Condensation
We are noticing the phenomenon of condensation more and more these days due to our changing lifestyle, with well insulated and draught proof houses, central heating, showers and our desire to keep heating bills to a minimum.
Years ago houses had airbricks in most rooms, large open fires with chimneys, windows that were not entirely draught free and no other form of heating appliances. The natural ventilation in these houses prevented condensation occurring due to air movement / air changes in the dwelling. Today we are building our houses in an altogether more energy efficient way, by installing thermal efficient uPVC draught proof windows and doors, central heating and fully insulated walls, floors and roofs. Hence any moisture produced now stays in the dwelling because there is no air movement / air changes.
In order to reduce condensation in our houses, we must first of all understand what condensation is and how best to deal with it. Condensation is caused by the production of moisture in the air and that air then comes into contact with a cold surface. The moisture then condenses into water vapour onto that cold surface, this moisture content is known as relative humidity (RH). An average family can produce about 18 pints of moisture a day, which disperses into the warm air in our houses. This moisture is created from such sources as:- drying clothes on radiators, tumble dryers (not vented), boiling a kettle, running a bath or shower, cooking, washing, calor gas heaters and breathing.
The higher the temperature in our houses the more moisture this warm air can hold, if this RH rises too high mildew will form in all areas of the home. The moisture in this warm air will condense when it comes into contact with a cool or cold surface, places such as:- metal windows and doors, the cooler edges of glass sealed units (particularly in bathrooms and kitchens), cold walls, floors and ceilings in less well insulated older properties or unheated rooms.
So how do we overcome this problem? We must first look at reducing the amount of moisture we are creating. Avoid drying clothes on radiators, but if you must, try to confine this to one room, close the door and open a window. If you have a tumble dryer that has a condenser this will be fine, if not ensure that it is fitted with an extraction venting kit to expel the steam outside. We all need to take baths and / or showers, so again try to ensure that the door is closed and the window opened (even if you open the window immediately after). Generally, try to confine any moisture producing activity to one room and ventilate to change the moisture-laden air with fresh air.
Next we must look at heating areas where condensation is forming, i.e. unheated rooms and conservatories, try whenever possible to provide some form of heating to these areas in cold weather or to keep doors to these areas closed to eliminate the possibility of moisture laden air entering. Some overnight heating in winter months can help by reducing the temperature difference between day and night.
Finally, we must ventilate to change the air, this can be achieved by simply opening a window (we all need fresh air in our houses from time to time), but as we are always trying to keep our houses warm and comfortable and we are aware of the cost of heating so we are reluctant to do this as this will result in us having to turn up the thermostat to increase the temperature again. Another option is to purchase a de-humidifier unit, which will extract the moisture from the air without making the room colder.
By installing uPVC framed windows which are a much better insulator than aluminium framed windows, having double glazed sealed units not single glazing in the frames, thereby increasing the thermal properties of the windows so reducing the onset of condensation in the first place.