35. Construction - Healthy House - The Atmosphere of Your Home
Condensation most commonly occurs when water vapour in the air (known as humidity) turns to liquid when meeting a colder surface. A visible example of this can sometimes be seen on the inside of windows or on morning dew. The temperature at which this happens is called the dew point. Condensation is the opposite of evaporation.
Regardless of temperature, humidity is often higher indoors than outdoors because activities like cooking and showering increase the moisture content of the air. Each person creates about 1L of water a day just by breathing alone.
In winter, because the interior is typically warmer than the exterior, air pressure is higher indoors than outdoors.