I like the older GeneralAire drip through humidifiers.
No standing water in the unit.
No heating coils or energy draw other than 24vac to open a solenoid.
Other than the water solenoid, no moving parts.
Replace the pad that the water runs through once a year.
Simplicity at its best....
link
Model 1042LH - Legacy Series Humidifiers - General Filters, Inc.