Measuring Humidity and Pitch of Your Piano

In my last post I talked about the importance of humidity when it comes to pianos staying in tune. Here is an inexpensive hygrometer (humidity measuring device) that is available at Home Depot for around $10. 

It is called the ACU-RITE Backyard Weather Humidity Monitor 

The readout gives current relative humidity and temperature and also tells you what the high and low have been in the last 24 hours. These inexpensive hygrometers are not known for their precision. However, for the purposes of protecting the stability of your piano's tuning, absolute accuracy is not of paramount importance. Having a generalized idea of what the humidity is doing is the key.

For more detailed information and greater accuracy, for around $100 I highly recommend:

Lascar EL-USB-2-LCD

These can be purchased through Amazon (which may be the most inexpensive) or directly from Lascar Electronics. The really useful aspect of this device is that it can be set to take several readings every day over a period of weeks or months. Then you can plug it into your computers USB port and view a graph that will show you the temperature and humidity over that period of time. This short video shows how this feature works. 

The whole point of measuring the humidity is to stabilize the piano's environment thus stabilizing the tuning. Another helpful tool in helping you achieve this goal is to actually measure a note on your piano with a free tuning app. My favorite for Android phones is Tunelab, which is actually professional piano tuning software that has a shareware version. The limitation of the shareware is that it times out every so often.  (I think around 17 note switches causes a  time out for 2 minutes). 

It would be best to measure a note right after the piano has been tuned. The best note to measure is lowest plain wire string, which on most upright pianos (and smaller grands) will usually occur somewhere around the F note below middle C. The lowest plain wire note will usually be the one to react the most with humidity changes. The reason has to do with the wire's tension and how close to its breaking point it is. Wires that are closer to their breaking point are more stable than lower tension wires. Another approach would be to just measure all the Cs on the piano and write down the frequency number. In the above picture the frequency of C5 is 528.58 Hz. 

If you see the frequency of a note dropping, it's an indication that the piano is losing moisture. The exception to this is with newer pianos or pianos that have new strings. They will tend to drop in pitch quite a bit for the first couple of years. However if the piano was tuned during a humid time of the year, you will expect the pitch to drop during drier weather. If you notice the pitch dropping, it is a good idea to run a humidifier in the room to bring it back up. However, in very cold weather there are limits to how much humidity you can add to a room, without causing moisture problems in the house. Here are some guidelines [source Home Energy Resource MN]:

    Outside Temperature                        Inside Humidity

                        20º to 40ºF                                          Not over 40%

                        10º to 20ºF                                          Not over 35%

                        0º to 10ºF                                            Not over 30%

                        -10º to   0ºF                                         Not over 25%

                        -20º to –10ºF                                       Not over 20%

                        -20ºF or below                                     Not over 15%

During very cold weather, if you are unable to add enough humidity to the room to keep the piano's pitch from dropping, than adding a Dampp-chaser system with a humidifier will help. It will add the humidity directly to the piano instead of the room. 

 Likewise if the frequency/pitch of a note is rising, it is a sure sign that the piano is taking up more humidity. Installing a Dampp-chaser system can bring the pitch back down if the humidity is running in the high 40's or greater. 

Paying attention to the relative humidity and the pitch of your piano will give you clear information on how humidity and tuning are related. Preventing rises and falls of pitch by controlling the humidity in the room and/or piano will help you get the most musical enjoyment and inspiration from your piano. 

Humidity and Your Piano's Tuning

Why pianos go out of tune

The top 3 reasons are:

1. Humidity Change

2. Humidity Change

3. Humidity Change

The “Dirty Secret” of Piano Tuning

“If you wait longer, it may actually get better!”

Could this really be true? Could a piano be in better tune after a year than after 4 months. I can assure you that it is certainly true, and I have seen it many hundreds of times in my 20+ year career as a piano technician.

When I see a piano in exactly one year, it is almost invariably in better tune than when I see it after a few months.

Why? The reason is the average humidity at any given time of year is similar to that of previous years. Not exactly, but similar enough that the tuning can correct itself to a surprising degree.

