The condensation in my home was so severe that on winter mornings I’d wake to misty windows with pools of water on the frames and sills. Mopping up the puddles with a sponge became my daily a.m. chore!
The timber framed leaded glass windows are an original feature of the house, which was built in 1926. Regular maintenance of the exterior was to be expected, however the condensation caused the inside of my windows to look weathered! The excess moisture streaming off the glass made the paintwork blister and flake. Having to decorate the inside of my windows almost as often as the outside was crazy!
I needed to find out what was causing so much condensation, and how I could prevent it. Would a few simple, inexpensive changes make a difference or did my home have structural defects in need of attention? Was the mould, which was starting to form, hazardous to health?
Condensation results from warm, moist air coming into contact with a colder surface or air which is at a lower temperature. Water vapour held in the warm air releases to form condensation on the cooler surface. Much like the steam from a bath, shower or kettle ending up on a cold window or tiled wall.
The daily activities of a family of four living in an average three bedroom home could quite easily release 10kg of water into the air. Having a bath or shower, cooking, putting on the kettle, drying laundry on a radiator and even breathing, all contribute to causing condensation.
More serious causes lie in defects such as rising damp, a failed damp proof course, faulty guttering and rainwater pipes, a damaged roof and internal plumbing leaks. If you suspect any of these to be the issue, it would be wise to call in a professional.
Black mould which grows when there is severe condensation can cause ill health in some people. The mould produces tiny spores or seeds which when inhaled can irritate the lungs and throat. Also, dust mites, which are a common cause of asthma and other allergic symptoms, thrive in a home with higher levels of humidity.
Thankfully, there were no structural faults with my home, however a problem did exist and it had to be dealt with – after all, I was fed up wiping the wet windows sills and cleaning the mould that was starting to form.
Here are some tips I discovered and used to reduce condensation in the home:
Dehumidifiers
Dehumidifiers remove the excess moisture in the home and help maintain a more constant level of humidity. A key feature to look out for is the extraction rate of a dehumidifier. This is an important factor in determining how effective the machine will be. The figure is quoted as the amount of water, in litres, which can be extracted in a 24 hour period. In the UK, a typical 3 bedroom home requires a dehumidifier with an extraction rate of 18litres/24 hours or above.
Some models have an auto-stop feature – allowing the unit to stop when the water tank is full. Others will require plumbing kits to provide a permanent drainage facility. Advanced features include variable speed settings and humidity sensors which adjust the extraction speed of the device based on the moisture level in the home. As a these machines need to operate for prolonged periods of time and possibly overnight, check models for energy efficiency and noise level.
A good domestic dehumidifier will cost around £130-£180. Judging by the low stock levels of high street and online retailers last year, the dehumidifier seems to be a very popular choice for dealing with what appears to be a common problem in condensation.
Moisture Collecting Crystals
A friend recommended this item, which is an economical solution although not as effective as a dehumidifier. The crystals go into a plastic container and can be placed wherever excess moisture is causing problems – like wet window sills caused by water streaming down the windows.
The collected water can be poured away from the container and when the crystals dissolve, refills can be bought to top up with (every six to eight weeks). This item can be purchased for £4 - £10.
Extractor Fans
Extractor fans are a definite must-have in all homes as they help remove the moisture from the two main rooms that cause it – bathrooms and kitchens. They can be wall, window or ceiling mounted and there are many different models to choose from and with varying features.
The effectiveness of an extractor fan is measured by its rate of air flow, which is the number of complete changes of air within the room per hour. Typically a kitchen requires 10-15 and a bathroom 6-8 changes per hour.
The capacity of a fan is defined as volume in cubic metres (m³), or cubic feet (ft³), per hour. To determine the minimum capacity of the extractor fan required, you will need to calculate the volume of the room (length x width x height) then multiply that by the recommended number of air changes required. So a kitchen measuring 15m³ (3m long x 2m wide x 2.5m high) and requiring 10 air changes will need a fan capable of extracting 150m³ per hour.
Many extractor fans have timers which allow the product to continue working even after you have switched it off. The idea behind this is that when you leave the bathroom, the fan continues to extract the steam and turn itself off after 10 minutes, which frees you from having to return to the bathroom to turn it off. Advanced features are sensors which turn the fan on when the humidity in a room reaches a pre-determined level. Some models will activate when the sensor detects movement in the room.
As with a dehumidifier, a key point to consider when buying an extractor fan is its noise level. This is listed as the sound pressure level in decibels at three metres. One of the quieter models on the market is listed as operating at 26.5 db(A)3m. Domestic extractor fans can vary in price from around £15 to over £100.
Other points to take note of in reducing condensation:
Air Bricks allow for air circulation below suspended timber floors – ensure they are not blocked – a damp specialist advised me to install an extra airbrick in my lounge.
Single glazed windows will always attract condensation as their temperature on the inside is almost the same as that on the outside. So, like me, you will always have wet window sills in the morning. Secondary or double glazing can help with this issue; of course, one resolution is much more expensive than the other.
Wherever possible try to dry laundry outside of the home – weather permitting. In our home we've no space for a tumble dryer, therefore in winter, clothes end up on the radiators. Our dehumidifier has a laundry drying setting, which is useful.
After a bath or shower, open a window in the bathroom and then close the door when leaving. This will ensure that excess moisture leaves the building instead of escaping into the house.
I implemented several of the above tips in my own home and have reduced the condensation to the point where I no longer have streaming windows and wet window sills. We all have to accept a bit of condensation, as long as it’s not causing a problem for us. However, the condensation I’d like to learn to live with is the one on a cold bottle of beer served in a bar on a Mediterranean beach!
Thanks
MikeM
To successfully eliminate mould from the house, you need to draw in fresh air from outside, filter it, and create a positive pressure (only slight!) within the house. This drives out the damp air, and the mould is killed. After about 2 weeks, it can be simply brushed away. Unlike de-humidifiers, the loft unit which does this job never needs emptying, is silent and runs all year at a cost of 1p per day!
ReplyDeleteYou're Crazy maan!!
DeleteI dont think you want to open window in this sub-zero temperature. If you do - whats the point of radiator being switched on and Double Glazing?
That will cost you more than 1p to warm the house. Crazy man!!