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Comments interspersed below:
Terry Farrell
----- Original Message -----=20
From: Sarah Fox=20
To: Pianotech=20
Sent: Wednesday, January 14, 2004 9:19 PM
Subject: Re: Where did the RH Go
Hi Terry,
I understand DC's contacts are rated at 15A (about 1600+ W), so 35W is =
hardly a significant load. However, I'd be concerned about a running a =
dehumidifier straight off of such a humidistat. I bet the average =
electrical load for a dehumidifier is 500W running, which would =
correspond to about 1500W at startup -- perhaps enough to fry the =
contacts. Dunno.... Check the ratings!
The rating on my old dehumidifier was 600 watts. I don't know much =
about electricity. The startup thing may well be of concern. Mine worked =
fine for about a year, but perhaps I was lucky. Maybe some other =
humidistat would work better.
The prospect of running a room humidifier from an under-piano =
humidistat is appealing. I would be cautious not to run it opposite the =
dehumidifier bars, though. A situation would arise in which both the =
temperature and humidity would rise in an inverse-compensatory fashion. =
If I were to install a DC-type system on a piano, I would put the =
humidistat under the piano. If I were to run a room dehumidifier or room =
humidifier off some type of humidistat, the humidistat would be placed =
somewhere in the room where it would get a good representative flow of =
room air to it - it would NOT be located in/under a piano!
At the same time, the room would get quite nice and steamy. ;-) I =
would think it best to switch seasonally between humidification and =
dehumidification modes, disabling one side or the other. Of course I =
think running heater bars opposite buckets in a full DC installation is =
a bit silly as well. If the piano owner is capable of such technical =
matters, it would be better to have him/her buy a cheap hygrometer and =
switch the system back and forth (or plug/unplug) according to =
humidification/dehumidification needs.
In the end, I think the most trouble-free, no-brains system is the one =
I have. The heater system under the piano takes care of the =
microcontrol with its own humidistat. I leave it on constantly, =
throughout the year. Then as ambient humidity drops below 45%, I run a =
humidifier on its own humidistat (not under the piano), so as to =
maintain the ambient humidity at 45% (the upper end of the under-piano =
system's operating cycle), or as high a humidity as won't create a =
problem with regard to window/wall condensation (currently 38 or 39%). =
DC buckets may be an attractive option in extreme climates where the =
outside temperature gets so brutally low that the interior RH can't be =
maintained at a high enough level without condensation. The climate =
here in Ohio may be borderline, as 38 or 39% seems to be my limit right =
now.
I think you are likely right. Install an appropriate DC system on the =
piano, and cut down on the room RH extremes with room =
humidification/dehumidification. I would be curious to witness the =
effectiveness of a complete DC system installation with back covers and =
the whole shebang in an extreme environment.
I haven't tried this yet, but in the spring I will be running a =
dehumidifier downstairs on a timer (night-time running only, for =
considerations of noise), so as to drag the household humidity a bit =
lower. I'm convinced the materials of the house hold considerable =
moisture and therefore serve as an intermediate-term humidity buffer. =
This would explain why it took so long for me to dehumidify a wet cargo =
trailer -- and why the RH would shoot up within minutes of my shutting =
off the dehumidifier until I finally got all the excess moisture out of =
it. The entire process took a few days. It was utterly amazing how =
much water that wood cold hold!
Absolutely! Once in a while, even when it is high RH outside, like =
when I might be spraying lacquer in my shop, I will open windows and =
turn on my exhaust fan. The RH will shoot up to near whatever it is =
outside - let's say 80%. I haven't timed it, but within an hour or two =
after closing the windows, the shop RH will be right back down to 45% or =
so - very quickly. I don't know how much wood I have in my shop, but I'm =
quite sure at least several thousand. At 8% MC, those 3,000 lbs. of wood =
would contain 240 lbs. of water, or about 30 gallons. About every 7% or =
8% change in shop RH, will, over enough time, cause about a 1% change in =
EMC in the wood, or will add or remove 24 lbs. of water, or about 3 =
gallons of water.
Now, it's too early in the morning for me to calculate the volume of =
water in my 7,000 cubic-foot shop. But if anyone wants to, calculate the =
volume of water in the shop at let's say 45% RH (70 degrees), and then =
calculate the change in water volume in the shop air with a rise to 75% =
RH (or whatever). Then you can easily see how easy it would be for the =
wood to absorb/desorb this volume of water. I suspect the numbers would =
make it quite clear that the wood in the shop (or the carpet and =
furniture and walls, etc. in a home) will serve as a pretty effective =
buffer.
And I guess one would want to consider the rate at which the wood will =
absorb/desorb water........... (yawn.....)
Terry Farrell
Peace,
Sarah
----- Original Message -----=20
From: Farrell=20
To: Pianotech=20
Sent: Wednesday, January 14, 2004 8:04 PM
Subject: Re: Where did the RH Go
I have a Sears basement-style humidifier in my shop with and =
"electronic" humidistat. It is quite accurate - I'm really pleased with =
it. The older dehumidifier I had before this one had a garbage =
humidistat - that is why is ran it off the DC H2 unit. I your humidifier =
has a functional humidistat, then that is great. The H2 unit may be =
something to consider for someone that has a humidifier or dehumidifier =
that is not equipped with a decent humidistat - BUT, no reason to place =
the H2 under the piano! Put it out in the room where it can do its job =
in keeping the room at the desired RH level.
