In comment 14284916
| (or something like that) for that purpose when I looked into this, but that was about 15 years ago. If you have a humidifier in the house, shouldn't that suffice?
I think that may be our system as well. Installed and maintained by our technician (aside from refilling).
The question about room or house humidification is a good one. To be honest, I tend to let those systems lapse a bit here and there. The one built into the piano is not necessary if you can be counted on to keep the room in good shape. I could not. For me, it was helpful that every time I walked by the instrument, the LED was either red or green, and for whatever reason, I was motivated more by protecting the instrument than by keeping the humidity in the house at some level.