When in heating mode, people are confined indoors with unusually dry air during a long period each year. Humidifiers help the right comfort level of humidity, and properly maintained levels of humidity are beneficial for your respiratory system. Whole-house humidifiers work like old-fashioned room humidifiers. They distribute moisture into the air, making harsh, dry air much easier to breathe. And whole-house humidifiers add humidity throughout the house, no more moving a humidifier from room to room, spilling water on the floor as you go.