[CAUT] temperature and pitch

[Jeff Tanner]

Today, I tuned a Kawai KG70 with a D/C installed. During the hour and a half 
I was there, I felt underneath several times and did not feel the 
dehumidifiers ever come on.  They never needed to with RH at 41% outside the 
piano and 42% inside. Temp under the lid - in the dark - was 73.5 and the 
temp on the table next to the piano was 73.0, bright lights in the room, 
etc.  That's half a degree.

My thinking was more like how your house stays warm at night, despite a 30 
degree drop in outside temperature. You get the walls warm during the day 
and the heater running inside keeps it warm on the inside while the outside 
air temp changes dramatically.  Yes, its a little different in that with a 
house you have circulated air and a thermostat maintaining the inside 
temperature, but the same idea in that you have somewhat of an insulated 
cabinet keeping the inside temp from being affected as much by the outside 
air changes.

Jeff

----- Original Message ----- 
From: "Fred Sturm" <fssturm at unm.edu>
To: "College & University Technicians" <caut at ptg.org>
Sent: Wednesday, December 16, 2009 7:34 PM
Subject: Re: [CAUT] temperature and pitch


> On Dec 12, 2009, at 12:52 PM, Jeff Tanner wrote:
>
>> Yes, your D/C system was operating all along, which is why wonder if  the 
>> inside of the piano was affected as much by a 10 degree change  outside.
>
>
> Today I tuned a Steinway B with a double tank D/C system installed.  It 
> has an undercover, and the lid was closed (covered with Christmas 
> decorations) and stayed that way while I tuned it. I placed my Mannix 
> CMM880 thermo-hygrometer on the plate as far as I could reach. It 
> measured 70.3F. I placed it on a table next to the piano. It measured 
> 71.0F. I repeated a couple times while tuning to be sure, leaving it  in 
> each location for several minutes. No mistake.
> I'm guessing the D/C rods did not add significantly to the  temperature of 
> the plate. I don't think there is any real significance  to the piano 
> being cooler - probably something to do with heating  system cycling, and 
> the air inside the piano being static. But I think  my earlier assessment 
> was correct: the D/C produced heat was not a  significant factor.
> Regards,
> Fred Sturm
> University of New Mexico
> fssturm at unm.edu
>
>
>
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>