Piano and Humidity

The piano and humidity is a topic that is very confusing to many people. Humidity is one of the most significant factors relating to piano tuning stability Since moving to Penticton, I have discovered that pianos are probably more stable here than in most of the rest of the country. Where I came from in Eastern Ontario, a piano needed to be tuned at least twice a year, to be reasonably in tune most of the time. In summer the humidity was high and in the much colder winters, a good deal of heating was required which caused very low humidity inside the buildings. It is not the amount of humidity, within reason, that puts your piano out of tune but it is the change in humidity. When the moisture in the air increases or decreases, it is absorbed or released by the sound-board of the piano. The sound-board is usually made from Sitka Spruce which is quite a soft wood. Soft woods are more porous which causes a greater response to humidity. When the moisture level increases in wood it will swell. The swelling of the sound-board causes the slight crown to increase. The bridges ride on the crown and the strings cross over the bridges. This in turn causes greater tension on the strings which means the pitch has increased as well. In most of Canada the temperature drops significantly during the winter months which requires some type of heating. This heating in turn tends to dry out the air. The drying of the air will also reduce the moisture level in the sound-board of your piano and consequently, the pitch of the instrument will drop somewhat. Some pianos will respond more dramatically than others. To compensate for this drop in moisture it is beneficial to tune the piano after the heat has been on regularly for some time. Conversely, during the spring time the humidity will begin to rise again, in our homes because we are heating less. It is beneficial to tune the piano again at this time to compensate for the increase in moisture. There are some ways we can improve the relationship between your piano and humidity. We can attempt to reduce these large swings in humidity, in our homes. The more sealed our homes are the better they keep in the moist air, during winter time. Humidifiers can be added to forced air furnaces. A portable humidifier can be put in the room with the piano. In this case it is important that it work on a humidistat and the unit must not be allowed to run out of water. A very effective option is “Piano Life Saver System” produced by Dampp-Chaser Corporation. It is a humidity control system that we can put into the bottom of your piano in the case of an upright piano and underneath the sound-board of a grand piano. They are a two-component system. They have heater bars that gently heat the area to reduce humidity. The other part of the system has a humidifier with a small heater bar that releases humidity during the dry times of the year. If you have a situation where only humidity or only dryness is a problem the system can be set up for those situations. They work off a humidistat that attempts to keep the sound-board of the piano as close to 42 percent humidity as possible. They are very effective. They reduce the fluctuation of pitch in the piano dramatically. In Penticton, one of these units would probably reduce the required tunings to every year or two. If you are interested in learning more about these systems, please contact me at 250-488-9230 or email grant@piano4u.ca You may also use the

Return from Piano and Humidity to Home Page