Instructables

An Easy-to-make, Energy-saving Piano Humidity Control System (dehumidifier)

Picture of An Easy-to-make, Energy-saving Piano Humidity Control System (dehumidifier)
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In this intructable, I'm gonna show you how to build a simple dehumidifier for your precious piano, at a fraction of cost if you buy a similar product. And it uses much less energy than a room dehumidifier does.

We bought a new piano last year for my son. When the tuner came for his first service, he told me that the best humidity level for a piano is 42% to 45%, and he recommended us to install a piano humidity control system - Dampp-Chaser. Their website has an excellent description of the benefits of this system. http://www.pianolifesaver.com/english/benefits.php

I won't repeat all the benefits here, but just in summary:
- stabilizes piano tuning, so you can see your tuner once a year or even longer, instead of every 6 months. This saves you about $100 a year.
- save hundreds of $$$ a year compare with using home dehumidifier

But the cost is over $600, and maybe up to $900 to have it installed!!!

I've used the last penny for the new piano, but the Dampp-Chaser seems promising. So I decided to make my own one.

Stay turned. Here comes my design.
 
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Step 1: Design

Picture of Design
heater.jpg
sensor.jpg
TH controller_2.jpg
RHC-Schematics_0001.jpg
***************************************************
******* WARNING AND DISCLAIMER ********
===========================
THIS PROJECT INVOLVES 120VAC CIRCUITS.
FIND A QUALIFIED PERSON TO HELP YOU
IF YOU DON'T HAVE ADEQUATE KNOWLEDGE
AND EXPERIENCE ON IT.
THE AUTHOR TAKES NO RESPONSIBILITIES
TO ANY PERSONAL HURTS OR DAMAGES
TO ANY PROPERTIES.
***************************************************
First of all, this system is for acoustic pianos. If you have an electronic piano, never mind. You'll never need tuning, so you don't need it. And it's for upright pianos. I don't have a grand piano to play with.

As looked into the Dampp Chaser system, I decided to get rid of the humidifier part, just to make the dehumidifier part. To avoid to be too boring, I put all the detailed descriptions and explanations in the last step. Find them there if you are still interested.

Therefore my humidity control system is actually a dehumidifier - to be used in summer time to keep you piano not too humid inside while you can also be comfortable outside in a room.

Here's what the system will consist. It's really simple.
- a humidity sensor to sense the humidity inside of the piano
- a heater inside the piano to reduce the humidity when needed
- a RH controller to control the heater

See attached pics for my design. And you can also download the attached pdf file for the complete design that includes dimensions the parts you need to make.
TH controller_2.pdf(789x792) 1 MB
martyjandrews2 months ago

I can't seem to find any reasonably priced thermostats with RH control. Can you tell me what model NOMA you used? Thanks!

fbartlett3 years ago
The design is straight forward, but the heating elements could be replaced with a more efficient heating source. Got any better ideas? The retail ones just use a 15 watt electric heating element to do the job, so why use 400 watts of IC bulbs? It would dry it out really fast but do you need that much heat?

Technocrat
Taotaoba (author)  fbartlett3 years ago
I use 4x100W bulbs, but please note that two bulbs are connected in series and then in parallel. Therefore each bulb will work on 25W (approx.), total power is only 100W. The reason to do it this way is to bring down the temperature of the bulbs.

I don't know if the 15W will be enough, because my calculation sugguested 50W. With 100W, I can get some "engineering margin", and the heater doesn't have to work that hard. In really humid days (>70%), it works on 80-90% duty.

This system has been in service for my piano since then, and it really does it job, keeps my piano in good shape. Cheers!
Hi,

I have just bought a baby grand and concerned to use a system for humidity control. I note several articles mention using heat to control humidity.
Having taken weather courses (I have a sailboat) heat increases the amount
(percentage) of moisture in the air. Can you explain how a heater reduces humidity. A dehumidifier uses a refrigeration unit to decrease humidity.
In Ontario, Canada, our summers are very humid, and winters very dry, so we need a system to both moisturise and, remove moisture. Perhaps I'm misunderstanding something but at this moment a bit confused.
Would you explain for me please how heat decreases humidity?
Thanks,
Ken
lilycjwang4 years ago
Very good idea and clear instructions. i might ask my husband to build one for me.
Myself5 years ago
Cool, that's the third nontraditional use for incandescent lightbulbs I've come across recently. They're easy to work with, aren't they? How do you feel about the cycle length of roughly 2 minutes? It seems like the relay and bulbs might not last too long, being operated so frequently. But if you slow it down (by partially enclosing the sensors?), it would mean the wood in the piano would "feel" the fluctuations more. Suppose you had four humidistats, each connected to its own heater, and made their setpoints 40%, 42%, 44%, and 46%, or so? You could probably find an equilibrium state where the appropriate number of bulbs ran constantly, relays operating only when the room's humidity changes.