Humidistat Performance

[Farrell]

John:
My understanding is that for the humidistat to function as designed, it
would switch the dehumidifier on @ 46% RH and switch it off when RH is 38%
(or so). If a humidifier was installed, it would switch on @ 38% RH and
switch off @ 46% RH. Obviously, if a humidifier is not installed, all would
be off for the period it takes for RH to increase from 38% to 46% (or there
abouts). But for all my tests to consistently be hovering around 60% - I
just don't understand.

My reasoning for this being important to me is this: In Florida, RH in a
home drops to a low of approximately 35% during dry winter months (and
therefore, I do not see the need for humidification). If the dehumidifier
kept the soundboard environment to a maximum RH of around 42% (as
advertised), my overall RH range would be about 35% to 45%. Considering my
observations of my humidistat's performance, the RH range for the soundboard
is about 35% to 62% - not nearly as good as it presumably could be.

Don:
I have three hygrometers. The one sold by DC, another similar one, and one
that may be a bit better. All three are within 1 or 2 percent of each other.
I'm thinking of forking over the dough for a real good one. Bob Mair @ DC
recommended a couple of units that are more accurate. They run in the $200
to $350 range, depending on features.

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

----- Original Message -----
From: "John M. Formsma" <jformsma@dixie-net.com>
To: <pianotech@ptg.org>
Sent: Wednesday, March 08, 2000 10:44 AM
Subject: RE: Humidistat Performance


> Terry,
>
> Don't they mention this in the literature? I think I read that this is by
> design. Something about creating an enviroment that is not suddenly
changing
> all the time.
>
> John Formsma
> Blue Mountain, MS
>
>
> -----Original Message-----
> From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
> Of Farrell
> Sent: Wednesday, March 08, 2000 9:17 AM
> To: pianotech@ptg.org
> Subject: Humidistat Performance
>
>
> Hello List:
>
> I have been monitoring performance of DC humidistats in my shop. I am
> finding that the relative humidity (RH) on-off points for the humidisats
> (dehumidifier outlet) are in the 55% to 65% range, rather than somewhere
> centered around 42%. I have done my field testing using several different
> humidistats. Has anyone else monitored the performance of humidistats? I
am
> having trouble understanding why my observations would vary so much from
> what I understand to be advertised.
>
> Terry Farrell
> Piano Tuning & Service
> Tampa, Florida
> mfarrel2@tampabay.rr.com
>
>