Dampp-Chaser Systems

[Don Rose]

Dear Randy:

Air currents affect humidity control systems on grand pianos very greatly. I have measured as
low as 4% relative humidity in a church type building in Weyburn Saskatchewan and as high as
84% in the same building.

DamppChaser systems work less well on grands. If a floor length "water proof" (I put this in
quotes, because water vapor has a smaller molecule <see Goretex fabric> and will penetrate most
materials) is not installed in Institutions the humdity increase p
rovided for by the dc will not be enough. Homes are a different matter because humidity levels
never go as low (they may go higher in summer though).

For the situation in Weyburn I have documented a 17 cent pitch rise overnight (I arrived found
the unit unplugged and plugged it in to return after other tunings). The instrument involved
is a rebuilt Steinway.

Happy New Year, Don Rose drose@sask.maple.net