David Sanderson, Excellent point. Thank you for bringing it up. It gives me the opportunity to at least touch on something that I frequently get calls about. The objective is MAKE THE PIANO STABLE. This can be at 38%. It can be at 48%. If the piano becomes acclimated to even higher or lower humiditys when new, RH levels higher than 48% or lower than 38% are likewise satisfactory SO LONG AS THEY REMAIN CONSTANT. On the higher side, you want to be careful about getting to the point of sluggishness or rusting . The same kind of thinking applies to going too far on the low side. I don't know that there is anything sacrosanct about 42% except that it is the point at which some manufacturing operations take place when the piano is built. CONSISTANTCY IS FAR MORE IMPORANT THAN ATTAINING A SPECIFIC RH LEVEL! So long as there is at a reasonable level. This next section is something I wrote a number of months ago for a different purpose but it seems to answer the why of controlling at different humidity levels, so I provide it here: A piano owner moves from Miami to Llas Vegas. Her grand has not been protected from Florida's humidity accept as provided by home air conditioning which at best has produced an environment of 65% RH. It has developed a sense of belonging in a wet environment. It works but not really well. She is used to it, however, and gets by. It is a good piano and she is concerned about how the las Vegas dryness will affect it. Her technician describes the Dampp-Chaser Humidity Control System and she approves the purchase and installation. Now he has an option. He can purchase a humidistat that will cycle to produce an average 38% RH ( a dry H-2) 42% RH (the standard H-2) or the 48% RH ( the wet H-2). He selects the wet H-2 at 48% because he wants to produce a constant RH level, but create as little change from the old environment as possible. A piano going from the northeast to New Orleans might be handled the same way. Several technicialns living in "dry" areas have made a practice of buying dry H-2's because they want to control but they want to humidify as little as possible . In every area af the country where there's a predominent humidity level, you can make a strong argument for using either a wet H-2 or a dry H-2. That is why we have begun to provide them. Bob Mair, Dampp-Chaser Electronics
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