DC

[Don]

Hi Jonathan,

I wonder what would be the "billeable hours" for a trip to Antartica to
tune that piano? *grin*

In fact in the Grand Cayman Islands the temperature variation is less than
2 degrees F. in a 24 hour period. They also have exceptionally stable
humidity. It's the only place on earth that I know of where a DC system
would perhaps not be useful in improving stability.

I have my fair share of "agressive" clients. Included is a teaching studio
with two matching 6'9" Kawai Grands. These pianos get played *lots*. They
don't vary more than 2 cents at A4 on a yearly basis. Our climate is -40 C
to +40 C every year--with humidity going from 4% to 84% according to
Environment Canada.

Humidity goes into wood faster than it out gasses out. I'm sure that when
it rains where you are that indoor humidity levels *spike*. This is enough
to smear unisons and to affect the bass break area, even if humidity goes
back down later. Unisons are such fragile things.

I have also seen pitch *rise* in a dc equipped piano by 14 cents at A4 in a
similar number of hours. This was in the pre bottom cover days. The
instrument was a large Steinway Grand. It had been left unplugged for about
several days.

Pianos are wonderful devices for measuring humidity change. I'd love to
have a Dickenson Data logger or other truely accurate measuring device to
track this.

Do you have many clients who have damppchaser systems, with bottom/back
covers?

I do appreciate your showing us the skuttle approach. It would not work
where I live, unless the rest of the home was specially engineered for such
high humidity levels in the dead of winter.

At 10:46 PM 2/13/2003 -0700, you wrote:
>
>I do have a friend working at a facility in Antarctica, if you'd like to
>email him about temperature and humidity differences between high and
>low sun.  I'm not sure they have a piano there though.
>
>Admittedly, I don't document things as well as I should sometimes.  I
>don't recall what the smallest variance has been.  I know that with
>nothing, the piano will suffer 20-30 cents every 6 months, sometimes
>more when the fall transition happens, and the heaters come on.  Since
>most of my customers play their pianos a lot, I don't know that I have
>anyone who's piano stays within 2 cents.  Many of my customers are, or
>have been performance students.  They tend to play a little harder than
>the average 6 year old, and for hours a day.  What I mean to say with
>this, is that while I haven't measured it, I'm sure their pianos vary by
>more than 2 cents a year.  I don't know that I've ever seen a regularly
>played piano that would stay within 2 cents in 12 months.  No matter
>what the environment.  Of course I could be wrong.  :)
>
>I have kept track of RH levels though, and know that the unit keeps
>things in what I would consider (at least for this environment) an ideal
>range.  Different pianos react differently in different situations, so
>I'm not sure that your question is a fair one.  But like I said, I have
>kept track of RH levels, and this is what I'm most concerned with.  The
>stability it provides is seen in the way the piano holds up.  But that
>stability is completely relative to it's stability before it's climate
>was controlled.
>
>
>
>
>Best Wishes,
>
>Jonathan Finger RPT
>
>
>
>-----Original Message-----
>From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On
>Behalf Of Don
>Sent: Thursday, February 13, 2003 11:20 PM
>To: Pianotech
>Subject: RE: DC
>
>Hi Johanthan,
>
>I'm glad the sun shines at night in your location! *grin*.
>
>Have you documented piano stability of less than 2 cents on any note
>over a
>one year period with these units? 
>
>At 08:25 PM 2/13/2003 -0700, you wrote:
>>Well for one Greg, all but the high end April Air units are based on
>the
>>"water wall" method.  I'm not saying that it doesn't work, however it
>>isn't the best solution for the environment here.  Temperatures might
>>get cold here, but we also have 300 days of sunshine a year.  Couple
>>that with a mile less atmosphere between us and that sun, and you have
>a
>>pretty intense heat source.  Even if the temp is below 30 degrees
>>outside, the sun itself is very warm.  With this kind of intense sun, a
>>houses heater might only run a couple of times during the day here.
>>
>
>Regards,
>Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
>
>mailto:pianotuna@accesscomm.ca
>http://us.geocities.com/drpt1948/
>
>3004 Grant Rd.
>REGINA, SK
>S4S 5G7
>306-352-3620 or 1-888-29t-uner
>_______________________________________________
>pianotech list info: https://www.moypiano.com/resources/#archives
>
>
>
>_______________________________________________
>pianotech list info: https://www.moypiano.com/resources/#archives
>
>

Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.

mailto:pianotuna@accesscomm.ca
http://us.geocities.com/drpt1948/

3004 Grant Rd.
REGINA, SK
S4S 5G7
306-352-3620 or 1-888-29t-uner