Hi; For the last 4 years ,I've used a cheap drugstore type ultrasonic humidifier and i'm perfectly happy with it.Even when I shorted it out by getting the base wet,all it needed was a new fuse (75 cents)and it is still working.I should mention that I run it only when the lights are on,and I have modified the fog output vent with a plastic 'tent' ,so the mist is hitting the mounted cool growers( Pleurothallis,Lepanthes,etc.), and they love it.
So you see, you dont need to humidify the room,only the growing area. However 60 % humidity is good, especially with good air movement.
In closing
nly get a humidifier if you grow mounted cool growers that like foggy,mossy conditions, and point the fog at them.
Good luck.