When in heating mode, people are confined indoors with unusually dry air for extended periods each year. Humidifiers help create the ideal humidity level and comfort, 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 lugging a humidifier from room to room, spilling water on the floor as you go.