Different question about heater bars

[Farrell]

Hi Clyde. "I'm pretty sure I heard a Dampp-Chaser representative say getting
enough dehumidifying power is a challenge as it is." I wonder if you could
expand on this. I am very interested. I commonly put MUCH more wattage than
I commonly see recommended in my installations. I have 200 watts under my 5"
10" grand, of course controlled by the humidistat. After much monitoring, I
found that with only 100 watts installed, if the room humidity was up around
75% RH, the system would never turn off (I have a dry calibration humidistat
that turns on and off around 48% RH) and RH would decrease to around 55%,
but not lower (I have monitored the performance of at least 10 regular
calibration humidistats and  I have observed them usually cycling on and off
around 55 to 65% RH). I upped the wattage to 200W and now even with a room
RH of 75%, the RH under the soundboard will go down to the upper 40s RH and
the system will cycle on and off. There should never be a problem with lots
of power (of course, no need to put more wattage than needed for the desired
RH drop) IF the system is controlled by a humidistat.

If the dehumidier does not turn off, the system is underpowered for that
humidistat calibration. Put the hydrometer inside the piano at the
humidistat to monitor the system performance. It's educational. Also, it
helps to plug a 120 Volt clock into the same humidistat outlet as the heater
bar to monitor system cycling.

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Clyde Hollinger" <cedel@supernet.com>
To: <pianotech@ptg.org>
Sent: Wednesday, October 18, 2000 7:32 AM
Subject: Re: Different question about heater bars


> Mike,
>
> Yes, it should be unplugged in the winter.  I agree with the other
responses that
> a humidistat is highly advisable at the least.  It will sense whenever the
> humidity is too high and snap on  and off automatically.  Without the
humidistat
> there is no control.  What happens if you have low humidity for a week in
the
> summer?  It adds to the piano's stress by lowering it more than it should.
And
> during fall and winter months there can be a warm wet spell, but the
unplugged
> heat bar can't help correct that.
>
> Another problem is that people forget when they are to pull the plug, or
they get
> things switched in their minds and pull the plug in the summer and plug it
in for
> the winter, which exaggerates the humidity swings in the piano.
>
> In my mind, especially critical is the strength of the heat bar.  I find
pianos
> with little 15-watt bars from time to time.  I doubt they can do as much
good, or
> damage, as the current 50-watt bars.  I'm pretty sure I heard a
Dampp-Chaser
> representative say getting enough dehumidifying power is a challenge as it
is.
>
> Regards,
> Clyde Hollinger
>
>
> MBrat70179@AOL.COM wrote:
>
> > Hi list
> >
> > Let me preface my question by informing the list that I live in Indiana.
> > Our humidity (in home) usually cycles from 65% in the summer to 30% in
the
> > winter.  Again these are averages of "in home" readings.
> >
> > I have been of the understanding that the heater bars used by
Dampp-chaser
> > are used to decrease humidity.  This is done by heating up the air
around the
> > heater bar.  Warm air holds more moisture than cold air.  So, moisture
is
> > drawn out of the piano and into the air... right?
> >
> > The question is: in the absence of a humidistat should the heater bar be
> > unpluged in the winter?
> >
> > The piano in question resides in a church.  Note:  The temperature
regularly
> > falls to 60 degrees during the week and back up to room temperature
during
> > services.   Also, I have not serviced this instrument and have no
humidity
> > readings from the site.
> >
> > I don't believe the heater bar should be used as a substitute for heat.
I
> > contend that the heater bar will compound the lower humidity (its'
intended
> > purpose).
> >
> > Without installing a humidistat or complete Dampp-chaser system, should
the
> > partial system be unplugged in drier seasons?
> >
> > Deeply pondering in Indiana
> >
> > Mike Bratcher
>