When in heating mode, people are confined indoors with unusually dry air during a long period 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 your more typical room humidifiers. They add moisture into the air, making harsh, dry air much easier to breathe. And whole-house humidifiers help make the whole house comfortable, no more carrying a humidifier from room to room, spilling water on the floor as you go.