heater bar question

[Don]

Hi Terry,

My rudimentary studies show that on average the pitch at A4 will change by
.75 of one cent for each 1% change in humidity level. These measurements
were taken on 2 different pianos both of which were small upgrights. 

If the piano was 22 cents sharp at A4 then humidity has gone up by about
30% since the last tuning. I never install just a partial unit for my
climate requires both. If your client has forced air central heating I
would install a complete system. The difference in price would be paid for
by a single extra tuning being needed.

I suggest that the piano be completely and carefully tuned one month after
you have installed the partial unit.

Consider a plastic back cover for the instrument. It will improve the
performance of the system by about 4X in my experience. 

The damppchaser rule of thumb is one watt of dehumidifying power for each
1% of humididy drop desired. So given a 30% increase in humidity level (and
we are not at mid summer yet) I would recommend a 50 watt rod.

At 09:45 AM 04/07/2001 -0700, you wrote:
>Howdy all,
>
>A customer posed a rather interesting question regarding a heater bar.
>I was there to tune his acrosoic, and noticed that in the past 6 mo. since i 
>tuned it last, that the pitch had gone 22C SHARP! So after explaining the 
>"pitch adjustment" procedure, and cost (1/2 my tuning fee), I proceeded with 
>the tuning. After i was finished i recommended a Heater bar & humidistat, 
>since he lives so close to the beach, higher humidity is the only real 
>concern, and that a heater bar placed inside his piano, with a humidista, 
>would keep his piano much more stable, and far less prone to excessive pitch 
>fluctuations. He gladly agreed; But then a thought came over him and he 
>asked: "Since you tuned the piano to normal pitch, at the present higher 
>humidity, isn't it likely that it will go flat after the bar is installed 
>and removes the excess moisture?" Hmmm, good questio, I thought. He didn't 
>really seem too worried about it, but just wondered, so I said that in the 
>week or two that it'll take before i get the bar & humidistat here and 
>installed, the pitch will likely "creep" up a tad, so it should all balance 
>out. I did tell him that if he notices any errant notes that may go out 
>within a month or two that i would come back and smooth them out, no charge. 
>Just wondering how any othe list members would've handled this matter. 
>thanks!
>
>Terry Peterson
>Precision Piano Service
>Torrance, CA
>
>_________________________________________________________________
>Get your FREE download of MSN Explorer at http://explorer.msn.com
>
>
>

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

Tuner for the Saskatchewan Centre of the Arts

mailto:drose@dlcwest.com
http://donrose.xoasis.com/

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