Tom DeFerrari Piano Tuning and Servicing: Piano Placement and Humidity Control

Tom DeFerrari Piano Tuning and Servicing

.Piano Placement and Humidity Control

.Humidity

Where a piano is placed is very important for both its tuning stability and its longevity.

The best place for a piano is where humidity remains fairly constant, ideally in the 40% to 50% range. The temperature of the room isn't as important, except as far as it affects the humidity. However, keeping a piano away form direct heat, especially forced air, is very important.

Why stable humidity is important

There are 3 reasons why it is important to keep the humidity constant, and in the 40-50% range, and why it is important to keep a piano away from direct heat.

Tuning Stability One of the main reasons a piano goes out of tune is because the soundboard expands or swells when humid, and contracts or flattens out when dry. When it expands, it presses against the strings, putting them under more tension, and the notes become sharp, or higher in pitch. When the soundboard contracts, the tension on the strings loosen, and the notes become flat, or lower in pitch. However, they don't all become sharp or flat equally, so the piano goes out of tune. See Why a piano goes out of tune for more information.

Longevity The three major structural parts of the piano (the soundboard, the bridges and the pinblock), are made of wood and are susceptible to drying and cracking. This is likely to happen prematurely if the humidity is too low, but it is even more likely if the humidity swings from being very humid in the summer to very dry in the winter. In addition, if the piano is near direct heat, these cracks can develop even if the overall humidity is kept constant. Cracks in the soundboard and bridges can cause annoying rattles and buzzes that can be difficult and expensive to repair. If the pinblock becomes dried out, the tuning pins will slip and it will no longer hold a tune, even if the humidity is kept constant afterwards. Replacing the pinblock is a major rebuilding job, which requires restringing the piano, and is fairly expensive.

Sticking and clicking notes The keys and the internal moving parts of the piano are called the action. These parts are made of wood and felt, and are held in place with various screws and glue joints. If the action becomes too humid, the wood swells and notes can become sluggish, or not work at all. If the action becomes too dry, screws and glue joints can become loose, causing action noises, and failing notes. In addition, the action parts' relationship to one another, called regulation, is affected by changes in humidity, and can change the touch or feel of the piano. These problems are kept to a minimum if the humidity inside the piano is kept constant and moderate.

.How to determine if the humidity in a room is ideal for a piano.

The best way to determine if the humidity in a room is ideal for a piano is to monitor it with a digital thermometer/hygrometer, which is just an electronic thermometer that also displays relative humidity. They are available online, at departments stores, and at Radio Shack, like the one shown below (chosen only because the picture was so clear).

The digital thermometer/hygrometer shown above is from Radio Shack and costs $20. The 23% displayed at the bottom of the unit is the humidity measurement, and this is what should be monitored.

.Methods of keeping the humidity stable

Control room humidity The best way to keep a piano's humidity stable is to keep the humidity in the room it is in stable. This can be done with a humidifier during the winter, and with a dehumidifier during the summer, using a digital hygrometer to determine when either is needed. When the hygrometer shows that the humidity is below 40%, the humidifier should be turned on, if it shows above 50%, the dehumidifier should be turned on (newer models of both humidifiers and dehumidifier can often be set at a given humidity level, making this much easier, but I recommend monitoring the humidity with a digital hygrometer to make sure). This may require a bit more effort than the system mentioned next, but is really the best method, in my opinion. In addition, if the room is too dry for a piano, it is probably too dry for people.

Piano humidity control system This is a system that is installed inside a piano by a piano technician. I carry and install these systems, and I have more information about them here. These systems can be effective, and are easier to operate than room humidifiers/dehumidifiers. but they are a more expensive solution, they don't humidify the rest of the room, and, especially in a grand piano, are not as effective as keeping the humidity inside the piano constant.

Partial solutions I hesitate to say this, but frankly, for some people, their piano isn't the only concern in their life, and dealing with either solution above may seem to be too much of an expense or bother. If keeping the room humidity level constant seems too difficult, and a piano humidity system is not in the budget, it is very important to at least try to keep the piano from getting too dry. Excess dryness is much worse for the longevity of a piano than excess humidity. Fortunately, humidifying is much easier than dehumidifying, and humidifiers are fairly inexpensive, so I would strongly recommend at least humidifying the room if it is getting too dry. In addition, the next section on mitigating bad placement is also important.

.Mitigating bad placement

The worst thing for a piano is for it to be directly on top of or beside a hot air register. Almost as bad is to place a vertical piano (a full upright, console, or spinet) against a wall that has a baseboard heater at the bottom.

However, sometimes, a house is set up so that there is no choice but to put a piano near a heat source. There are some things can be done to mitigate this, keeping in mind that it is much better, if at all possible, to find a better place for the piano

If the piano is near a hot air register, airflow can be redirected away from the piano. There are inexpensive commercial products that do this, which are typically plastic caps that go over a heat vent with an opening that changes the airflow to a different direction. Alternate ways can also be found, and for someone handy with woodworking, it isn't too difficult to construct something along the same lines out of wood, which might be more attractive. Sometimes the solution may be as simple as putting a piece of furniture between the heat source and the piano that will deflect the air flow away from the piano.

If an upright piano is up against a wall with baseboard heat, putting a sheet of insulation board between the wall and the back of the piano will deflect the rising heat away from the piano and also tend to insulate it from the heat of the heater. This sheet of insulation can be cut this down so it is a bit smaller than the width and height of the piano so that it isn't as noticeable.

.Placing the piano in direct sunlight.

I mention this separately, because it is important more for the cabinet of a piano than the internal parts. About the only way that direct sunlight will hurt a piano internally would be if the sun were shining right onto the soundboard of a grand piano whose lid is always kept open. This can cause it to dry it out and create the longevity and tuning stability problems mentioned above.

Direct sunlight can, however, damage the appearance of a piano. It can cause the finish to crackle prematurely, or even bleach the cabinet, so that the piano has a lighter shade where the sunlight hits than in other areas. The solution is to place the piano away from direct sunlight and keep the shades drawn at the appropriate times of the day.

.Placing the piano against an outside wall.

Piano tuners and technicians sometimes warn against this, but it was probably a more appropriate warning years ago when houses were poorly insulated and sealed. If there isn't a noticeable draft against an outside wall, and it doesn't get noticeably cold, placement against an outside wall is usually not a problem.