I used for a while a Holmes cool mist ultrasonic humidifier that needed no filter.
It broke after a while and I could get a refund.
Ultrasonic cool mist is a visible tiny spray of water. It was a bit too directional to cover enough, but it looks like it made the vandaceous plants hanging bare root happy.
I am curious about a warm mist. Maybe it would increase the actual humidity more but I noticed those warm mist humidifiers are 300 W so they use a lot of electricity.
Also some cool mist ones use filters that are quite expensive to replace.
I would check online for reviews of specific models.
Probably if cost is no issue I would get a warm mist one or an expensive ultrasonic cool mist.
In the long run it could also contribute to mold. would run it on a timer and then run a fan for a while.
Actually wish I had an humidifier now. feels really dry in my bedroom.
if you have plants in the bathroom you could run the hot shower for some minutes and you will get high humidity