What temperature and humidity is best for a piano?
65–72 degrees is a good temperature range, but a constant humidity level of near 45% is more important. In our climate, the humidity level fluctuates like a roller coaster, causing the air to act like a wet/dry sponge. Unfortunately, the soundboard, pinblock, and thousands of action parts change with it. This promotes problems like tuning instability, warpage, cracked soundboards, loose glue joints, squeaks, rattles, loose tuning pins, sluggish keys and string rust.
Most homes and buildings lack the ability to keep air moisture constant and are therefore too humid in the summer (over 70%) and bone dry in the winter (as low as 10%). For a piano, this kind of change is extreme. Running a dehumidifier in the summer and a humidifier in the winter will certainly help. This solution, however is still less than ideal since, for example, trying to maintain a 45% humidity level in the winter can cause major condensation problems and damage your home.
One solution, especially for a piano that goes drastically out of tune due to seasonal changes, is to have a Dampp-Chaser humidity control system installed inside your piano. This completely silent, maintenance-free system keeps your piano at a constant 42% relative humidity year-round. This product has proven track record over many years. It is endorsed by all major piano manufacturers. When installed properly, the system will pay for itself by protecting your piano and in many cases, allowing a less frequent tuning schedule.