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Preventing condensation with Philip Whear

Some advice on preventing condensation from Philip Whear

It’s the time of year when trying to prevent condensation is at its most prevalent. Here in Cornwall, with our often fairly saturated maritime climate, many of you will be familiar with condensation on your windows, particularly in the winter months. Not only does condensation make your home damp and cold but it is often the cause of unsightly and potentially hazardous mould, read on for our advice on preventing condensation.

Condensation is created by excess moisture in the air and isn’t limited to just windows. It will occur on the coldest surface in the room. Microscopic droplets of water all around us become more concentrated when it the air is humid. Known as the dew point, when these molecules in high concentration come close enough to each other around a cold surface they coalesce into visible liquid i.e. condensation. Read on to find out how to reduce condensation in your home.

Understanding the cause is the key to preventing condensation. Anything that creates moisture will contribute to humidity, this can be anything from people breathing (0.2 litres/hr per person), drying laundry (5 litres per load) to a shower/bath (1.5 litre per shower or bath). Airflow is key to reducing moisture in the air (hence why bathrooms have extractor fans).

Warm, sealed up rooms with a moisture source will inevitably have condensation occurring.


A great way to prevent condensation at home is by maintaining a steady lower temperature for a longer period of time. If possible, keep a low heat on all day, coupled with background ventilation, rather than bursts of higher temperatures in sealed rooms with a moisture source. To help with this, insulate areas that are susceptible to condensation; colder surfaces like windows, window reveals and external doors.


Ventilating can help you prevent condensation in your home by removing the moisture that’s in the air. Make sure to increase ventilation in the kitchen and bathroom when they are in use so that the steam from various heat sources like showers, kettles, or hobs doesn’t form condensation.

Air rooms

If possible, open up vents in windows to let fresh air in and moist air out, especially first thing in the morning after a night of warm air being trapped in your home. If you have trickle vents fitted on windows, open them up to allow a steady stream of ventilation without compromising on the temperature of your home.

Allow air space around furniture

Locate wardrobes, cupboards and other furniture against internal walls rather than external walls. If your furniture is against external walls, make sure to leave a gap of ~50mm behind furniture to allow space for the air to circulate in and around your furniture. This way there is space for the moist air to travel rather than forming on walls and creating damp mould.

Remove sources of moisture

Reduce the amount of water entering your home. If water has already entered your home make sure to wipe it away as soon as possible. This will prevent the condensation from settling and forming mould which will be more challenging to remove than water.

Dry washing

Dry your clothes outside if you can, but if this isn’t an option, think about drying them in the bathroom or kitchen. To prevent condensation, keep the extractor on with windows open and doors closed so the drying is contained in one room.

Tumble drying

If you have a tumble dryer, vent it to the outside. Removing excess heat and moisture allows the damp air to escape so it completely avoids potentially cold surfaces in your home on which to form damp mould.

Put lids on pans

Just like you would close doors to rooms like your kitchen and bathroom which tend to generate more moisture, close off the source of the steam too where possible. This includes doing things like putting lids over pans and making sure shower curtains are pulled to keep moisture contained. By doing this, less moisture is produced and spread around a room, decreasing the chances of it landing on cold surfaces and forming condensation.

Clean away mould

If you already have condensation that has formed mould in your home, this shouldn’t be too challenging to remove if you act fast and clean it off as soon as you see it forming. Use a mould cleaning product to eliminate the smell and make sure walls and surfaces are clean and dry after use. Black mould has been proven to have negative effects on health, so stopping this at the source is the best means of prevention.

Double glazed doors and windows

Double glazing not only helps keep the heat in but it also helps in preventing condensation. The reason we see so much condensation on a single glazed pane is because it is more susceptible to the cold which stimulates the dew point from the water vapour in the air. The gap between the two panes of a double glazed unit acts and an insulator and helps to keep the internal pane of glass closer to room temperature and it is this temperature difference that stops the water vapour from reaching the dew point and forming condensation on the glass. While this is effective, double glazing can’t eliminate condensation entirely, so following a combined approach of windows, ventilation and reduced moisture is the only way to completely get rid of it.

Note – without following the tips above to improve ventilation and reduce moisture, the improved thermal performance of modern double glazing may simply relocate the condensation issue elsewhere.

Ventilation Systems

Old properties were often draughty and poorly insulated. Over time, our homes have become more energy efficient, warmer and less draughty, but the trade off has been trapping warm humid air that leads to condensation and mould. Along with double glazing to better insulate your home, many modern buildings are having Positive Input Ventilation systems installed to extract humid air from indoors and draw in drier air from outdoors. A very cost effective equivalent of this is opening your windows to let fresh air in!

How can we help?

Get in touch with us today to find out more about double glazing options for both windows and doors and how this can help you start preventing condensation in your home, keeping it warm and dry for the remainder of the colder months.