02 - Humidity in buildings

We are going to deal with residential buildings only, dwellings that serve as living spaces for human beings.

We know very well that the sun heats up the walls and roofs of buildings and that this heat is transmitted to the interior of the dwelling often making them unbearably hot.

But when the sun sets the walls, the roofs and the interior of the dwelling begin to cool off until the sun raises again the following day.

 

This cycle repeats itself every day of the year.

 

In addition to the heat it is very important to know that the air humidity level also builds up. There are various sources of humidity inside a building:

• in the kitchen where the water boils and the stew cooks, water vapor drifts off from pots and pans and joins the natural humidity in the surrounding air, increasing the level of air humidity in the building, 
• all human bodies generate water vapor, during the day or night, even though we often do not even notice that there is humidity coming out of our bodies, even when we are not perspiring,
• in the bathroom or toilet hot water evaporates, fogs our mirrors and the glass in the windows, and this water vapor drifts into the building turning the air even more humid inside the dwelling.

This humidity keeps building up in the air, in our clothes, in the walls and makes the air inside the building more and more humid. Humid air is less comfortable, be it during hot or cold weather. The higher the humidity in the air the less bearable will be the cold or the hot weather.

Humidity contributes to the discomfort in a dwelling but the humidity will also give rise to the development of mold, fungus, other microscopic organisms and even insects that are not good for our health. 
And so, to improve the level of comfort in our dwellings we have to ventilate the air inside the buildings to expel this excess humidity. The more the air circulates inside a building, the more natural ventilation, the more comfortable our building will be.