Where did the RH Go

[Bill Ballard]

I arrived to do a regular tuning on a Steinway M (1914 and all 
original) and which wanders quite a bit with the weather. The lady of 
the house had parked a room humidifier by the piano, and it was on 
duty for the first twenty minutes while I was there. My hygrometer, 
set on the corner of the piano farthest from the humidifier, read 
34%. When the unit went "off-duty" (where it remained during the rest 
of my time there) the RH promptly descended, finally stabilizing at 
22%. The temperature held steady during the whole time I was there.

It was a shock to me, because although I was ready to assume that it 
was the air in the room which contained the 34% RH, I didn't expect 
to see the RH dissipate so fast. This was an old New England house, 
nicely remodeled but not recently enough to include 
from-the-inside-out insulation in the walls (ie., no vapor barrier). 
The only part of that side of the room which showed evidence of 
moisture content migrating outside was the glass on the nearest 
window, where there was a small corner of condensation.

So where did the air's moisture content go? Apparently not through 
the walls, and the dissipation was far too fast for it to have been 
soaked up the the piano case and other wood surfaces in the room.

For me, this was a pretty good demonstration that moisture content 
needs as direct a path into the piano as possible, as only a Climate 
Control system installed directly under the board can do. Clearly, 
any moisture poured into the air surrounding the piano vanished as 
soon as the supply cut off.

Bill Ballard RPT
NH Chapter, P.T.G.

".......true more in general than specifically"
     ...........Lenny Bruce, spoofing a radio discussion of the Hebrew 
roots of Calypso music
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