Bruce Clark said [150206 MMDigest], "I am reluctant to use commercial
piano attachments that are supposed to automatically humidify or
de-humidify with automatic settings because they only add or subtract
moisture from one side of the sound board."

I disagree.  I find Dampp-Chaser humidity-control system works rather
well, if installed correctly.  The humidity does circulate within the
piano, and I've never seen an adverse reaction or soundboard damage
over the many years I've worked with them.

The biggest problem is the common lack of maintenance.  That is, the
owners fail to replace the evaporator pads and fill the water tank.

Phil Jamison