The Dampp-Chaser dehumidifier contains a glass rod, around which copper wire is wound. Although this is protected with an external aluminum tube, it is somewhat fragile. Moisture King dehumidifier rods are virtually indestructible, based on a design developed by the US Navy to keep moisture out of the sights for their big guns. Besides the standard aluminum tube configuration, they also make a flexible flat type that can be installed under the keys, between the front and balance rails. Unlike the glass rod, these can be literally tied in knots and continue to work just fine. They are somewhat less elegant in installation. Rather than the telescoping end segments to engage push-pins, they must be suspended on wires from mounting hooks. Moisture King's dehumidifier is lacking in elegance, superior in durability, and less expensive. I consider a humidistat to be an essential component to any humidity control system. Moisture King's humidistat include a dial control to adjust the cut-in/out moisture levels. They make a reasonable argument for the value of this adjustability in different climactic environments. Once you determine the best setting for your area, pre-set it, and remove the knob so the piano owner cannot "mess with it." I don't have enough experience with it to make a judgement on the merit of this feature, but I can say that it works as well as the DC humidistat, and is less expensive. The Moisture Kings system offers no humidifier component. They recommend a separate external room-humidifier. Frank Emerson
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