Dampp Chaser, Humidity

[Howard S. Rosen]

----------
> From: Frank Leister <fLeister@mindspring.com>
> To: pianotech@ptg.org
> Subject: Dampp Chaser, Humidity
> Date: Sunday, November 09, 1997 9:57 AM
> 
 
> 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.

Hi Frank,

I must assume that the installation of the system was done correctly
whereby the the Humidistat (the rectangular box into which all the wires
are attached) is installed UPSIDE DOWN (very important). The writing on the
box should be upside down, that is, facing the soundboard. It should also
be installed on the wooden brace very close to the soundboard in order for
it to receive the proper feedback for it to cycle correctly.

If all is correctly installed, do not be concerned about the hot rods. That
is precisely their function. The humidistat is reading that the surrounding
air is above 42% and the system needs to bring it down. Hence, the dry heat
from the rods. When the air surrounding the soundboard reaches approx. 42%
it cuts off and then the humidistat cycles the humidifier on. These
functions are not fighting each other, but are cycling to maintain a
constant humidity level. 

 
> 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.

That may be the case right now, but not necessarily all year around. 
 
> 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?

In my opinion, a properly installed Dampp-Chaser system is good for your
pianos despite your negative impressions. The mere fact that it calls for
water each week is an indication that the humidity level swings enough to
warrant additional moisture from time to time.

I hope this is a help to you, and not confusing. I must stress the
importance of the location and position of the Humidistat. Perhaps you
should consider a consult from another Registered Piano Technician in your
area who can check this out for you. I invite you to e-mail me privately if
you need help with this. Good luck.

Sincerely,

Howard S. Rosen, RPT
Boynton Beach, Florida

hsrosen@emi.net