Terry Farrell
----- Original Message -----=20
From: Sarah Fox=20
To: Pianotech=20
Sent: Wednesday, January 14, 2004 7:37 PM
Subject: Re: Where did the RH Go
Hi Terry,
I use a Kenmore model 42.14125 unit, which has its own internal =
humidistat (so current draw is not a limitation). The total draw of the =
system is quite low, at 37W (0.33A), so it could be plugged into a DC =
humidistat -- or the GE humidistat I use. The default humidity setpoint =
is something like 60%RH, so it would cycle on and off satisfactorily =
with the under-piano humidistat. There are much cheaper ultrasonic =
units that don't have humidistats. These would be even better suited =
for being switched on and off by the under-piano humidistat -- at the =
end of a very long extension cord, of course! :-)
Peace,
Sarah
----- Original Message -----=20
From: Farrell=20
To: Pianotech=20
Sent: Wednesday, January 14, 2004 7:01 PM
Subject: Re: Where did the RH Go
What type of room humidifier are you using? How many watts does =
it use? I think the H2 humidistats are rated up to 600 watts. I have ran =
a Sears basement-type dehumidifier off a humidistat in the past. That =
would solve your troubles for when you travel.
Terry Farrell
----- Original Message -----=20
From: Andrew & Rebeca Anderson=20
To: Pianotech=20
Sent: Wednesday, January 14, 2004 10:34 AM
Subject: Re: Where did the RH Go
My wife and I regulate humidity (in winter) through the whole =
house with two humidifiers and a gauge on a bookshelf by the piano. =
This requires some attentiveness, and is affected by outdoor weather. =
The problem comes when we travel. We were away over the holidays for =
two weeks and when we returned the humidity was in the high single =
digits. The piano sounded horrible. We got humidity up in a few days =
and in two weeks I retuned. We have developed a rather low-tolerance =
for out-of-tune. =20
The issue is practicality. Most customers will not go through =
the trouble of monitering RH and refilling, turning on/off their =
humidifiers on a daily basis. Once a piano is up to humidity, the DC =
will usually last a week often more, it only has a small environment to =
keep-up. The humidity migrates through the wood, even in a grand piano =
pin torque is affected (closed lids do help in extreme environments). =
Buying a room humidifier that has a remote-control humidistat will cost =
more than a DC system, although it would benefit all the wooden =
furniture too. I have discussed this with clients and some have chosen =
to get a cheap hardware-store hygrometer and start running a room =
humidifier. They last about halfway to the next tuning and then want a =
DC system or believe they can tolerate the effects on the piano.
Andrew Anderson
Las Cruces, NM
At 06:40 AM 1/13/2004 -0500, you wrote:
I don't think anyone is questioning the effects of RH =
changes on the tuning of a piano.
=20
I'm with Sarah and feel that proper full environment =
humidity control is the best way to go - better than a full DC =
installation.
=20
I think where the arguement comes in is the fact that =
probably 99% of full environment humidity control systems are improperly =
designed, poorly functioning, turned off and windows opened up, turned =
off over the holidays and summer, etc., etc.=20
=20
But this does not change the fact that if one installs a =
proper full environment humidity control system that holds the RH =
constant within a few percent, it will be more effective than a full DC.
=20
And don't forget that even if you hard-wire the DC system =
into the wall, who is ever going to notice that the circuit breaker =
tripped 15 months ago and the piano hasn't had any humidity control =
since that time?
=20
In my shop I have a Sears basement-type dehumidifier. It =
keeps the shop right at 45% RH (within a percent or two). I never =
varies. How in the world is a DC unit on a piano in my shop going to =
work better, or do anything at all besides vapor, dry, vapor, dry, =
vapor, dry, etc., etc.?
=20
So I guess the bottom line is that if one is willing to set =
up a proper full environment humidity control system that holds the RH =
constant within a few percent, that is the best way to go. From a =
practical standpoint, knowing that 90-some% of full environment humidity =
control systems are not going to be real effective, the full DC-type =
system is the way to go (they DO work quite well). And as someone =
pointed out, from a practical standpoint a full DC-type system in a =
piano which is in an environment modified by a full environment humidity =
control systems is the best around.=20
=20
Flame Suite Tighly Zipped,
=20
Terry Farrell
=20
----- Original Message -----=20
From: "DIANE HOFSTETTER" <dianepianotuner@msn.com>
To: <pianotech@ptg.org>
Sent: Tuesday, January 13, 2004 2:51 AM
Subject: Re: Where did the RH Go
> Sarah,
>=20
> For fourteen years now my partner and I have been =
measuring and graphing the=20
> tuning on every piano immediately before we tune it. We =
also record the=20
> relative humidity and temperature most of the time, =
whether it has a=20
> Damppchaser installation or not, and if it is functioning =
correctly.
