Relative humidity is a measure of the water vapour content of the air at a given temperature. It is expressed as a percentage of the maximum amount of water vapour that the air could contain at the same temperature. Relative humidity is dependent not only on the amount of moisture in the air, but also on the air temperature. The warmer the air, the more moisture it can hold. The opposite is equally true, in that, the cooler the air, the less moisture it can hold.
When the relative humidity of the air at a given temperature passes beyond itΓÇÖs saturation point it can no longer exist as water vapour. At that point it reaches the dew point and condenses into liquid water.
WhatΓÇÖs The Connection to Condensation?
In Canada, the temperature fluctuates with the seasons. In winter, obviously, the outside temperature is cold. Equally obvious is the fact that we keep the interior of our homes and buildings warm and comfortable, creating a significant difference between the colder outside air and the warmer inside air.
Inside our homes, we generate a significant amount of humidity. Everything from cooking to bathing to watering the plants releases water vapour into the air and, because the air inside our homes is much warmer, the relative humidity is higher than the air outside, just on the other side of the window.
