Relative Humidity Changes and Old Pianos, was: CA and Accelerator and Happy Clients!

[Andrew & Rebeca Anderson]

Damppchaser offers a "wet" hygrometer, ~55%RH if memory serves me 
correctly.  That should be good enough for coastal climates.  More than 
that is detrimental IMHO.

Andrew
At 04:42 PM 5/22/2005, you wrote:
>AF wrote:
>
>Most of the pianos in this country are over 80 years old
>
>Really? Says who? I know some days it seems that way, but I don't think 
>that is true at all.
>
>and have acclimatized to a RH of 65%.
>
>Really? Says who? Where do you get such data from? Most environments do 
>not have fluctuating relative humidity levels?
>
>Ideally, the installation of a climate control system should maintain that 
>65% to avoid any damage.
>
>Why would a slightly drier environment cause any damage? All the wood in 
>that piano grew for 100 to several hundred years at something like 50% MC 
>(what is the moisture content of green wood?). Somebody dried it out after 
>they cut the darn thing down - didn't do much damage then - why would a 
>small change in MC damage it now? IMHO, hesitating to create a stable 42% 
>RH (or there abouts) environment for an old piano is nonsense.
>
>The Dampp Chaser literature that I have does not state whether you can set 
>it to maintain existing conditions, and am therefore very reluctant to 
>recommend the system for old instruments; new ones, fine.
>
>New piano, old piano, same difference, IMHO.
>
>Terry Farrell