how much humidity control?

[alpaca]

I've read that optimum humidity for pianos is 40-50%.  My hygrometer shows daily room fluctuations in humidity between 43-53% (in the summer).  Is this good enough, or should I be concerned about the 10% daily fluctuations?  I don't know what the winter fluctuations will be.

thanks

[mic2005]

The ideal RH is between 42-65 and fluctuations of no more than 5%. In your case the fluctuation looks high. I would suggest installing a damp-chaser system to minimize the fluctuation.  During winter RH could drop as low as 20s depending to regions. The damp-chaser system will maintain constants RH.
Regards.

[mfortin]

Hello,
I have been told by my piano technician that damp chaser are very good for upright piano but not so much for grand...

[mic2005]

I am sure if the damp-chaser is install properly it will benefit both upright and grand.

Regards,

[Axtremus]

I've read that optimum humidity for pianos is 40-50%.  My hygrometer shows daily room fluctuations in humidity between 43-53% (in the summer).  Is this good enough, or should I be concerned about the 10% daily fluctuations?  I don't know what the winter fluctuations will be.

You're doing just fine. Day to day fluctuation is inconsequential because the wood simply do not absorb or shed moisture that fast. It's the deep, seasonal swing that you want to watch out for. If you're seeing ~70% RH for three months in the summer and then ~30% RH for three months in the winter, that's when you go buy humidifiers for the winter months.

My idea of an "ideal RH" is one in which my family and I can live and breath comfortably. I see no point in maintaining an RH level good for the piano but bad for the piano owner (well, unless you're operating a piano museum).