Achieving the right balance of in-home humidity
We all need a certain amount of humidity inside our homes for comfort and health reasons. Too little humidity can lead to occupant complaints while too much humidity can result in problems ranging from condensation on windows to mold growing on surfaces. Mold can cause varying effects, from minor irritation to allergic reactions and illness.
The most reliable way to measure the humidity in your home is with a hygrometer – a small, inexpensive and easy-to-use tool available at most hardware, department, building supply and electronics stores. In general, your indoor RH (or Relative Humidity) should drop to about 30 per cent in very cold weather.
If your house is too dry during the winter, itʼs probably leaking too much air. To seal your home, contact your local Natural Resources Canada (NRCan) office to arrange to have a qualified EnerGuide for Houses inspector test your house, and then follow his or her advice to make your home more comfortable and efficient. To find an NRCan office near you, visit their website at www.oee.nrcan.gc.ca
If your house is too damp in the winter or there is excessive condensation on the windows, Canada Mortgage and Housing Corporation (CMHC) has a number of practical tips you can use to help solve humidity hassles, including:
• Identify excessive sources of moisture, such as a leaky or damp basement or a crawlspace with a dirt floor. If you do locate a source of excessive moisture, fix it as soon as possible before the coldest weather sets in.
• Run your bathroom fan during your shower and and for 15 minutes after, and use a vented range hood while cooking. Consider replacing noisy or inefficient bathroom fans with a small, quiet and energy-efficient model that can run almost unnoticed, while also saving you money.
• Adopt practices that help dry the house, such as hanging clothes to dry outside rather than inside, using a vented clothes dryer, storing firewood outside and using a dehumidifier in the basement during the summer months to fall.
• You may need to raise the temperature you keep your house. Cold surfaces in unheated or poorly heated spaces are prone to condensation.
• If your house is still damp, it means a major source of moisture has not been corrected. Try increasing the ventilation by leaving a bathroom fan running, and then check your hygrometer in a couple of days to see if the relative humidity has gone down.
•Finally, for some homes, installing a heat recovery ventilator (HRV) can also be a good solution for winter dampness. While the installation costs for an HRV will be higher, they can also result in significant savings over the long run.