Damp Chaser in old upright

[Farrell]

I don't understand much of what is in your post. Please explain. Comments
interspersed below:

----- Original Message -----
From: "Tony Caught" <caute@optusnet.com.au>
To: <pianotech@ptg.org>
Sent: Saturday, July 07, 2001 10:15 AM
Subject: Re: Damp Chaser in old upright


> Hi Judy,
>
> Our weather conditions seem the same (humidity range) but right now we
have
> had a dry spell. I have been fitting Dampp-chasers for ten years now,
> started of with the humidistat's set at 42% and 25W rods to today's
> Humidistat set at 55% with 50W rods.

So it sounds like we are installing the dehumidification portion of the
Damp-Chaser system? Keep in mind that you need to monitor inside RH to be
sure that is an appropriate installation. That is what I do here in Florida
(although I use a dry calibration humidistat).

> The 25 W / 42% system stays on all through the "wet"  which means that the
> internal RH was most likely about 55% and then dries the piano out to 42%
> RH, then when the dry dry spell comes in, it all dries out too much.

I disagree. If the 25W / 42% system stays on all through the "wet" season,
it means that the RH inside the piano is somewhere between 43% (if the
humidistat is performing as designed) and 99% - where do you get 55%? If the
system is on all the time, presumably it does NOT get the piano interior
down to the 42% (or wherever the device would turn off the power). Then when
the dry dry spell comes in it may indeed dry out too much (what does your
inside RH go down to during the dry period?) - but not from the heater rod -
if your humidistat is functioning properly, it turns the heat off when the
RH of the piano interior gets down to 42%. The Damp-Chaser system will NOT
lower the RH any more.

> The dry
> spell only lasts for about 3 weeks but that's enough to dry the piano out
> too much.

How dry is dry - in the home interior. Gotta take into account heating of
home.

> The 50W / 55% system does switch off and on even when the RH is over 80%
but
> does not dry the piano out to the 42% mark, it stops at 55%.

Have you measured that? The fact that the system switches on and off, means
that the system is properly sized to reach the RH at which the humidistat
turns the system on and off. The system will now keep the RH stable in the
piano interior when the room RH is at or above the RH at which the
humidistat turn on and off - presumably at 55% (you might be surprised if
you measure).

> Now what
> happened when the dry snap came in was to dry the piano out to 40% which
is
> acceptable whereas with the other system, it dried out to say 30% which is
> of course, to dry in comparison to the upper limit.

No way. Not if your humidistats were installed properly and functioning
properly. The 42% humidistat will not be part of a system that will dry the
piano out to less than 42%, and the 55% humidistat will not be part of a
system that will dry the piano out to less than 55%. That is what
humidistats do!

>
> I have always figured that if you can keep a piano to within a 20%
humidity
> swing, it will survive reasonably well. So go for a "wet" 55% humidistat
> with a 50W rod in your area.
>
> Tony Caught

I do not agree. I say if the interior room RH does not dip significantly
below 40% (like here in Tampa), consider using a dehumidifier-only system.
Use a humidistat that will turn on-and-off as close to the 40% figure as
possible (the standard calibration SHOULD be proper - but you may wish to
measure them yourself - I have and I now use the dry calibration
humidistat). Use enough wattage in your rod(s) to make the system turn off
(at least for short periods) during times of high RH.

Terry Farrell

> ----- Original Message -----
> From: jstuart1 <jstuart1@pdq.net>
> To: <pianotech@ptg.org>
> Sent: Saturday, July 07, 2001 10:46 PM
> Subject: Re: Damp Chaser in old upright
>
>
> > Thanks Clyde. I ommitted my first name because I am not sure how
everyone
> accepts female
> > techs. When I was into electronics (pinball machines) it was my
experience
> that if I
> > posted my name, no one would reply but if I just posted JStuart everyone
> thought I was
> > male and would answer my questions. My name is Judy. Usually the
humitity
> here is
> > houston runs between 40 and 100% There are very few days where it is
less
> than 50 % and
> > on average I would guess 70-80.
> >
> > Judy
> >
> > Clyde Hollinger wrote:
> >
> > > JStewart (a first name would be nice),
> > >
> > > A piano equipped with an uncontrolled heat rod could be worse off than
> having no
> > > humidity control at all, depending on the humidity of the Houston
area.
> At the very
> > > least it should have a humidistat to shut it off when it gets dry
> enough.  These are
> > > available from Dampp-Chaser.
> > >
> > > All of us were beginners at one time.  Hang around this list, go to
> conventions and
> > > you'll learn a lot!
> > >
> > > Regards,
> > > Clyde Hollinger
> > >
> > > jstuart1 wrote:
> > >
> > > > I believe this piano has just the heating rod. I am in Houston so
the
> humidity
> > > > here runs from the 40's to the 100 range. I don't believe the bar is
> on any sort
> > > > of timer or other control and the owner indicated that it stays on
all
> the time.
> > > > I am not sure what the rating of the rod is.
> >
>