humidity variance

[Ted Sambell]

----- Original Message -----
From: "David Graham" <dcgrpt@earthlink.net>
To: <caut@ptg.org>
Sent: Thursday, May 02, 2002 8:54 PM
Subject: Re: humidity variance


> 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.
>