Healthier home: ventilate to avoid condensation

Poor indoor air quality is in no small part down to humidity which leads to condensation, damp and mould. But you can do something about it without spending a fortune...

By Noah Dugall
ventilate for indoor health

If your windows are covered with condensation, then you need to open them. Obvious, yes, but it's astonishing how reluctant many of us are to open windows except in high summer

According to research by Ecoair, a company that manufactures dehumidifying products, nearly 80 per cent of Britons have lived in a property affected by condensation, damp or mould. Yet despite this, over one in five of us are unaware of the problems caused to a building caused by moisture in the air.

And most of us never check humidity levels in the home and wouldn't have a clue how to go about it. But we do believe - wrongly - that in winter we should keep windows closed, doors sealed and turn the heating up high.

But this results in increased humidity which causes health problems as well as visible problems such as damp and mildew. That's because moisture in the air creates an ideal breeding ground for microorganisms including bacteria, viruses and allergy triggering dust mites. And homes exposed long-term to excess moisture have a much higher chance of harbouring lung-damaging and sometimes highly toxic mould.

Ecoair's research highlights factors mistakes we make when temperatures drop.

Don't be frenzied about blocking gaps, vents or using draught excluders under every door.

Even though it may be chilly, do open the windows for short periods and don't have central heating on all the time.

Kitchens especially need regular ventilation because moisture builds up here as we cook and boil kettles.

Bathrooms too are significantly affected by humidity and huge numbers of us never open our bedroom windows during the winter months, causing poor air quality.

Ecoair MD Sally Fok answers some key questions:

Why are our homes more humid in the winter?

'By turning on the heating and closing doors and windows during winter, we significantly reduce air circulation, causing moisture generated inside to become trapped indoors.

'Moisture from rain and melting snow can also enter our home through windows, floors or walls - particularly in older buildings.

'In the meantime, condensation of moisture on cold surfaces such as windows, ceilings, floorboards and walls, due to the difference between indoor and outdoor temperatures, is a major cause of trapped excess moisture in all homes throughout the winter.'

How are we exacerbating the problem?

'A huge majority of us are inadvertently making the problem worse and therefore putting our health at risk. It's a common misconception that turning the heating up will reduce humidity, however, warm air carries more moisture!

'Humid air in a warm interior will find any colder surface, such as windows or walls, to condense, generating more condensation. Closing windows and curtains, air drying or hanging laundry on the radiator, taking long baths or showers, blocking vents, draughts or gaps, boiling the kettle, cooking, even breathing… can all contribute to the build-up of excess moisture in our homes.'

Why is humidity dangerous and what are the signs?

'Airborne microorganisms thrive in humid conditions. The survival and breed rate of bacteria, viruses or dust mites for example, will escalate as soon as humidity levels rise above 60 per cen

'This level of humidity is not at all uncommon in UK homes during the colder wetter winter months and the visible signs do not necessarily present themselves immediately.

'Visible signs of humidity include damp, mould, mildew, condensation, rotting or warped wood, peeling paint… If these are present, humidity in your home is way above optimum levels, so it's vital to act quickly. As well as risking your health, you'll likely also end up with costly damage repair bills.'

Why is humidity particularly dangerous for children?

'Children have weaker immune systems so there is an increased chance of them catching infections.

'Bacteria and viruses thrive and spread rapidly in a humid environment, so once an infection is brought home by any member of the family, excess moisture present in the air will increase the risk of everyone else in the house becoming infected.

'A humid environment will also aggravate existing conditions such as asthma or eczema and can trigger numerous allergies. So to keep children healthier and defend against winter bugs during the colder months, it is strongly advisable to check humidity levels and ensure they remain below 60 per cent.'

How can we monitor the levels of humidity in our homes?

'Moisture levels can be measured by using a hygrometer. These are widely available online, inexpensive and will provide peace of mind.

'Any reading above 60 per cent and it'd be strongly advisable to take steps to address the problem.

'It's important to test all living spaces; it may be that the excess moisture only occurs in specific rooms.'

How can we protect ourselves against excess moisture build up?

'Ventilate. It is SO important. Good air circulation – even in winter - will allow excess moisture to escape and is key to warding off illness.

'Open windows regularly and use vent fans every time you are cooking and after taking a shower or bath. Allowing the air to circulate is a quick way to release trapped humidity.

'For those looking for a more immediate and controlled solution or in the case where humidity is continually showing levels higher than 60 per cent, a dehumidifier can successfully restore and maintain the correct moisture levels in the home by extracting moisture from the air.

'Once humidity levels in the home are brought down to below 60 per cent, airborne bacteria and viruses will not only stop breeding, but will struggle to survive.

'To control heavier cases of condensation on windows, damp or mould, it is advisable to bring the humidity down to 40 per cent during the winter months.'