I have a Weber player piano, that currently is sent away  for repinning
and  restringing, because of the too low humidity the previous owners
exposed it to.  I plan to treat it much more carefully, by adding
moisture, especially in the wintertime, when the air is dry here where
I live in Oslo.

The problem is what unit I should use for this.  The most advanced
ones, where you can regulate the %-tage of humidity are really
expencive, and the cheaper ones may very well fog the windows, when
accidentally set too high.

Also the room where the piano lives is not very large (appr. 20 sq
metres), so a moisturizer, will probably be difficult to set to a low
enough level.

The moisture level jumps up and down between 50 and 80% because of poor
ventilation, and changing conditions when someone hangs up laundry, or
the sun heats up at the opposite of the room.

A piano tuner once suggested that it would be OK to put one or two jars
in the bottom of the piano, and make sure they are filled with water
every week or every 14th day.

Do anyone have suggestions to solve this problem, or comments to that
advice I got.

Sincerely Thomas Henden, Oslo, Norway.