The Yamaha HQ100 is a so-called “gray-market” upright. A gray market piano is one that’s authentically manufactured by Yamaha, but is not intended for sale in a specific geographic region or country. Instead, it’s sold as “gray market” — a market that exists outside of the official distribution channels and is not authorized by the manufacturer. In this case, the HQ100 is the Japanese version of the Yamaha MX100II, with a few small modifications.
Like all Yamaha Disklavier uprights, Dampp-Chasers cannot be installed inside the cabinet. There isn’t any room. Instead, a backside system is installed between the support posts behind the piano. The back is then ensconced in a light fabric to keep the humidity-controlled air inside.
However, the HQ100 has one significant oddity: There are only two support posts. The double bucket system usually installed just doesn’t fit. So in this case, after communicating with Dampp-Chaser, I opted to install a full-size bucket on the rear of the system. A thin layer of foam or neoprene needs to be pasted to the sound-board side of the bucket, and a full-size baffle needs to be installed, but otherwise the system is installed like a typical back-side system. The dehumidifier brackets did require some bending to get them to fit properly.
For the Velcro, I used two feet of two inch wide Velcro, with the male side backed with a strip of neoprene. The picture is below: