How can condensation damage windows?

While uPVC windows are designed to resist water, overly wet seals and intense sunlight can cause them to dry and crack from repeated swelling and shrinking. 

Wooden frames are especially susceptible to damage: 

• Paint and varnish can peel 
• Wood trim will dry and crack 

The main concern from standing water and moisture is mold. If left untreated, mold will damage and discolor uPVC and wood. 

More importantly, mold is exceptionally bad for our health. 

Condensation and black mold 

The real issue with condensation is that it can lead to black mold. 

Patches of black mold around windows, doors, and walls don’t just look unsightly; they could make you seriously ill. 

The main symptoms of mold are: 

• Stuffy nose 
• Wheezing 
• Red or itchy eyes
• Skin rashes and itching 

WHO also reports that mold can contribute to the following: 

• Asthma 
• Allergic rhinitis 
• Hypersensitivity pneumonitis 
• Allergic alveolitis 
• Chronic rhinosinusitis 
• Allergic fungal sinusitis. 

There is more (non-proven) evidence that acute idiopathic pulmonary hemorrhage causes memory loss and lethargy in infants. 

Undoubtedly, mold is bad news and needs to be dealt with. 

Any mold that appears should be carefully cleaned and removed, and preventative measures should be implemented to eliminate condensation. 

How to stop condensation on windows 

The leading cause of condensation is a lack of ventilation. The remedy is to improve ventilation to help equalize humidity inside and outside a property. 

Once, houses had poorly fitted windows, doors, chimneys, and air vents that allowed air to circulate. However, houses have become much more energy-efficient over the last thirty years. As a result, many homes have become sealed, trapping moisture inside. While we have improved at keeping heat indoors, we have lost natural ventilation in our homes. 

To eliminate window condensation for good, you’ll need to: 

• Improving ventilation 
• Reducing moisture 
• Installing double or triple-glazed windows
• How to improve ventilation to reduce condensation 

There are several ways to enhance ventilation in your home: 

Airflow system 

Many new apartments have internal airflow systems to solve this problem. These systems use a network of ducts in the ceiling to pull air from outside and exchange it with the air inside. 

This maintains air circulation and a humidity balance within a well-sealed property. 

Retrofitting a ventilation system in a house is invasive and expensive and only sometimes possible in older homes. 

PIV Unit 

Positive Input Ventilation (PIV) units can be fitted in areas that produce excessive moisture for an easier-to-install solution, such as kitchens and damp basements. 

The system removes the damp air inside the home and brings in dry air from outside. This air exchange helps to maintain the right level of humidity. 

Extractor fan 

Sufficient bathroom extraction is essential to reduce the excessive humidity produced by showers. Some fans have a feature that automatically turns on the fan when the humidity exceeds a certain level. 

Kitchens also need sound extraction systems for cooking to remove smoke, smells, and moisture. 

Air vents/bricks 

Air bricks can get blocked to stop draughts, but they still work to keep an area ventilated. A simple vent can help manage humidity, which may reduce energy efficiency. As a result, air bricks are less popular than they were. 

Open windows let air in and prevent water from collecting on the glass. Most windows can have vents installed for this purpose. 

Opening windows 

Your grandmother may have opened the doors and windows every morning to let fresh air into her home. Nothing is better than allowing fresh air to circulate through space to keep it ventilated, remove stale air and smells, and reduce moisture in the house. 

Traditional windows provided adequate ventilation, essential when fossil fuels heated most homes. 

Sash windows were designed to open the bottom and top to draw air in and out, providing adequate ventilation. 

Bay windows have two casement windows on either side for better airflow and ventilation.  

Transom windows above a door help improve airflow inside a property, reducing heat and aiding ventilation.  

Modern windows come with multi-point lock settings, allowing them to be securely left open for ventilation. This is an easy and effective way to ventilate your home and prevent condensation. 

Reducing moisture to reduce condensation 

To prevent condensation, it’s important to reduce moisture and use ventilation. The average household produces a lot of water vapor daily from everyday living activities. 

Cooking Up to 3 litres per day 

Clothes washing 0.5 litres per wash 

Showers and baths 1.5 liters per person 

Washing dishes Up to 1 liter per day 

Un-vented clothes drying 5.0 liters per load 

Breathing, active adult 0.2 liters an hour per person 

Breathing, adult asleep 0.02 liters an hour per person 

Houseplants and pets add to the moisture in the air and can cause condensation. 

The most significant causes of excess moisture that causes condensation 

All of these areas should be addressed to try and minimize the impact they have on contributing to humidity in the house: 

• Cooking, boiling pans and kettles 
• Showers and hot taps 
• Washing machines and tumble dryers 
• Drying clothing on radiators or indoor airers 
• Large houseplants 
• Wet logs stored for wood burners 
• Unfound water leaks in cavities or under floors 
• Rising damp in basements and ground-level buildings 

Is it time to consider new double-glazing windows? 

Everest windows are designed to last, with long-lasting guarantees. 

Install double glazing to reduce condensation. 

Condensation forms on single-glazed glass because the glass is icy, causing the dew point from the water vapor in the air to increase. 

Double glazing reduces condensation because the glass is not as cold as single-glazed glass. The air gap inside the double-glazing helps keep the glass’s internal pane closer to room temperature. This temperature difference prevents the water vapor from reaching the dew point and forming condensation on the glass. 

Double glazing cannot eliminate condensation, so the best way to eliminate condensation is to use a combination of windows, ventilation, and reduced moisture. 

Do dehumidifiers stop condensation on windows? 

A dehumidifier is an option for internal spaces where you can’t open the window or for excessive dampness and moisture. 

Dehumidifiers extract excess moisture from the air and collect it in a tank that you would empty. The amount of water they can extract is always surprisingly high. However, always keep the windows closed as they try to draw in moisture from the outside. 

Dehumidifiers are a good idea for: 

• Drying clothes 
• Removing moisture from an attic or basement with a damp issue 
• Drying out after a leak or flood 

It is important to note that dehumidifiers only treat the symptom, and it is far better to treat the cause for a long-term solution. 

Condensation on the inside of windows 

If you have double or triple-glazed windows, condensation between the panes of glass inside the glazed unit means that the seals have failed on the glazing unit. 

Double-glazed units hold a low level of internal moisture. To stop the moisture from forming on the glass inside, the unit also has crystalline desiccant (like what you find in a new bag or shoes) contained in the spacer bar. The desiccant removes moisture from the air gap and maintains a dry internal space between the panes. 

Internal condensation occurs when the seals of the sealed unit start to deteriorate, allowing more moisture to enter the unit. The desiccant becomes saturated and cannot absorb moisture anymore, leading to condensation inside the unit. 

Condensation on new windows 

It would help if you never experienced condensation between the panes of new windows. 

If you experience internal condensation, there is a problem with the seals, which should be covered under a manufacturer’s warranty. 

Condensation forms on windows during the morning. 

In the early morning of summer, condensation appears outside the window. This means the air temperature outside is humid and warming quickly, but the glass is still cold. This is normal and will clear soon as the sun warms the glass. 

Condensation on bedroom windows 

Two adults sleeping can expire up to half a liter of water overnight. That’s an excellent explanation! I’ll make sure to remember it. The best way to control this is to open the window on a vent or the bedroom door with another window open for ventilation.