Condensation Control

Condensation is the change of water from its gaseous form (water vapour) into liquid form.  Arguably it is the most common type of damp related occurrence we see in buildings, nearly all of us at some point in our life’s have awoken to find water droplets running down our windows. 

This liquid forming on your windows is called Condensation, the reason this happens is all down to the temperature inside and outside the property as well as the amount of moisture in the air on the inside of the property. This will differ between all properties and is dependent on the activities of each household, (e.g. cooking, breathing, hot showers, & drying clothes all increase the moisture contained within the air. 

When this water laden air encounters a surface that is colder than itself, the warm air is unable to retain the same amount of water, therefore releasing physical water onto the cold surface. The point at which water in the air changes from vapour to liquid is called Dew Point or Point of Saturation. 

Running water on windows or walls will perhaps be the first indication of a condensation problem within a household, if ignored this can lead to the deterioration of the décor features within, causing wallpaper to bubble and peel, curtains to stain, and a general musty smell of the property. Ultimately black spot mould will begin to grow in the poorest ventilated areas which can aggravate health problems such asthma and wider complaints. 

Condensation is caused when warm air full of moisture encounters a cold surface, most commonly this tends to be situated around the windows or external walls. Condensation is often associated with poor ventilation in the property and becomes more apparent in winter, this is because the external walls and windows are at the coldest over the four seasons. 

Warm air absorbs moisture through our daily standards of living, on average an individual’s daily routine of cooking, shower’s, drying clothes, and breathing will generate approximately 1 pint of water per day, 7 pints per week. 

Rising air currents carry this moisture laden air upwards until it meets a cold surface, before the days of double glazing, cavity wall insulation or pre-fab roofing designs, this humid, stale air would find an escape route through the loft, or warped timber window frames, and as a result would be replaced with cold fresh air. Today, however there is no natural escape route in modern homes for this stale, humid air which in turn causes condensation and poor indoor air quality. 

Understanding the physical properties of air gives us a better view on how condensation occurs, a given volume of air at 20°C (68°F) can hold twice the amount of water vapour than at 10°C (50°F). The saturation pressure of water vapour increases with temperature. The actual partial pressure of water vapor is proportional to the amount of moisture in the air, so when the temperature rises, you can put more moisture into the air until the vapor pressure hits the saturation pressure. At that point the relative humidity is 100%, If you then take this saturated humid air and cool it, the saturation pressure drops, and suddenly the air has more moisture in it than it can retain in vapor form, so it condenses against a cold surface,, this is why a can of coke sweats, it cools the air next to it and moisture from the air condenses on the outside of the can.

Treating Condensation begins with establishing the main cause, weather this is poor living conditions, unsuitable extractor fans or general poor ventilation.

 Old extractor fans were commonly wired up to activate with the light switch, this works well if the lights are left on after a shower or bath, although most people tend to turn the lights off after exiting the bathroom therefore leaving any humid air free to travel around the property.

 One way we combat this at Leodis Damp Control is by fitting the latest ELEGANCE EL1003 this SAP Q Eligible fan combines the latest technology with energy saving efficiency.  It is a silent running, three speed fan designed to run continuously at pre-selectable choice of 2 lower speeds.

We also fit the latest Positive Input Ventilation Systems which are commonly situated in the loft to gain maximum operational potential. 

The PIV Loft is a loft mounted ultra-quiet, low energy home ventilation system. They work by pulling the cold, fresh air from the loft space into the units filters where the air temperature increases before passing down via ducting and air vents into the main household, constantly circulating fresh air stopping any build up of condensation.