Oooo…ultrasonic humidifiers… Unless you’re using distilled water in them, they pump out mineral dust which coats everything, included the insides of your lungs…
If you are using distilled water, that might be not so eco-friendly. If you’re using a humififier in wintertime, then you should get a humidifier that works by heating the water - you’ll be heating the house anyway, so the cost of the steam is free, essentially.
