Humidity levels can lead to mold and mildew
The relative humidity or moisture level in your home is important to keep in check or you may find mold and mildew problems and health hazards arising from black mold or other toxic molds.
Condensation on windows is the most noticeable sign that you have excessive humidity levels in your home. A little condensation is to be expected, but high humidity often causes consistently foggy windows and should be addressed. Household condensation can happen on all surfaces in the home when moisture levels are too high. Inefficient windows (i.e. single pane with aluminum frames) or inadequate ventilation can result in condensation, frost or pools of water on windows and sills. When water vapor comes in contact with a surface that has a cooler temperature, such as windows, the vapour turns into droplets of moisture on the glass. This vapor also adheres to walls, which can be a more serious problem because it can penetrate walls and constant excess moisture can lead to mould, mildew, and deterioration of your drywall.
Tips to control humidity levels in your home
Humidity comes from everyday living: steamy showers, boiling water, washing machines, dryers, wet and snowy boots, and many other sources. Poorly insulated crawl spaces can increase humidity, often resulting in a musty odor. There is no such thing as a condensation-free window and windows do not cause condensation; they simply prevent moisture from escaping to the outside. Seeing condensation on windows signals that steps need to be taken to reduce the moisture in the air inside your home:
- Regularly use ventilation fans in kitchens, bathrooms and laundry rooms to circulate air.
- Squeegee your tub surround and shower enclosure; use your towel to dry off the excess moisture and leave your bathroom ventilation fan on for at least one hour after every shower.
- Open interior doors and windows to circulate air flow.
- If you have a humidifier or dehumidistat, set to the correct outside temperature settings.
- Make sure you have adequate ventilation through soffits, roof ridge, basement and crawl space.
- Install energy-efficient windows.
Think of your house as a system, keeping in mind that one reason you’re seeing these changes in your home after your upgrades is your new high-efficient heating system operates differently than your old furnace.
Exhaust ventilation has to be provided to accommodate increased relative humidity in the home, otherwise high humidity may be the outcome.
Heat Recovery Ventilators (HRV) and exhaust ventilation extract moist, stale air from the home, allowing fresh air to come into the home through makeup air vents. An additional benefit of an HRV is that it will bring fresh air from outside into the home, and while that process is occurring, the fresh air is being warmed or cooled depending on the time of year within the HRV.
Ideal Relative Humidity Settings
Relative Humidity Settings Moisture levels must be controlled within the home. The following settings are recommended: Relative humidity should be as follows; Summertime is 50 per cent to 60 per cent
Outside Temperature…Living Temperature…Inside Relative Humidity (inside home)
Above 0°C…21°C…40 per cent
-5°C …21°C…35 per cent
-10°C…21°C…30 per cent
-20°C …21°C…25 per cent
-30°C …21°C…20 per cent
You may also want to read Understanding Home Moisture and What is Moisture?