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How Do I Measure Piano Humidity Swings?

Table of contents for Pianos & Humidity

  1. How Does Humidity Affect My Piano?
  2. How Do I Measure Piano Humidity Swings?
  3. Where Should I Locate My Piano?
  4. How Long Should I Wait After Moving?
Measure Piano Humidity Swings With A Digital Hygrometer

(Click the above image for a Google Shopping search to purchase a hygrometer)


Recommended Humidity For Piano Health

The general consensus is the ideal humidity for a piano is 42%. When humidity lowers below 35% or rises above 60%, the piano enters a danger zone. However, it is the swinging back and forth that damages pianos.

Consistent ~ Year Around Humidity Levels ~ Best For Your Piano

I have read reports about technicians surprised by how well pianos function in a dry desert region where the humidity remains low year around. Maintaining a constant humidity level is the most crucial factor for piano health and piano tuning. However, I do not live in such a climate; and it seems reasonable a consistently dry climate would dry out the wood and ruin a piano. So I suggest making every effort and maintaining humidity as close to 42% as possible. (Click the above Hygrometer image to purchase.)

Monitor Your Piano Humidity Swings With A Hygrometer

As a piano tuner, I wish every piano owner and piano customer had a Digital Hygrometer (Humidity gauge) sitting on top of their piano. Digital Hygrometers or Digital Hygro Thermometers, like the one pictured above, measure humidity and keep a record of the minimum and maximum humidity levels reached since the last time that history was reset. Humidity control is extremely beneficial for the health of your piano, and a convenient place to start before purchasing a piano humidifier or dehumidifier for moisture control is discovering the current humidity levels surrounding your piano.

Many of my customers use Digital Hygrometers to monitor the humidity surrounding their pianos; as a part of my service, I reset the humidity history every time I tune their pianos. That has enabled me to keep a close eye on humidity swings in their home since my last piano tuning service and assists in making recommendations.

Even if, your furnace has humidity control, it is an excellent idea to have a separate hygrometer to measure humidity and record the relative humidity surrounding your piano. I purchased the one pictured above from a piano supply company. However, I am sure you can find one similar by searching via Google here.

Temperature, Humidity, Control In Your Home

It is best to stabilize the environment in your entire home to correct a humidity problem, rather than simply focusing on the environment in the room where the piano resides. Remember, everything in a piano is either made of wood or depends on wooden parts to function; therefore, humidity control in your home not only is beneficial to your piano but helps to prevent future problems with your entire home.

Piano Life Saver

Whenever discussing humidity and how to correct problems, the question usually arises about whether to install a “ Dampp-Chaser Humidity Control System ” or as they are now called “ A Piano Life Saver System.” I have some mixed feelings about them. The Piano Life Saver system controls both the piano dehumidifier and the humidifier. These systems are beneficial to piano tuning and overall piano heath, when the customer maintains them correctly. However, anyone purchasing these systems should be aware of a few potential negatives:

Piano Life Saver Systems

Piano Life Saver Systems

Maintaining A Life Saver Humidity System

Dampp-Chaser systems, while beneficial to your piano soundboard and tuning do NOTHING to protect the most crucial part of your piano ~ the piano pinblock . I emphasize to customers these systems should be viewed as a patch and not a fix to humidity problems, sometimes they forget this vital information and become lax about the environment in their home ~ subjecting the piano to more humidity swings than if they never installed the “Life Saver Humidity System”.

For piano humidity control, Dampp-Chaser systems need to be filled and serviced regularly. The reservoir on these systems (depending on which one they buy) will usually hold two pitchers of water. When the low-water light begins to flash, at that point, they still have about half a tank of water left in the reservoir. While that gives them some comfort if the light has been on for a while without noticing, sometimes they procrastinate filling the tank, knowing they have some water left in the tank, resulting in the system thoroughly drying out. In that case, there is a small potential for damage to the piano.

Dampp-Chaser Humidifier TreatmentAnother problem concerns partially filling the tank. More than a few customers forget to add one complete-whole pitcher of water when the warning light begins to flash. As a result, they watch the light while filling, fearing an over-flow, and just barely fill the tank enough to shut off the light. In such cases, every few days the low-water warning light begins to blink and they refill the tank. They wonder why they have to keep refilling the tank so often, when the only problem is they are not adding the complete pitcher of water. (Note: The pitchers that come with these systems have changed over the years. Some, but not all, pitchers indicate “fill to this line” and doing so, constitutes “one complete-whole pitcher of water” as referenced above.)

Piano Life Saver Systems are also problematic in collecting mold, especially the hose used for filling. However, these mold problems have been partially solved as long as customers remember to add the Humidity Treatment ~ now supplied with new systems. (Click the Humidifier Treatment image to purchase.)

If a customer is knowledgeable and does not ignore these fundamental facts of piano maintenance, and maintains them properly, then Dampp-Chaser systems can serve to stabilize tuning and (while no guarantee) will help to prevent soundboard cracks.

6 Responses to How Do I Measure Piano Humidity Swings?

  • were can i buy hygrometer to measure piano humidity swings

  • Thanks for an informative website that finally answered some questions for me. My piano is dirty and had some mold on it as well as on the keys. It needs work on the action. I am having difficulty getting good answers from anyone. What should I use to clean it? and the keys? It was previously in Florida and has been shipped to me in Colorado. I’ve got humidifiers going in the room, but I noticed some cracks recently in the bench. I am worried about it!!!! It is a 1927 steinway Is it necessarily bad to have the action removed form the paino and replaced elsewhere and then reinstalled in the piano? I just had it shipped to me and don’t want to shipthe entire piano across the country again… .

  • This is good that you have this up there. I tune & repair for a music school in Austin and after setting the pins on a Sherman Clay for the 2nd time in 3 years, then on another piano at the same location, realized that the humidity was likely a problem. Went to Wal-mart and picked up a hygromitor for $6.50 and found 32% — and it’s raining today. I’m going to put one at each school location. And I’m considering picking up a bunch of these to sell to customers.

  • Hi Deborah,

    If it were me, I would buy two Hygrometers and place one on each piano. I would only use Hygrometers that keep a record of the minimum and maximum humidity levels. Then I would do whatever was necessary to keep the humidity as close to 42% as possible making sure not to go over 60% or below 35%.

    If you click on the picture of Hygrometer at the top of this page, the link will take you to a Google shopping search.

    Good Luck! If I can be of help please don’t hesitate to ask.


  • Thanks so much for this article! I just moved from Fla. to dry Southern CA. The piano technician I had for the first tuning here REALLY pressured me to buy the “Life Saver” system IMMEDIATELY. I’m considering a home humidifier or room humidifier and will be happy to purchase a hygrometer, but since I have two pianos I simply don’t have the $1,000. budget to install two of those systems. I’m checking recommendations on humidifers and planned to place one between the two pianos. Given my busy schedule, I’m afraid I’d be one of the non-compliant even if I did purchase the system. I don’t have time to water plants OR pianos! The precious little time I have, I prefer to be actually playing the piano, not messing with this system. Do you think the room humidifier carefully monitored will suffice?

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