The environment in which the instrument lives.

A piano manufacturer does not know ahead of time in what kind of home a supplied instrument is going to reside. The manufacturer can therefore not take into account in detail in which circumstances the instrument will dwell. However, in consultation with you, Guus van den Braak is able to do so! When moving home, the instrument will again be placed in a different climatic environment. In a nutshell, a piano or grand piano, that contains wood and metal, cannot adapt outside its surrounding. The adaptation will need to take place in its own environment. The foremost factor a piano owner needs to be concerned with is controlling the relative humidity.

Temperature and relative humidity (RH).

          Wood and metal do have an inclination to expand and contract a little with higher, respectively lower temperatures. The types of glue used these days are to some extent still sensitive to temperature changes, but pianos and grand pianos are able to cope with those temperature changes within certain tolerances. The danger lies not just only with changes in temperature but much more with the coherent humidity in the air. The outside weather (Air pressure, humidity and temperature) determines the amount of moisture in the air. Air does hold an absolute or actual amount of moisture. These amounts vary depending on the temperature and pressure of the air at the time. As the temperature increases, the air expands and is then able to hold more moisture. Given that the air has an absolute amount of moisture in it, and that air is now warmer, due to its increased ability to hold more moisture, the air's RH is now lower because relative to the absolute amount of moisture it can now hold more. This results in a transfer of moisture from such porous materials as our skin and wood or the ground. This transfer of moisture will continue until the levels of moisture equalise. In reverse, as the air cools, its ability to hold that moisture decreases, increasing the RH and trying to unload the moisture it has into the porous materials in the environment. If those materials can no longer take on more moisture, condensation will occur in some form or other.
          Climates with extreme high and low humidity variations in their wet/dry or summer/winter seasons (Darwin, Brisbane, Perth, Adelaide) are extremely damaging to pianos and can be disastrous or fatal to your instrument, internal and external! The tensions in woods drying too rapidly, are of such a nature that no structure is able to stand up against it. Wood will become warped and would crack. Wood will swell in a too humid environment and metals will oxidise, by which all sorts of parts can get jammed: sticking keys, noisy pedals, hinges and strings become rusted. Because different kinds of woods are incorporated, each with their own specific properties and ability to absorb moisture at a different rate, controlling the relative humidity is a very important matter.

          The ideal RH in our home is 42%. Read on and find out why. EMC (Equilibrium Moisture Content) is a measure of the amount of moisture present in wood. This is directly affected by the RH of the air around the wood. As mentioned earlier, when RH increases, the air is trying to unload its moisture into anything that will soak it up and wood is ideal. Even with a coating of varnish or other finishes, moisture in the air will still permeate into the cell structure of wood. The only way to prevent excessive moisture content, or the lack thereof, is to control the RH around the wood. Hence the need to use a Humidity Control System.

The ideal EMC for wood within a piano is determined by most manufacturers to be 8%.
To maintain an 8% EMC, an RH of 42% is required.
The safest range of RH for wood is between 35% and 55%. RH swings within this range reduce the risk of destruction of the cell structure. If RH swings are beyond this range, the cell structure of wood becomes fatigued and starts to break down.
Wood that has too high an EMC is soft and structurally weak because the cells are full of water. The acoustic properties are dampened, swelling causes stresses where it is glued together (like at the rim or by the ribs) resulting in fractured glue joints and compression ridges commonly seen in soundboards (which will split when they dry out too much).
Too low an EMC creates the possibility of a brittle cell structure. This may be stronger than a too high an EMC, but will result in splitting or cracking if pushed too far.
Swings in EMC only exacerbate all of the above problems and speed up the process.

Hygrometer

RH is measured with a (natural hair or digital) hygrometer. Hygrometers should be calibrated for accuracy once a year. Place the hygrometer on top of a fully saturated sponge in a small, clear and sealed plastic bag for half an hour. The needle should point to 99%. If it doesn't, adjust the needle with the adjusting screw at the rear of the hygrometer. Use a good fitting screwdriver. Dry the hygrometer of excessive water and hang it near the piano. If the humidity in the room drops below 42%, you need to add moisture to the room to bring it back to 42%. If the humidity raises above 42%, you need to lower the moisture content in the room. Your piano enters the danger zone if relative humidity drops below 35% or is above 55%. Placing jars in the bottom of your piano filled with water and newspapers is out of date and delivers too much moisture in one area in the piano and does damage to the soundboard, bridges and strings.

To keep the humidity swings within a safe range in areas where the average local relative humidity (RH) is above 55%, it is recommended to have the humidistat set at 55% instead of 42%. This is especially the case for older pianos and antiques.

Humidifiers

A very effective way to control the humidity level is by use of a humidifier. To keep the entire room (therefore also the entire piano) at a constant and stable humidity level continuously, as an art gallery would have, would be a complex and expensive set-up. Now days, with technology at our fingertips, we are able to deliver at a very reasonable price a safe, even and constant humidity level to your piano all year round. This very popular and effective system is installed inside your piano. It does not treat your entire room but your piano only and is very efective. This Dampp-Chaser^Â® piano climate control system has the advantage of being silent and out-of-sight and carries a 5 year warranty. Today, piano life saver systems protect over 520,000 pianos worldwide.

The system consists of:

A humidistat - This is the brain of the system, which senses whether the wooden parts of your piano are too moist or too dry.
A dehumidifier - Which carries moisture away from your piano using air currents when humidity levels rise.
A humidifier - Which moisturises the dry wood of your piano when the humidity drops below a pre-set safe relative humidity level.

A Dampp-Chaser^Â® system can prevent damage and maintain tuning stability in your piano! It prolongs the life expectancy of your instrument by many years. Major piano manufacturers such as Yamaha, Kawai, Steinway & Sons, BÃ¶sendorfer, Schimmel, Seiler, Baldwin and the Pearl River Piano Group USA agree on the benefits of Dampp-Chaser^Â®. Guus van den Braak is qualified and a registered installer of Dampp-Chaser^Â®.