CARE FOR YOUR PIANO!
Humidity fluctuations are the enemy of good pianos (and all wood instruments) everywhere. The single most important thing that you can do to ensure a long life for your piano, by far, is to maintain stability in the humidity level of the instrument. A piano stored in humid summer conditions and dry winter conditions will have its life span greatly shortened to the point where an instrument that might otherwise have outlived your grandchildren could be unable to hold its tune (and therefore nearly useless) in just ten or fifteen years.
In addition to being an essential task of piano ownership, controlling your piano’s humidity is also easy to do. All you need is a portable hygrometer and a humidifier. Don’t trust any built-in hygrometer, you need a portable model. You can purchase one for as little as $10. Choose a model without an external probe for measuring outside temperature. Place the hygrometer right on your piano or nearby because the humidity level of a home can vary a great deal from one room to another. Suitable humidity for a piano is 40-50%.
DAMP ISN’T GREAT BUT DRY IS WORSE
While extremely damp conditions may cause problems, it is winter dryness that can ruin a piano, fast. First, be certain that no heat sources focus directly on the instrument. Place the piano away from baseboard heaters or radiators. Forced air outlets are just as bad if they blow directly on the piano. Re-angle the vent, or if necessary, move the instrument. If this isn’t possible, close the vent and/or damper. If your house has old windows, also consider sun angle: sometimes, direct sunlight can also heat up and dry out a piano.
CONTROL YOUR PIANO’S CLIMATE
Fortunately, controlling the humidity of your piano is simple. In the summer, just running your air conditioner is probably enough to keep the humidity level below 60%. If not, get a room dehumidifier. In the winter, you will probably need a humidifier for the room. 40% is an acceptable humidity level; 35% is pushing it. If you have a central heating system with a working built-in humidifier, you may not need a room humidifier.
IS THIS WORTH THE EFFORT?
If your piano holds its tune reasonably well (i.e. is not horribly out of tune one year after its last tuning), the answer is definitely yes, regardless of how valuable the instrument might be.
FOR HIGHER-VALUE INSTRUMENTS
You can have a system (manufactured by Dampp Chaser) installed inside your piano which may aid in controlling the humidity automatically. These are available only through professional piano technicians, and require an up-front investment to buy and install (typically $450+). There is some debate over the practical benefit that the system provides. However, if you have a quality instrument and you find it impossible to adequately regulate the humidity level of the room in which it sits, this system may help preserve the tuning stability and life of your piano. Talk to your technician to weigh the pros and cons and see if this might be worthwhile for your particular situation.