>=20
> Then when we next tune the piano and record all the data =
again, we have a=20
> way of understanding how to service the piano to make the =
tuning as stable=20
> as possible.
>=20
> Over the years I have had fun with a variety of =
experiments. One day I=20
> arrived to tune a piano in a room that is routinely kept =
unheated with no=20
> climate control in the piano. The maintenance people had =
just turned on the=20
> heat before I arrived and a stream of warm area was =
shooting out of the=20
> register about ten feet away.
>=20
> I was dismayed; the heat should have been turned on hours =
before. I knew=20
> the tuning could not be reliable. I went ahead and =
graphed the tuning. As=20
> soon as I finished that graph, I remeasured the tuning and =
graphed it again.=20
> Then I remeasured and regraphed, and then once again. I =
ended up with a=20
> graph showing four distinctly separate lines of the tuning =
as it changed=20
> with the relative humidity and temperature for each line =
carefully recorded.
>=20
> There is no question in my mind that changes in relative =
humidity affect the=20
> tuning dramatically and that a Damppchaser system does an =
excellent job of=20
> helping control that. I have numerous graphs to show it =
does.
>=20
> Diane
>=20
>=20
>=20
>=20
>=20
> Diane Hofstetter
>=20
>=20
>=20
>=20
>=20
> >From: "Sarah Fox" <sarah@gendernet.org>
> >Reply-To: Pianotech <pianotech@ptg.org>
> >To: "Pianotech" <pianotech@ptg.org>
> >Subject: Re: Where did the RH Go
> >Date: Mon, 12 Jan 2004 21:48:30 -0500
> >
> >Hi Don,
> >
> > > I did not say your system didn't work. What I said was =
a DC system would
> > > work even better.
> >
> >Perhaps. Perhaps not. I don't mean to be argumentative =
on this point. =20
> >I'm
> >really asking a question here: Have you (or has anyone =
else) done
> >measurements with a good, accurate hygrometer on a =
complete DC grand
> >installation, during dry ambient conditions, showing that =
humidity is=20
> >indeed
> >evenly distributed all over the soundboard, both under =
and on top, and in
> >the action cavity? Also, have the same measurements been =
done inside the
> >piano with a closed lid and inside the action cavity =
during predominantly
> >dehumidifying periods? In other words, are DC's claims =
fully=20
> >substantiated,
> >as determined empirically with a hygrometer? I've heard =
lots of claims
> >regarding stability of pitch. That's all well and good, =
of course.
> >However, how well does the DC system regulate humidity =
(in contrast to
> >pitch)?
> >
> > > I do recommend room type humdifiers as well--but only =
to "assist" a DC
> > > unit. If it is a choice of one or the other the DC =
provides much better
> > > year round control than is generally possible with a =
room type. There=20
> >are
> > > exceptions, but they are very rare.
> >
> >This sounds like a reasonable approach.
> >
> > > Do you have measurements for the summer time? Where I =
am I have=20
> >documented
> > > as low as 4% and as high as 84%.
> >
> >Without humidification, humidity levels inside my house =
vary from 27% in=20
> >the
> >winter to 67% in the late fall. I have forced heat and =
refrigerated A/C,
> >BTW. I suspect humidity levels are far different in =
other parts of the
> >state. I'm in Central Ohio. In the lake areas, humidity =
is undoubtedly
> >much higher during moderate weather. Also, I have no =
idea what humidity
> >levels occur in other people's homes here in Columbus. =
(I don't service
> >their pianos. <grin>)
> >
> > > I would love to have a controller for a DC type system =
that had much
> > > narrower limits. I know, for example, that rare bird =
hatcheries have=20
> >units
> > > that are calibrated to 1/10 of one percent humidity =
that power an
> > > "electronic" fan (read no blades--some sort of =
vibrating plate) combined
> > > with an ultrasonic humidifer. I'd love to get my =
pinkies on one!
> >
> >Well, I can't boast 0.1% limits with my system (WOW!!), =
but I do quite a=20
> >bit
> >better than the specs DC boasts. I did a 100% =
non-DC-brand installation on
> >my concert grand, using a GE humidistat that cycles the =
system adjustably
> >between 40 - 44% (or occasionally as widely as 39 - 45%) =
when the ambient=20
> >RH
> >is in the upper 40's. The installation is fairly recent, =
so I haven't yet
> >been able to observe its behavior at higher humidity =
levels. I'll give you
> >an update in the spring if you're interested.
> >
> >Peace,
> >Sarah
> >
> >
> >
> >
> >_______________________________________________
> >pianotech list info: =
https://www.moypiano.com/resources/#archives
>=20
> =
_________________________________________________________________
> Scope out the new MSN Plus Internet Software - optimizes =
dial-up to the max!=20
> =
http://join.msn.com/?pgmarket=3Den-us&page=3Dbyoa/plus&ST=3D1
>=20
> _______________________________________________
> pianotech list info: =
https://www.moypiano.com/resources/#archives
>
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