Dampp Chaser, Humidity

[Ken Eschete]

tech@steinway.com wrote:
> 
> In our opinion, if the room can be succesfully kept within the range of 40
> to 55 % relative humidity, a Dampchaser is not necessary.
> 
> Steinway and Sons suggests the use of the Dampchaser when the location can
> not be controlled within these ranges.
> 
> Mike Mohr
> Steinway factory, NYC At 09:57 AM 11/9/97 -0500, you wrote:
> >Hi:
> >
> >I hope the subscribers of this list don't mind a question from somebody who
> >is not a tuner or technician.
> >
> >I own two Steinway grands: a model D less than a year old, and a model B
> >about two years old. My question relates to the necessity of using a Dampp
> >Chaser system.
> >
> >On the model D, the dealer installed a Dampp Chaser system and it has
> >always concerned me that the long rods are very hot -- you can't even touch
> >them for more than a few seconds.
> >
> >I brought this to the attention of the dealer's technician and he moved
> >them down a couple inches (thereby adding more holes to the piano
> >woodwork!).
> >
> >But still they remain very hot.
> >
> >On the other hand, the Dampp Chaser wants a drink every week! So it seems
> >that the system is fighting itself.
> >
> >The final straw is that I just bought a couple hand-held hygrometers (I got
> >two different ones to, hopefully, make sure they were in the ballpark with
> >their humidity readings). In the room with the model D, the humidity is
> >consistently between 40% and 50%, which sounds good.
> >
> >In a nutshell, is a Dampp chaser necessary in my scenario, and does it
> >appear to be malfunctioning since it is always very hot to the touch, yet
> >wants to be filled with water each week?
> >
> >Thanks very much for your comments.
> >
> >Frank Leister
> >Mechanicsburg, PA
> >
> >
> >
Dear Frank,

Scientific study carried out at the CAL Lab at the Smithsonian
Institution has measured the effects of temperature and relative
humidity on furniture.  There findings have established that a range of
RH between 40% and 60% should be maintained, and that it is most
important to keep the RH constant, even if it is slightly above or below
the recommended levels.

Personally, I follow the advise that it is better to control the room
RH, and that you should be more concerned about too little moisture,
than too much.  

I have not seen any independent scientific testing that proves the Damp
Chasers actually control the moisture content of the wood in pianos.
I invite anyone with evidence to present it.

Ken Eschete, RPT
Professional Associate - American Institute of Conservators  (AIC)
keschete@bellsouth.com