Today’s homes are insulated and sealed at a very high level to make them “air tight” and energy efficient. Older homes have many ways for the for the moisture to escape and therefore fewer problems with moisture in the house. Today’s homes are often smaller than previously, yet activities like showers, dishwashers, washing machines, gas furnaces and humidifiers all pour more water vapor into homes than in past years. All of this moisture must eventually escape from your home.
A family of four can release more than 18 gallons of water per week into the air of your home.
Condensation occurs on inside window surface whenever surface temperature falls below the dew-point temperature of the room. In a thermal sense the window represents the threshold for humidity to form because it is the coldest surface in the room. As a rule, the colder it is outside, the greater the likelihood of water vapor forming on inside surfaces, even at reduced humidity level in the home. For example: at -40°C condensation will form at only 25% humidity in the room. At -1°C the inside humidity level must rise to 63% before condensation will form
Actions to reduce condensation
- Ensure the humidifier is properly functioning and adjusted to suit the outside air temperature.
- Open windows and doors whenever practical or possible to allow interior moisture to escape.
- Open blinds or curtains to facilitate air movement.
- Use the ventilators when showering.
- Use ceiling fans to circulate air.
- Turn furnace fan on a continuous operation
Outdoor Temperature Relative Indoor Humidity
- 7°C 35%
- 12°C 30%
- 18°C 25%
- 23°C 20%
- 29°C 15%