concert hall humidity

[Ron Torrella]

On Sat, 26 Nov 1994, richard west [U. of Nebraska] wrote:

> I am often asked by other institutions in the area if they should build a
> humidity controlled "box" in which to store their concert grand(s).  The
> concert hall is not humidity controlled so they worry about their
> expensive instrument falling apart.  But, if they do have a box for the
> instrument, what happens when the technician comes to service the
> instrument?  The minute it comes out of the controlled humidity
> environment, the piano is going to change.  So, to box or not to box, that
> is the question.

Hello All and Happy Holidays!

Several years ago, the Krannert Center asked Steve Manley for information
on how to go about setting up storage boxes for our concert instruments.
The two Steinways (one Hamburg and another NY) had, for many years, been
free-range pianos wandering the stages and backstage areas like so many
holsteins.  This, of course, left their tuning and regulation at the
mercy of the building's inefficient climate control system (one more thing
that's universal among colleges/universities!).  Steve's early design had
D-C rods hanging around the box (it's shaped roughly like a giant
fortpiano, 3-4' wider than the piano--one has a ceiling that's about 6.5'
high and the other has a ceiling that's probably 15' or so and both are
of concrete block construction with steel, uninsulated doors.).  The D-C
rods worked only moderately well on keeping the humidity in the 60-70%RH
range.  (I think it occasionally got as high as 80%RH.)  In the winter the
building attendants were given the task of making sure the room
humidifiers in each box was full.

More often than not, the humidifiers were left bone dry for several days
at a stretch.  Of course, this wasn't doing the pianos any good, so a
system was devised whereby the humidifiers had a copper line that ran from
the drinking fountain/piano cheek smasher just outside the boxes to the
humidifiers inside.  This seems to have solved the problem of thirsty
pianos.  Later, the D-C rods were replaced with a smallish (14"H x 5"W x
5"D) wall heater whose on/off cycle is controlled by a D-C humidistat.
The humidifier now operates in the same manner as the heater so both
units operate as a heavy duty humidification/ dehumidification system.
The humidity levels are manipulated such that the humidity cycles aren't
as wild as they once were.  The humidity appears to remain fairly
constant--withing the season--throughout the year, migrating from a low of
50% in the winter to a high of about 65% in the summer.  There are the
occasional times, of course, when things get a little out-of-control and
manual adjustments of the box climates is necessary.

Oh yeah, somewhere along the way, someone got the bright idea of buying a
hydro-thermograph for each box so we can watch the relative humidity and
temperature.  It's nice not having to swing that sling thing!

If anyone is interested in more specific info on the heater (the
humidifier is just your average water wheel with fan gizmo--'though I
think I may convince them to get one of those hi-tech Bionaire dealies to
eliminate the need for descaling the bugger every fall!) and/or the
configuration of both units, just rattle my cage.  I don't have the
specific information nearby....

I'm sure you realize that by virtue of their size, 9' foot pianos don't
react quite as quickly to changes in ambient humidity as, say, a
harpsichord.  Perhaps it speaks for the relatively good control we
exercise over Mother Nature at Krannert <flex, flex>, but I do not usually
notice a change in the tuning between the stage and the box.  In fact, I
will typically tune out on stage the day of a given concert--sometimes
morning, sometimes afternoon--then have the thing shoved back into storage
until showtime.  I generally check the piano about 15 minutes to an hour
before the house opens just to make sure a damper lead hasn't popped out
of an underlever or something crazy like that.  Unless someone has given
it a good thrashing in the meanwhile, the tuning usually holds up just
fine.


Ron Torrella                  "Dese are de conditions dat prevail."
School of Music                           --Jimmy Durante
University of Illinois