prevent this, it’s important to address the underlying causes of the condensation and regularly wipe away any moisture that accumulates on your windows.

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