• Piano Department

    April 2, 2020

    Let’s talk ‘humidity and acoustic pianos’

    Like the majority of the UK right now, members of our team are working from home. We are still working to help to support our lovely customers from home and I happen to be one of them. Where I would normally be working full time in the acoustic piano department at Forsyth, I am now making the most of this terrible situation staying at home, sitting in the sun whilst doing what I love most. Talking acoustic pianos!

    Although the weather was lovely last week and gave the UK a much needed moral boost, it can also come with some bad news for your treasured acoustic pianos. Glancing over at my pride and joy, as I often do and which usually brings a smile to my face, kicked off a mini panic. Here you can see a picture of the hygrometer currently sat on my piano at home.

    A hygrometer is a device that measures both the temperature and relative humidity in your home. Most piano manufacturers recommend keeping pianos between a relative humidity of 40 - 60% and as you can see, mine is currently reading an almost Saharan 35%. It even reached as low as 29% yesterday, which is well into the red zone!!!

    Considering that the primary material of a piano is wood, then it is not surprising that humidity plays such a huge part in the proper care and maintenance of your instrument.

    Now for the “sciencey” bit.

    We have many of our customers who aren’t sure what relative humidity is and why it can badly affect pianos. I will explain:

    Relative humidity is the ratio of how much moisture is in the air compared to the maximum amount of moisture the air can hold. The absolute amount of water that the air can hold varies depending on its temperature - the warmer the air, the more moisture it can hold. This means that with this beautiful weather, the sun is blasting down and heating up the air enabling it to hold more moisture than before. This change actively decreases the ratio of how much water is currently in the air to what it can actually hold, therefore creating a much drier environment for your piano.

    When the air has a lower relative humidity, this in effect draws moisture out of the wood in your piano causing it to shrink/contract. When the humidity increases again, this will then allow the wood to absorb moisture causing the wood to expand. It is this constant change in relative humidity that affects the tuning of the piano as well as the regulation of the action. When the humidity is extreme - too high or too low for extended periods or wildly oscillating it can cause irreversible structural damage to your piano. This can cause the wood to crack, split and even warp, regardless of whether the piano is a budget piano or a handmade concert grand piano made in Austria!

    The weapon of choice to combat an excessively dry environment is a humidifier. For those who suffer from the opposite with excess humidity instead, you will need a dehumidifier. There are plenty of humidifiers, dehumidifiers and combinations of them both in one available on the market. Some of the top end models have a built in humidistats that will automatically control the environment, while the others are much more basic. These devices are generally used to treat the room as whole, which is definitely advisable for grand pianos and has the added benefit of helping other wooden items in the room like furniture! As we don’t sell them at Forsyth, we unfortunately do not have recommendations on particular models, however there are plenty of reviews out there and devices to suit your budget.

    The humidity in our showroom is on the low side, most of the time, so to combat this we have some industrial humidifiers, which would be overkill in your own home. We also have some smaller models which we picked up from Maplins, before they shut down. A customer of ours recently contacted us about what we would recommend. We sent him the specifications of Maplin’s own humidifiers, which he used to source his own. He wrote back to us to say “I have ordered the ‘PureMate PM-906 Digital Ultrasonic Cool & Warm Mist Humidifier with Ioniser’.  The company Pure Mate has been very helpful. When it arrives, I will let you know what I think of it. It costs £79.99, with free delivery (a bit extra for delivery to Ulster, Northern Ireland)” We will report back ourselves when we hear from him!

    The other way to try and improve your piano’s environment is to use a piano specific system such as a Dampp Chaser, “life-saver” system or an in-piano humidifier tube.

    If you know you suffer from low-humidity, you can purchase a piano humidifier tube. As it explains on our website, the piano humidifier tube is a simple but effective way of adding humidity to the environment within a piano. In many homes with central heating the relative humidity can drop to levels that can cause structural problems with pianos (i.e. below 40%RH). By using this tube, which is manually soaked in water then placed in the piano, you can effectively create a micro-climate in an upright piano. These are priced at £46 and are very easy to install inside the bottom of your upright piano. Please follow the link above to order on our website now.

    At the other end of the spectrum with high relative humidity, there are low energy heater bars that you can again fit into the bottom of your piano, which will help to keep the relative humidity levels down. Like the humidifier bar, the enclosed nature of an upright piano helps to create a microclimate that will protect all the internal guts of the instrument. In their simplest form the heater bars can be plugged in and you have to decide when to turn it on and off. These are easy to self install and are £52. Alternatively there is a ‘humidistat’ controlled system which does this for you for £156. These will shortly be added to our website, however if you would like to order one of these please email [email protected] Keep an eye out on our website here for when they are listed.

    A grand piano works a little differently as you can’t create the same microclimate effect that you can in an upright so we would always recommend treating the room as a whole if possible. If not, you can use a Dampp Chaser Complete climate control system (i.e heater bar and humidifier within the climate control system).

    For an upright - This will protect the piano for those whose environments are constantly changing. When the humidity reads above 45% the low emission heater bars will kick in to eliminate excess humidity. If the relative humidity reads below 45% this will turn on the humidifier system which introduces moisture into the air to protect the piano. These are available for both upright and grand pianos, starting at £388 for an upright and £422 for grand pianos up to 5ft and £494 for grand up to 6ft. For larger grands you may need an additional heater bar at the back of the piano. Again these are provided with some very easy instructions for self installation, however we are able to come and fit these if required at an extra cost and depending on location. You can see these on our website.

    If you have concerns about the humidity in your home, you can easily measure it with the same hygrometer device that I have. These digital hygrometers, which record the maximum and minimum temperatures and relative humidity, are much more accurate and give you a better understanding of how the conditions change over time rather than one off readings. We have plenty of these in stock and you can purchase these on our website

    I hope this information is helpful and easy to understand. Let us know how else we can help!

    For further details, enquiries or if you would like to place an order, please email [email protected] or call on 0161 834 3281 extension 5 for more details.

    If you have any further questions regarding purchasing or renting acoustic pianos, please contact the piano department on 0161 519 1996.

    In the meantime, stay at home, stay safe and keep playing!


    Senior Piano Sales Consultant