How does condensation occur:
Condensation is the conversion of vapour to liquid. Condensation occurs when warm, moist air comes in contact with a cold surface. The moisture that collects on windows is a visible example of condensation.
Why does condensation occur:
Condensation occurs because of a temperature difference that exists between the warm interior of your home and the colder outdoors.
Contributing factors to condensation:
The air around us contains humidity, and we add more water vapour to it by normal breathing, perspiration, cooking, cleaning, and showering.
The following matrix can help you determine when to expect condensation:
Example: if it is – 28 oC outside and your home reads more than 15% humidity, you will likely see condensation on your windows.
Outside Air Temperature in Degrees Celsius oC
-28 oC or colder - keep humidity below 15%
-23 to -27 oC - keep humidity below 20%
-17 to -23 oC - keep humidity below 25%
-12 to -16 oC - keep humidity below 30%
-6 to -11 oC - keep humidity below 35%
+4 to -5 oC - keep humidity below 40%
Help control condensation:
Make sure the weep holes of the condensation gasket at the bottom of the skylight are free from debris. This will enable the weeping system to shed water.
Reduce the humidity in any room, especially the bathroom, with an exhaust or ceiling fan.
Install a fan in the tunnel of the skylight.
During the winter months, install a plastic barrier at the skylight level that will prevent the humid air inside from touching the cold glass pane.
Run a dehumidifier during the winter months.
Did you know:
The humidity at waist level could be up to 100% greater at the skylight level.
All moist stale air should be replaced with fresh air every 3 to 4 hours.
Moisture is continually being released inside your home, 10 to 50 litres every
Resources: www.cmhc.ca