Condensation often occurs in cold weather when moist air inside a house comes into contact with cooler surfaces. The moisture in the air can condense to form water droplets or frost. The lower the temperature or the higher the indoor humidity, the greater the risk of condensation.
The easiest way to eliminate this vapor from windows is by letting fresh air into the room, but the outside temperature must allow it.
Condensation can form on windows, doors, and skylights:
- on the glass
- on the frames and sashes
- near the weatherstripping
- on the walls around a skylight
- between the panes of glass if the seal is no longer airtight
Healt Canada recommendations
Based on the chart below, Health Canada (2007) recommends that the RH in your home is kept below 50% in the summer and between 30-35% in the winter (Figure 1).
Here are some tips for reducing humidity levels to keep your home comfortable:
- Remove and store window screens for the winter.
- Leave curtains open to air out the surface of the glass.
- Seal cracks or leaks in the foundation, roof, walls, and window frames.
- Make sure rainwater, irrigation runoff, and meltwater drain away from the house by correcting the slope of the ground so that water flows away from the building.
- Clear gutters and downspouts of debris and make sure water is directed away from the house toward the street.
- Cover the dirt floor of the crawl space or basement with thick polyethylene (waterproof and weighted).
Here are some good habits to help control indoor humidity.
- To remove cooking vapors, run the stove fan.
- Run the bathroom fan or open a window while keeping the door closed when showering or bathing.
- Make sure the clothes dryer vents outside the house.
- Avoid hanging wet laundry inside the house.
- Turn off any humidifiers until you achieve the recommended humidity level.
- If you do not have an air exchanger, open windows on the ground floor or upper floors to allow air to circulate.
Source: https://publications.gc.ca/collections/collection_2018/sc-hc/H144-33-2016-eng.pdf
A proven solution
Buy high performance ENERGY STAR® certified windows, doors and skylights. They are more energy efficient and have less condensation compared to ordinary models.
Features that contribute to better energy efficiency are:
- Triple glazing;
- Low-emissivity (low-e) coatings on the glass;
- Inert gas between the glass panes;
- Thermally improved spacer bars;
- Insulated frames, sashes and doors;
- Increased air tightness.
SOURCE: Natural Resources Canada