DC Study - was Another heater bar without a control...

[Isaac OLEG]

I believe that any DC system installed may be well dimensioned in
regard of the conditions of the room, the piano type, etc.

I have a very precise electronic R.H. tester (0.1 %precision with
external gauge) and I remember that I checked a simple 30W element in
a little Yamaha 108 vertical, that I installed in a very moist place
under the house.

I came back 1 month later and checked inside the piano and in the
room. The heater was permanent for this test, and , probably because
no air flow in the piano and not enough power, the R.H level was AT
THIS TIME higher in the piano than in the room (63% in the piano while
58% in the room if I remember correctly).
I was very surprised, but I believe it was only because the room had
been opened, or it was in a more dry time, and the piano did not have
enough time yet to stabilize to the dryer climate. But it was evident
then than the heater element was not strong enough for this case.

Of course that does not mean the system, if correctly dimensioned,
would not work, but if the humidity is too high, having not enough
heat in the dehumidifiers will may be create more hot warm air than
dry one.
I believe too that there may be a relation with the flow of air, if
the same air is recycled always in a somewhat close environment, I
can't see how the moisture can go out. It have to swell thru the
parts, the felts, the case, so may not it be necessary to have some
apertures to allow for air circulation ? (not sure at this one)

I installed recently a 3 bars system in a 68% place under a little
grand, and indeed 1 hour after plug in, there was a nice 43% place
just under the soundboard

A chart with information on how much temp/R.H may relate with how much
power (in Watt) could be very helpful for choosing components.

Any thoughts ?

Regards.

Isaac OLEG
France
Well tempered climate (not tuning!)

> -----Message d'origine-----
> De : owner-pianotech@ptg.org
> [mailto:owner-pianotech@ptg.org]De la part
> de G GRAVINA
> Envoye : mardi 30 juillet 2002 12:45
> A : pianotech@ptg.org
> Objet : DC Study - was Another heater bar without a control...
>
>
> Matt W wrote:
>
> >I would be willing to participate in data collection with you
> >Jerry.  Although I sound pretty biased against this
> hardware,  I can be at
> >once skeptical and at the same time open-minded.  In my
> opinion, any study
> >should involve at least one pair of pianos - one for the
> hardware and an
> >"untreated" piano as a control.  The pianos should also be
> left untouched,
> >so as to avoid any data contamination through tampering.
> Unfortunately, I
> >don't know of anywhere where this condition exists, except
> maybe for a
> >store with a storage facility, which might involve rental
> and storage fees.
> >
> >Gotta keep it interesting
> >
> >Matt
>
> Folks,
>
> If one were to set up such a study, what other parameters,
> controls,
> frequency of data collection, length of study, etc., should
> be considered?
>
> Jerry Gravina, RPT
> Babylon, NY
>
>