DC

[Roger Wheelock]

Hello List,

At Dampp-Chaser one type of research is done at a constant relative humidity
of 70%.  Under these conditions a 50W dehumidifier in an upright piano will
complete the cycle with a complete cycle taking about 6 hours.  We cannot
maintain constant relative humidity in the 80-90% RH in our test rooms so we
haven't evaluated this type of situation.  Therefore, we welcome these types
of observations from the field.

One point that we would make is that when using an H2 Humidistat as a
control unit you cannot overdry the piano.  The failure rate on H2s is
negligible.  The last failure I can remember involved a lightning strike at
the piano owner's home, which fused a contact shut.

The sensor/switching mechanism we use is rugged and dependable.  Also, we
test each H2 for calibration and functionality prior to shipment.  This is
an uncommon practice in manufacturing today, but one that we choose to make
to ensure the quality of our product.

Please feel free to contact me directly if any of you have additional
questions.

Thanks,

Roger Wheelock, VP
Dampp-Chaser Corp.
roger@dampp-chaser.com


-----Original Message-----
From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
Of Farrell
Sent: Friday, January 11, 2002 9:21 AM
To: pianotech@ptg.org
Subject: Re: DC


Hi Phil. Hope you don't mind going public on this. I have a question for the
group at the end.

The potential need for more than 50W in a vertical is based on my own
experiments and observations. I had a 1098 that I installed one rod in. The
humidistat was cycling on and off around 50% RH. During periods of high
humidity (about 80% RH in the home), the DC did not turn off (I kept an
old-style electric clock with hands plugged into the humidistat also) and
the RH would not drop below about 60% to 65% RH (temp in room was 80 and
temp in piano was about 92F). Installed second rod and RH went down to 50%
and was maintained there. You just simply need enough wattage to make the
unit cycle off once in a while when the room is near the maximum RH commonly
encountered.

I think that one rod in a vertical in the typical air-conditioned Florida
home would be adequate. If they like to open windows and whatnot, two may be
needed to keep the RH in the piano down to targeted levels (or at least the
level which causes the humidistat to turn off at - I haven't observed even
one to make it down to 42% RH).

I wonder what the failure rate of the DC H2 Humidistat is. There are others,
like me, that advocate pumping up the wattage until the system turns off.
The only downfall to this practice is the potential for a humidistat to fail
and the unit stays on for a few years until the soundboard pops out. Anyone
have any info on this?

Terry Farrell

----- Original Message -----
From: "Phil Bondi" <tito@PhilBondi.com>
To: "Terry Farrell" <mfarrel2@tampabay.rr.com>
Sent: Friday, January 11, 2002 8:17 AM
Subject: DC


> Terry, I've seen 2 rods in the bottom myself..only in one piano
> (acrosonic)..I didn't see the added 'benefit' of the xtra rod..but that's
MY
> experience!
>
> Phil
>
>
>