Humidity Factor, workload

[Jeff Tanner]

Fred,
I think the Guidelines would be incomplete without an explanation of the
climate factor, and perhaps the other factors as well, like you have
written below.  Your explanation and comments are quite important to
understanding the formula.  A "Very Poor" factor of .4 equates to
increasing the workload by 2.5 times over the "good" climate factor and 3
times the "excellent" situation, and I think it should be explained to
administrators who read the document how this is derived and what these
numbers indicate.

I agree with you that these numbers may be conservative, but I think it
would be difficult at best to come up with an accurate calculation of
exactly how much climate changes affect workload.

Is there a need for one more variable level, or at least including into an
existing variable description, the situation which you describe in your
General note and can be best described as "frequent deep cycling of
humidity"?  I had two occasions this semester of humidity cycles in excess
of 30% within a period of less than a week -- that's up, down, and back up
again, or vice versa.  Rapid cycles of 15 to 20% were even more common,
while a change of 12% can commonly happen between 8 am and recital time
(4:30 - 5 pm).  I did not take measurements every time, so it is entirely
within reason that there were more frequent occurrences of these changes.
This, in my "humidity controlled" recital hall, where the pianos get daily
checkups, demonstrates the effects of the "modern HVAC system" and just how
difficult it is to control.  There's no way to keep the 125 pianos in the
building tuned with these kinds of frequent changes going on, perhaps even
with 5 techs tuning constantly, so we have to accept a certain level of
"out of tuneness".  Yes, quality of service is affected by climate.

56% of respondents (48/85) in the 2001 CAUT survey described their climate
situation as either "poor" or "atrocious" (evenly split), so I know I'm not
the only one experiencing this.

I did have one "control" piano this year (well, sort of).  We lost a piano
faculty member last year who wasn't replaced, and an opera coach used that
studio this year, which has two S&S B's both purchased the same day, 7
years ago.  Both have full Dampp-Chaser systems which are maintained
meticulously.  He rarely used the 2nd piano, if ever, and I didn't tune it
from last April until this April.  He apparently used the 1st piano daily,
and the tunings changed wildly between my visits (the frequency of tunings
varied).  However, the 2nd piano was MUCH closer to pitch than the 1st when
I came in to tune them both in April for a piano competition.  I expected a
major pitch adjustment on the 2nd piano and found only a touch up was
needed, while the 1st piano was the one which needed the pitch adjustment,
having only been tuned 6 weeks earlier (roughly the same RH levels, 31%,
34%, both dates, respectively).  This room experienced a change from 62% RH
on 4/25 to 34% RH on 4/26, indicating the severity of deep cycling.

Therefore, by this simple example, it would appear that climate and usage
combined together make a much larger impact than simply climate alone.
Something we already knew, but this supports it.  It also may reveal the
limitations of the Dampp-Chaser system's effectiveness in an environment
with "frequent deep cycling of humidity".  It also may indicate that more
frequent tuning further exacerbates climate/usage induced pitch
fluctuation, if not certainly playing a role equal to that of usage.  In
other words, the harder you work to keep them in tune, the more work you
potentially create for yourself in this type of climate situation.  Kind of
like trying to climb a mountain standing in quicksand.  So again, we have
to learn to live with a level of "out of tuneness" regardless of how hard
you work at it.  Yes, there is a flaw in my "study" in that no, I didn't
check the tuning of the 2nd piano during the course of the year.  But did
that matter since the piano wasn't in use?

My thoughts,
Jeff


>Notes with respect to piano installed humidity control systems:
>1) It is likely that a complete system without back/bottom/string covers
>can bring a piano into the Excellent category if the variance in the
>building is no more than 30%. Some discretion should be used in
>assigning categories.
>2) "Half systems" (a humidistat with a dehumidifying unit) can help in
>situations where ambiant humidity rises above 50% on a regular seasonal
>basis. In general, such a system might improve tuning stability by one
>step. Complete systems are strongly recommended wherever possible under
>most conditions where humidity varies more than 15%.
>3) There is a certain amount of maintenance time involved for complete
>systems. Most of this maintenance is unskilled, and can be accomplished
>by, say, a work study student, thereby freeing up technician time.
>4) Systems must have the appropriate wattage and position of components,
>as recommended by the manufacturer, to produce the predicted level of
>effectiveness.
>
>General note with respect to humidity control:
>	Variance in humidity is by far the largest factor in maintaining tuning
>stability, and it has structural effects on the long term integrity of
>every piano (particularly soundboards and pinblocks). The effect of
>humidity variance is amplified many-fold in modern institutional
>environments, due to code requirements for HVAC systems. Modern HVAC
>systems exchange the entire volume of air in the building many times a
>day. As a result, air is in constant motion (leading to more rapid
>movement of ambiant humidity to and from wood), and changes in outside
>humidity are reflected almost instantly within buildings.
>	Hence, the importance of humidity control to the quality of piano
>service cannot be overemphasized. In all likelihood, the multipliers for
>"fair" through "very poor" are very conservative, in terms of showing
>the effect of large scale humidity change on overall tuning quality and
>general long term need for rebuilding and replacement of instuments.
>
>As always, comments and suggestions welcomed and solicited.
>Regards,
>Fred Sturm
>University of New Mexico


Jeff Tanner
Piano Technician
School of Music
University of South Carolina
Columbia, SC 29208
(803)-777-4392 (phone)