For information on pitch and humidity measuring devices please visit my post on this topic: Measuring Humidity and Pitch of Your Piano

Q: What’s the ideal humidity level for a piano?A: Between 40 and 45 percent

“A relative humidity level (RH) of approximately 45% is ideal” - Kawai owner's manual “Generally speaking, a relative humidity of between 40 and 45 percent is ideal for pianos." - Yamaha’s official website Manufacturers like to say that the temperature should be at 72 degrees F. and the humidity about 45 percent. -Larry Fine’s Acoustic Piano Buyer

Humidity Trends in the Pacific Northwest

I regularly measure humidity in my clients home, and over the years I notice pretty consistent patterns. In the summer, the relative humidity often averages around 65 percent dropping down to around 55 percent in the late fall and finally down to the 40’s in the winter. Occasionally we get humid spells in the summer with the humidity jumping up to 70 or even 80 percent. Likewise, a good cold snap in the winter can drive indoor humidity down into the 30’s.

Rule: the colder it is outside the drier it is indoors.

Cold air can’t hold as much moisture as warm air. When cold air is brought indoors and heated to around 68 to 70 degrees, its relative humidity drops significantly. That is why winter is the driest time indoors.

Fortunately for us in the Puget Sound, indoor humidity during the coldest months is close to the ideal of 45 percent. However the gradual increase in humidity from Spring into Summer is where problems arise.

A basic piano humidity control system is designed to take care of the piano during the summer months when average  humidity typically runs in the 60-70 percent range.

Don’t throw away your tuning dollars!

Believe it or not ~ I have seen pianos literally go out of tune in a week due to sudden humidity change.

A True Story

My most talented client ever, Charlie Albright, lost power in his home in Centralia one winter. The house got very cold. When the power came on Charlie called me complaining about how bad his piano sounded. I told him to wait a couple of weeks and check in with me again. After two weeks Chalie called to say “it sounds fine now!”. If I had tuned the piano right after the power came on, it would have quickly gone out of tune.

I take a great deal of pride in the quality and stability of my tunings. However, the most stable tuning in the world will only last as long as the humidity remains at the same level as when it was tuned.

A Dampp-Chaser system is one of the best assurances I know of to preserve the quality of my tunings. That is why we put them in the pianos we sell. That is why I recommend them to all my clients. Consistently the pianos that have a system are in much better tune when I arrive to service the piano than those without. This gives me more time to address other service needs of the piano besides tuning: Cleaning, voicing, regulating, etc.  

Another true story: I arrived at a local piano teacher’s home during the summer  to tune her grand piano that I had tuned the past January. The piano had gone significantly sharp with the higher humidity and the tuning was really bothering her.  After some discussion she agreed to forego the tuning and instead had me install a Dampp-Chaser system. 2 weeks later at the monthly Olympia Music Teacher’s Association meeting, she was happy to tell me how much better her piano sounded already! The system dried the piano out and made its humidity level closer to where it was when it had last been tuned.

Q: “Won’t these humidity control systems put you out of a job?”

A: The systems are not perfect. It is true that a piano owner may find he/she can greatly extend the interval between tunings. However, tuning is just one aspect of the maintenance of a piano. When I show up to service a piano that has a system installed, I am usually able to spend more time cleaning, controlling friction, and regulating touch and tone.. These are separate issues from tuning yet are equally important in order to get the most enjoyment of the instrument.  

How much do they cost?

• A basic upright system costs $257 + tax (includes installation)
• A basic grand system is $305 + tax for pianos under 6’. Pianos greater than 6’ are $380.
• We recommend having the piano tuned 3-4 weeks after installation. We give a special tuning rate of $140. (this is strictly tuning - no additional maintenance or repairs included. It is to compensate for the effect of the system)

Suggestions for keeping your piano in tune:

• Get a digital hygrometer and put it near the piano so you can actually watch what the temperature and humidity are doing.
  
  
  
  
• Get a free tuning app for your smart phone or tablet computer that will allow you to measure the low, middle, and high C, so you can see how humidity change is affecting the pitch of these notes.
  
  
  
  
• Run a humidifier in the winter if the humidity is getting below 40 percent.
  
  
  
  
• Using an air conditioner in the summer months will keep the humidity closer to the ideal range.

• Keeping the room cooler during the coldest months of winter will actually keep the piano for getting dried at as much.
  
  
  
  
• Keep the piano away from direct sun and heating vents.
  
  
  
  
• Avoid having the piano tuned right after unusually humid or dry weather.

For less than the cost of 2 tunings, you can help insure the tuning stability of your piano and improve your listening pleasure throughout the year

“It’s the closest thing to having a tuner living right inside your piano!”

Pianova Piano Service

360-705-4160

800-972-8863

ryan@pianova.net