What humidity level should my house be in winter?

Indoor humidity during Ottawa winters should be maintained between 30-40% to balance comfort, health, and protection of your home. This range prevents the air from becoming too dry while avoiding condensation problems that can lead to mold and structural damage.

Why winter humidity matters so much in our climate is that cold outdoor air holds very little moisture. When that frigid air enters your home and gets heated, it becomes extremely dry - often dropping below 20% relative humidity. This dry air causes static electricity, dry skin and throat irritation, and can even crack wooden furniture and flooring. Your furnace's operation compounds this by constantly circulating and heating already dry air.

The challenge with Ottawa's cold winters is that if you add too much humidity, it will condense on cold windows and walls, potentially causing mold growth and damage. This is especially problematic in older homes with less efficient windows. Many Ottawa homeowners find they need to adjust their target humidity based on outdoor temperature - aiming for 35-40% when it's mild, but dropping to 30-35% during those brutal -20°C stretches we get in January and February.

Monitor your humidity levels with a simple hygrometer (available at any hardware store for under $20) and watch for signs you need adjustment. If you see condensation forming on windows, you have too much humidity. If you're experiencing frequent static shocks or your hardwood floors are showing gaps, the air is too dry. Most modern thermostats also display humidity levels.

For adding humidity safely, a whole-home humidifier integrated with your furnace system is the most effective solution. These systems automatically maintain your desired humidity level and are much more reliable than portable units. If you're experiencing humidity issues or considering a whole-home humidifier installation, a professional assessment can help you choose the right solution for your Ottawa home's specific needs.