humidity variance

[David Graham]

Though hesitant to fill up everybody's mailbox with another message, I do
want to comment about this. At NIU we spent over $250,000 a couple of years
ago to install a digitally controlled humidity control system. The range of
variance is around 15% from Sept to May. The system is not digitally
controlled when the air conditioning is on, but the wall and duct sensors
are still on, so the heating plant personnel watch them and super-cool then
warm up the air when the humidity gets too high. This has worked very well,
particularly since there is very little going on during the summer, so it
doesn't really matter if the humidity gets up a bit. I just make sure it is
brought down to no more than 45% before I start tuning for the fall
semester. The amount of tuning now needed has dropped drastically. I tune
the studios no more than twice a semester, and they are always on pitch and
generally in tune with themselves. Since we started improving the actions
with Stanwood Touch designs, the main complaint of the piano faculty is that
the students are practicing on pianos in better condition than they had when
they were students. I thought I might have to spend a lot of time watching
the heating plant personnel to make sure they would do their job, but they
have been great. I made two calls over there last year, and one was to find
out when a broken part for the system would be replaced. As soon as it was
repaired, the pianos in that area became very stable again. Before this
system was installed, the range of RH was 15 to 80%. 
      I have another institutional client (Sherwood Conservatory in Chicago,
where David Stanwood will be teaching an all day class Wednesday during the
convention). They have Dampp-chasers on all of the studio pianos. They
reduced the amount of tuning needed by half. We hope to add undercovers on
most of them next year, but a part-time maintenance man checks and fills
them each week from Sept to May. (They are the older kind that can unplug
the low water light.) 
     My experience in the Midwest is that controlling the humidity has a
PROFOUND effect on the workload, but I wonder if that would be a universally
quantifiable. Areas with more stable climates would not likely show as great
an effect.