The best smart humidifiers of 2026 for dry winter air

Measure first with a hygrometer: below 40% a humidifier can help, above 60% you need a dehumidifier. In a cold winter, heating dries out indoor air, and that is when a humidifier earns its place, especially in a bedroom. Dampness is more often a problem in a basement or during humid summer weather. Adding moisture to a home that already has condensation on the windows will only feed mould.

For most bedrooms an evaporative model is the safer choice, while an ultrasonic one is quieter and cheaper to buy. Ultrasonic units throw the minerals in tap water into the air as fine white dust, which shows up quickly if you have hard water. Evaporative humidifiers trap those minerals in the wick and naturally slow down as the room gets more humid. Either way, pick one with a built-in humidistat.

A few cents a day for an ultrasonic or evaporative model, but steam humidifiers cost far more. The math is watts × hours ÷ 1,000 = kWh: 30 W for 10 hours is 0.3 kWh, about 3¢ at an example rate of 10¢ per kWh. A 400 W steam model over the same 10 hours uses 4 kWh, about 40¢ a night. Check the wattage on the spec sheet and the rate on your bill, which depends on your province and utility.

Yes, it can: water left standing in the tank grows bacteria and mould, and an ultrasonic humidifier sprays them straight into the air you breathe. Empty and refill the tank every day rather than topping it up. Clean and descale it weekly with diluted white vinegar or citric acid, then rinse well. If you notice a musty smell or start coughing when it runs, switch it off and clean it thoroughly.

The usual culprits are mineral scale on the ultrasonic disc, a float stuck in the water tray or a wick clogged with minerals. Clean the disc gently with a cotton swab dipped in vinegar, without scratching it. Check that the tank sits properly and the float moves freely, and replace a hardened wick. If the fan runs but nothing comes out after cleaning, the transducer may have worn out; some brands sell it as a spare part.