Condensation-produced humidity: frequent causes and possible solutions

Sicrometry and humidity

Water is present on the planet in three states: liquid, solid, and gaseous. Of these three states, the gaseous state clearly predominates. The air that constitutes the basis of ventilation and conditioning processes is defined as a mixture of "dry air" and water vapor, which is commonly recognized as humidity in the air. Based on this description, relative humidity can be defined as the ratio between the weight of the water vapor contained in a volume of air and the weight of the saturated vapor of the same volume.

Z (%) = (Weight of vapor / Saturated weight) x 100

The humidity contained in the air greatly modifies its physical properties and greatly influences human physical sensations. Therefore, sicrometry has developed as a branch of physics dedicated to studying the thermal properties of humid air, its regulation, measurement, and the effect that humidity produces on materials and the comfort of individuals.

Condensation-produced humidity: possible solutions

Humidity due to condensation originates when the water vapor contained in the indoor air of a building condenses. This type of humidity forms on a cold surface, or at least on a surface whose temperature is lower than the dew point of the surrounding air. This point varies depending on the ambient temperature, being more frequent in colder areas, primarily on facades and on materials with a polished surface, such as window glass or the tiles in a bathroom. Thus, what initially is limited to an aesthetic problem ends up becoming a health threat that can lead to the appearance of mold and dust mites.

Condensation humidity usually manifests at night when building materials cool down. Its appearance is more frequent in certain construction components: single-glazed windows are more prone than those with double glazing with an air chamber. When the facade closing is made of hollow brick with an air chamber, it is essential to ventilate it to avoid condensation since this is where the humid, warm air mixes with the cold air coming from outside.

The best solution to avoid condensation humidity is to ensure that we are providing adequate ventilation to our home. If the layout does not facilitate natural cross-ventilation, it becomes necessary to install a mechanical ventilation system that keeps the living space with quality air. Other measures that can be taken are:

• Keep the kitchen and bathrooms closed to prevent steam from spreading
• Ventilate bathrooms and kitchens frequently if they have windows
• Do not block air outlets by placing furniture or appliances
• Keep the heating at a low level for a relatively long period