Humidity control (disagreemt)

[BobDavis88@aol.com]

My thanks to Bill Bailer, Eric Leatha, and another technician who responded
privately for pointing out that I took a shortcut I shouldn't have taken.

from Bill Bailer:
<<Bob,
I know what you mean, but I would like to point out a possible
implication which may be a cause of misunderstanding:

It is my experience that pianos that are in truly unheated environments,
such as unoccupied summer homes, stay in tune extremely well, and drift
much less than those in heated buildings.  In the case of the churches
that you describe, I suspect that they actually are heated at least part
of the time--  such as Sunday morning at the least.....>>>

and from a private reply:
<<The piano was moved to...(about 1,000 miles) and then to... (about 350
miles). I went to visit and the piano had not been
tuned for 4 years because no one was willing to make the trip to....
You can imagine my surprise when the pitch at A4 was 0.3 cents flat!

At least for uprights properly installed DC systems with enough
dehumidifying power and good wicks one tuning a year can be enough. >>
-------------------------------------

When I spoke of "unheated churches" I should have mentioned that they were
also "uncooled churches", and that we have seasons which are backwards from
many others throughout the country. That is, our summer is very hot and dry
(NO rain), and our winter is cool and rainy. And you're all correct that this
causes two tuning problems rather than one:

1. day-to-day - tune the piano during the week when the temperature is 50
inside the building and the humidity is very high, and when the heat comes on
for the Sunday service the pitch drops like a stone, thus the importance of
having the building HVAC on and stable before and during the tuning.
2. season-to-season - Leave the piano alone year-round in my part of the
country, and it experiences 50 degrees and wet in the winter and 85-90
degrees and very dry in the summer, and the pitch, while not moving as much
as in the climates with wet summers and cold dry winters, still moves a
significant amount.

The last point is subjective - how close is acceptable. My experience is that
a freshly tuned piano has audibly closer tolerances than a humidity control
system can maintain over the course of a year, but I'd be interested in the
experience of others in various parts of the country. Can you really maintain
+/- 0.3 over the whole piano for a year? I've had the pitch change a couple
of cents while I was tuning as the system cycled. Also, (my experience only)
a piano whose A4 moves a cent (which would probably be audibly tolerable) has
moved enough in the tenor to have audibly wrinkled octaves. Admittedly, while
theoretically there shouldn't be a difference between concert and home work,
realistically the average home pianist will tolerate more drift than is
appropriate in a performance setting.

Bob Davis, RPT