Dampp-Chaser Humidistat

[jpiesik@arinc.com]

     I've installed about a dozen D-C systems (full systems) mainly in
     grands.

     In a vertical the humidistat hangs lower than the dehumidifier rod and
     is usually positioned about 4-6 inches from the end of the humidifier
     tank. OK, that's pretty straight forward, not much room for
     "interpretation." I use the 50W rod in a vertical piano along with the
     complete system.

     For grands I typically use at least 2 25W rods under the soundboard, 1
     50W rod where the keybed meets the open soundboard space, and 1 35W
     rod under the keybed. I place the humidifier tank as close to the
     centroid of the soundboard as I can approximate it. Mostly I hang it
     under the beams, unless the client objects, then between the beams. So
     far so good . . . now the humidistat placement.

     In a grand installation, there is more "discretion" that the
     technician can use in the placement of the humidistat. (The
     instructions, unfortunately, are not complete and clear about the
     humidistat placement.) I shoot for 5-6 inches from the end of the
     humidifier tank. However, this sometimes requires placing the
     humidistat VERY near a dehumidifier rod. Since in grands the
     humidistat "window" is above the dehumidifier rods (as opposed to
     verticals where it is below), and heat rises, is there a detrimental
     effect when placing a humidistat close to a dehumidifier rod? How
     close is acceptable? Does it matter? Sometimes, the final placement of
     all elements of the system tend to end up with the humidistat very
     close to a dehumidifier rod - at least for some of my installations.

     I ask the D-C experts of this list what do YOU look for when
     "designing" your installation and placement of the humidistat in a
     grand piano? How far from the rim, from dehumidifier rods, and from
     the humidifier tank provides an optimal placement of the humidistat?
     And, how do you determine how much drying power (wattage) to put in
     the piano?

     Any discussion regarding the installation of "crippled systems" (as I
     call them - Dampp-Chaser installations minus the humidifier) might
     also be interesting.

     Thanks to all!

     John Piesik
     San Diego Chapter PTG
     JPIESIK@ARINC.COM