Air treatment

An instrument's environment

A piano manufacturer doesnt know where the instruments he delivers, are going to end up. Therefore, he cannot take the details of a new instruments circumstances into account. However, Clavis can do this, in consultation with you!

Moreover, when an instrument is moved, its surroundings and environment will change again. In short: pianos which contain wood and metal, cannot be adapted to their surroundings. The adaptations must be made in the instruments environment. The main factors piano owners need to consider, are temperature and relative humidity.

Temperature and relative humidity

A room's temperature is less important than one might think. Even though wood and metal tend to expand or shrink a little due to higher or lower temperatures, and though modern glues are still slightly sensitive to temperature, upright and grand pianos can generally handle these influences to a certain degree.

The temperature fluctuations arent the only danger; the fluctuations in humidity connected to these changes in temperature have a much more serious impact. The weather outside (atmospheric pressure, humidity and temperature) determines the amount of water vapour in the air. The air can be extremely dry, like in a freezer, or very damp or saturated, like on foggy or rainy days.

Relative humidity is the percentage or water vapour in the air in relation to the total saturation (100%) of the same amount of air at the same temperature. Warm air can contain more water vapour than cold air, which is why our summers are relatively more humid than our winters.

Although the materials in modern pianos can handle minor fluctuations in relative humidity, extreme drops or rises of humidity levels can be disastrous for your instrument (both inside and out)! The tensions in wood which dries (evaporates) too quickly, are of the kind no construction can withstand: the wood will warp and may even tear. When placed in an environment which is too humid, wood will expand and metals will oxidize, which can cause various parts to get jammed: keys will get stuck, pedals start to squeak, hinges and strings will get rusty.

It is important to monitor humidity, especially because upright and grand pianos contain different kinds of wood which each have their own specific moisture absorption properties.


The ideal humidity in our homes is between 40 and 60% as indicated on a hygrometer. A traditional hygrometer must be calibrated once a year, though. To do this, wrap the hygrometer in a soaking wet towel for half an hour. After leaving it in this towel for half an hour, if necessary, point the dial to 96%, which can usually be done with a small screw on the hygrometers bottom or back. Make sure you have a suitable screwdriver before you start calibration. Put the hygrometer up or put it somewhere in the room in which the instrument is placed.

If the hygrometers dial drops below 35-40%, you should start adding moisture to the room. There are a number of ways to do this. The OLD jars, filled with water, and old newspapers in the bottom of the piano are no longer used, because they tend to concentrate moisture in one place in the piano.


The hydroceel unit is an easy aid to limit extreme humidity fluctuations..

The unit is placed inside the piano and, if used properly, ensures regular moisture release when the air is very dry, and takes on excess moisture when the air is very humid.

Air humidifier

An even better and more effective way to correct relative humidity levels is using a humidifier, especially in case of a grand piano. A humidifiers main advantage is that it maintains the right level of humidity in the entire room, and by that, your entire instrument. Understandably, the rest of your furniture will benefit from this too. When you purchase a humidifier, make sure its capacity (in cubic meters) is high enough to humidify the entire room the instrument is placed in.

If your hygrometer indicates humidity levels above 70%, you should remove the hydroceel! If relative humidity levels rise above 80% for a longer period of time (this often happens in Autumn) you could consider having a heating element a thin bar, appr. 1 m long installed inside the piano, in the bottom. This installation must be carried out by an expert. Clavis's tuner is happy to take care of this for you.

Piano Life Saver by Dampp-Chaser

If you would like to ensure your instruments tuning is as stable as possible, we recommend the Piano Life Saver System (PLSS) by Dampp-Chaser. This device is installed inside your instrument and will constantly measure and regulate relative humidity levels; it will temporarily humidify the air locally by evaporating water, or dehumidify the air by activating its heating element. All this is done at quite specific humidity levels, ensuring a very stable tuning over a longer period of time. Your instrument will benefit from this kind of relative humidity stabilization in a number of ways. For instance, its fine-tuning will remain more stable, it will prevent mildew formation and prevent the soundboard and pinblock from getting damaged. If you are a professional pianist, or if your instrument goes out of tune quickly, we would certainly recommend the Piano Life Saver System.

Dampp-Chaser's Piano Life Saver System (PLSS) allows you to minimize relative humidity fluctuations. The device consists of different parts, which are installed inside or underneath your instrument.

1. A humidistat, measuring relative humidity levels.

2. A dehumidifier which is activated when relative humidity levels are too high

3. A humidifier which is activated when relative humidity levels are too low

4. A 3-light panel allowing you to read off the device's state

5. A watering tube, making it easy to refill the humidifier

The humidistat directs the system and will maintain relative humidity levels at 45%, which, among other things, will ensure an excellent tuning stability. Maintenance is simple. Every 2 to 4 weeks, you need to refill the humidifier with a special watering can via the watering tube. One of the lights on the system's panel will indicate when it is time to do this.

The humidifier requires maintenance carried out by an expert once per year. When in use 24 hours a day, the devices power use is 996 W. The system is completely silent.

Prices for a built-in Piano Life Saver System start at € 685,00 including installation, depending on the type of piano (upright or grand) and in case of a grand piano, the length of its case. If you buy or rent an instrument from Clavis and decide to have the system installed prior to delivery, we will offer you a 15% discount on the PLSS.

For more extensive information about the Piano Life Saver System, please click here.