We once tried to use a couple of cheap humidifiers.
They were ultrasonic and vibrated a piezoelectric element to make mist..
Before the end of winter, we found a layer of very fine micro-dust on
everything electronic in the house. TV sets parts were heavily coated with the white powder..
We were collecting a lot of that powder in our lungs! Not recommended,
unless you have well filtered or maybe distilled water.
We have a different model now.. Not cheap, but it works pretty well.
Vornado Evap3 1.5 gal. Whole Room Evaporative Vortex Humidifier-HU1-0034-06 at The Home Depot
When it's really dry, we run it in the living room.
But, it's been so wet around here during the winter, we haven't used it this year or last..