HVAC

[Jeff Tanner]

Hi Chris,
You wrote:
>- If we install the proper equipment, the building walls have no
>vapor barrier and therefor any increased humidity would simply go
>through the walls and outside.  This would cause steel girders to
>rust and the mortar in the brick to breakdown and actually stain.
>(called efflorescence, for vocabulary buffs)
>
>- Ditto for the roof.

I think I'm gonna call "BS" here.  What is your indoor RH during the
summer?  and why would the effects of high summer RH on the steel girders
and mortar be any different from trying to bring winter RH up to 42%?

>Do any of you have a newer building with state of the art HVAC?  What
>are the results?  Is it worth the work?  Will it actually help or am
>I howling in vain?

New building, but someone over at the budget and control board looked at
our request for humidity control and apparently vetoed it as if a luxury,
when the building was being planned. The building committee did not learn
it had been cut until it was much too late in the building process.

Protecting a $2.9 million replacement value of pianos is a luxury.  And we
were actually under budget and had more than enough funds left over to have
installed the proper system.

We have since added humidification abilities to the building, but it is
highly inefficient and I'm on the phone with the HVAC services about once a
week trying to get them to make the system do what it's supposedly designed
to do.  We currently have the threshold set to add humidity when the RH of
return air drops below 50%.  When I got back from Christmas Break, I had 72
degrees and 42-45% in every room I measured.  Starting the next Monday, the
RH dropped to the high 20's.  Last week it was 25% RH in the building, and
today, with the coldest night in over 20 years behind us and the day off
for snow yesterday (yes, in Columbia, SC), I'm getting RH readings of about
32%.  Next week we should return to normal, which will mean RH
rollercoastering from around 35% to 48%.

So, apparently our add-on humidifiers can't handle the job.  We are
constantly replacing the sensor in our recital hall, and I'm thinking our
current problem is because the sensors in the rest of the building aren't
worth the box they're packaged in.

We can't do much about high RH.  4 of my pianos are in areas which have
dehumidification.  The other 121 are not.  Our air handlers do not have
"re-heat" and so dehumdification can't be added until that's there.  I'm
trying to learn what that would cost so I can make a proposal to someone.
But I suspect even if we got it added, it would be about as efficient as
our humidification ability.

Another part of the equation your consultant did not address is the Federal
requirement for constant exchange of outside air, and how that magnifies
the difficulty in managing RH.

I must say, that with this RH rollercoastering, it gets very difficult to
get motivated to go tune a piano you know will be badly out of tune again
within 3 or 4 days.

My thoughts.
Jeff

Jeff Tanner
Piano Technician
School of Music
813 Assembly ST
University of South Carolina
Columbia, SC 29208
(803)-777-4392
jtanner@mozart.sc.edu