Damp Chaser in old upright

[Warren Fisher]

Daniel,

Do live in a dry area?  You said you got a humidifier for your house.  If your
normal humidity is less than 42% most of the time, you don't need a
damppchaser..  The humidity in my area is running around 85% right now and goes
down to 35% in winter.  I do.

How does it work?  Heated air holds more moisture than the regular air.  If you
heat the air inside an upright for instance, it will remove moisture from the
soundboard as it rises past it. If you remove an amount of moisture from the
inside of the soundboard equal to what the soundboard is absorbing on the back
of the piano,  then the moisture level of the soundboard will be in balance and
board will not swell and cause the pitch of the strings to go sharp.

Does that answer your question?

Warren

Daniel Lindholm wrote:

> Thanks for that post!
>
> I've always been somewhat curious about how it works in a piano. I thought
> it might work pretty good in a piano since its inside the cabinet and not in
> the open. Still, the outside wouldnt get the same humidity as the inside, I
> was thinking that at least the soundboard would be okay. Could you please
> tell us something about the soundboard? How did the strings look like?
>
> I've been told NOT to get a dampchaser for my grand piano. Most techs just
> say 'that will ruin it', and when you think about it. How good could it be?
> The damp will get concentrated around smaller parts of the piano and the
> same goes for the heatingdevice. I bought a humidifier for the room and (I
> guess many of you will say that I'm all wrong about this dampchaser and that
> its really really good, but...) noone could ever say that its better to use
> a dampchaser than to control the whole room that the piano is in
> (humidifier-dehumidifier and something to circulate the air).
>
> To summorize my post so I dont have to get 100 angry replies saying that I'm
> all wrong etc:
> I'm a bit skeptic to this dampchasersystem, but I dont say it doesnt work.
> I'm pretty sure that it will have some effects (but I'm not quite sure if
> they are good or bad). I wouldnt want a heatsource or a humidifier that
> close to the wood in my piano. I think its pretty obvious that the
> heat/humidity will be concentrated to some areas around the actual device.

No the heat causes the air to rise, which draws in cool air from the outside to
flow to the rod to be heated.  To make it work right you have to have the
humidistat switch to turn the rod off when it gets down to 42% so it doesn't get
too dry.

>
> That I know for certain is that the best thing is to get a system to control
> the entire room.
>
> Its an interesting topic. All salesmen recommends them and are selling them
> hard, but I havent heard a tech that recommends them. I hope to see some
> more post regarding this topic, with people telling about their experiences
> with dampchasersystem (both in uprights and in grands). Taking up an
> instrument that has had a system like that installed for 25 years is a
> really good example. If anyone else have experience with instruments with
> system installed over a longer period, please do reply!
>
> I'm really curious although I have already made the choice for my piano.
>

--
Warren Fisher RPT                   Beginners & Lurkers
fish@Communique.net                 Basic Pianotech discussed
1422 Briarwood Dr.                  Ask any question.
Slidell, LA 70458-3102              fish@gs.verio.net