What’s my home’s humidity level – and why does it matter?

Just like temperature, having the right humidity level at home matters. Here’s how to know yours, and spot possible signs that it may need a fix.

When it comes to feeling more comfortable and saving energy, most of us turn to our thermostats. But there's another essential factor to consider: humidity.

Just like being too warm or too cold, having a humidity level in your home that’s too high or too low can have an impact on how you feel.
 
"Humidity alone isn't the only factor that can affect your home's air quality and comfort level, but when it combines with a temperature that’s also really high or low, it can be more troublesome," says Stephen Dixon, a consultant who helps businesses and homeowners use energy more wisely.
 
Take dry winter air as an example. It can cause chapped lips, staticky hair and clothes, and even occasional nosebleeds.
 
Humid summer weather, on the other hand, can also create annoyances. Mould and dust mites thrive in more humid environments - and both create problems for allergy and asthma sufferers. Plus, we all know how uncomfortable heat and humidity are when they’re combined (an effect that Canadian weather reports call the humidex). 
 
In the summer, an air conditioning unit typically helps prevent humidity as it cools your space down. However, a unit that is too large for the space and cools the air faster than humidity (water vapour) can be removed from the air can leave you feeling cold and clammy. If that’s the case, you may need a dehumidifier or to talk to a qualified HVAC contractor about other options.

Ideal humidity – and signs of trouble

Every home is different, but a level between 30 and 40 per cent humidity is typically ideal for keeping your home warm and comfortable in the winter, without leaving condensation on the windows. In the summer, that level can be higher, between 50 and 60 per cent.
 
So, how do you know your levels? That’s where a device that can measure humidity comes in. 
 
You may have a humidistat, which lets you monitor and control your home’s humidity level. Most humidistats are wired to a humidifier mounted right to your furnace, or they’re located on a wall elsewhere in your home.
 
They look and function a lot like your thermostat, but instead of measuring temperature and making adjustments, humidistats measure relative humidity in the air and turn your humidifier on or off in response. Most residential furnaces don’t have a dehumidifier function and only add humidity as needed. If your home is too humid, you still may need a portable dehumidifier to address it.
 
Dixon cautions that older wall humidistats are often inaccurate with their readings. On the plus side, most smart thermostats display the humidity level in your home (although they cannot control it). You could also pick up a hygrometer, an inexpensive device that helps measure moisture levels in your air at home, so you have the right information to make possible adjustments.
 
Understanding humidity in your home can give you a picture of where you may have opportunities to make your place more energy efficient, Dixon points out. Once you’re armed with the right information, you can take steps to improve your whole home.