Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Temp/humidity control for Mason and Hamlin BB

Hello all. I'm a new member to our forums, and I'm an owner of a recently purchased Mason BB (new). I'd like some advice on a single concern.

We live in a historic home in TX (35 miles SW of Houston) with (at this point) no central heat/air conditioning units. This situation has led me to consideration of a humidity control system for the piano. Of course Houston climate holds significant variance of RH throughout the year. My dealer didn't seem too excited about an installed system in the piano (not sure why - will f/u w/ him), and he likely would have assumed I had a central unit in the home. I'd appreciate hearing from technicians their thoughts/advice regarding Dampp Chaser units or on any other product or solution I should consider. Also, what would be a reasonable installation cost for one of these systems?

Thanks much!

I'm no expert, but I live in NYC and also have a BB. I use a humidifier(mostly in colder months)to raise the humidity and an room AC unit (mostly in the summer) to lower the humidity. Although I am not able to keep the humidity perfectly stable, the tuning on my piano has been extremely stable, so much so that my tech said I could get away with only one tuning/year(I still do two).

Another BB owner here. And my piano tech has repeatedly talked me out of the Dampp Chaser system for my piano. I have a whole house humidifier that I use along with the heating system in the winter. I am unable to bring the humidity as high as might be desired because the room the piano is in is very "tight". If the humidity is very low along with very cold temperatures outside, I will get condensation on the windows. I use an A/C when it's warm. My piano holds tune very well and my tech does not see any problems in the piano due to humidity changes.

This winter has been very cold and dry. And again, I will likely bring up an in piano humidity unit.

Follow the advice of the piano technician who knows your piano and individual circumstances.

RMT,
Am I reading you correctly that you have no air-conditioning in your home? My Texas friends say you need to do something to lower the humidity in the sweltering summer. High humidity will bring lots of problems to your new piano.

Ed,

Thanks for the reply. We do have A/C window units, but there is not a central unit that would help to maintain consistent humidity levels. If not a Dampp Chaser or similar system, we would definitely have a room dehumidifier in that section of the house. I was curious if there are any specific concerns with emplacement of one of the humidifier/dehumidifier units installed in the piano. I assume installation is a fairly simple operation - I'm curious about what people would consider a reasonable installation cost for the Dampp Chaser unit. Are there any problems associated with these units?

Sincerely,

Ryan

I have a DC on my BB. I keep several matched hygrometers for reference - two inside the piano and two outside. I have full house conditioned air year around, but find the DC maintains an even tighter limit on RH variations.

Easy to maintain the DC. Use the recommended chemical additive, change the pads about once a year, keep it filled as per instructions.

Thanks for the vote of confidence prout!

Ryan, When it is too humid and hot it is important to keep the AC running but monitor the humidity and try to keep it consistent. No need to drop it below 55%RH if combined with a DC de-humidifier system under the soundboard.

The thing to remember about wood and changing humidity is that wood will absorb moisture about 5 times faster than it will release it. Thus protecting against humidity spikes is the most important element to RH management and piano ownership.

If it gets dry for a few days the piano will not react very much. If it gets hit with an air mass that is dripping wet-it will react in a few hours.

The biggest problem with Damp Chaser Humidifier/De-humidifier systems are: People forget to keep them plugged in
People forget to keep the water tank full
The wattage of the de-humdifiers most people install is too small
The undercover system is poorly made

Thanks Ed for the information! I think your input will help in discussing options with my tech. Have a good one!

Dear Ryan,
I live in Brazil, and the problem here is humidity, not dryness. Thus, I have instaled only the dehumidifier part of the system (not a Dampp Chaser, but a Moisture King), and it works great!! I'm using it on an Euterpe/Bechstein 5'2'', but my MH BB is arriving next week, and I definetly will install a system on it, too.
Please let me know how you proceeded so far.
Best wishes.

I just received some news about the hand made heating rod used in Brazil,on a vertical piano ,and it was stated that from a 77-80% external moisture, the heating rod (45°c)allowed a lowering from 55 to 67%. More or less what I expected, (about 10% less )as the high range can only be lowered, 55-65% should be considered good in that case.
My concern then is that if any cold "season" the rod will be more efficient and could eventually dry too much.

But I believe there is not such thing as a "cold" season, is it ?.

Well, I live in the southern part of the country, and during winter we can get as low temp. as 5 º C...

Thank you, an higrostat is really mandatory in that case, but probably better to have one you can regulate yourself, not one that aim to 45% that are not really attainable with heating rods during humid days.

Regards

I am not a piano technician. I am a bioengineer who has had to deal with humidity control temperature etc. (Experimental chambers, test chambers etc.) There appears to be a misperception among some technicians I've spoken to about this system claiming that the soundboard gets "cooked" by a DC system. In fact this is not so, the heaters are only on when the humidifier is not running (and vice versa). I have a 192cm piano and have mounted three heater bars in order to keep the humidity down in the summer. My piano is 12 years old and has been using the DC the entire time. No cracks. My piano teachers piano had no DC and the sound board cracked in multiple places over the past year (he has no AC and mostly a cracked window in the winter like most NYC apartment dwellers).

The other misundersting my piano teacher has for instance (I've heard from others too) is that the heaters will dry out the hammers in the summer and because he likes the "bloom" in the sound of more humid hammers - he won't use the dampp chaser in the summer. Again this is not true - the heat is under the sound board and cannot reach the hammers. In fact the heat is very local and serves only to lower the relative humidity of the air that is under the sound board. The temperature rise of the sound board is very minimal. (I'll check using an IR temperature gun later today as I have to get under my piano to try to fix the undergarment in fact.)

Ed is correct - the undergarment system sucks (well Ed wasn't so crude in his appraisal) but really there has to be a better way to attach that speaker cloth.

I highly recommend using the DC ALL THE TIME, not just in the summer, or the winter.

While we're complaining (in case Dampp Chaser co. is listening):

1) the wing nut holding the p-clamp for the water tube is made from steel and has rusted completely on my unit. Replace with #6 stainless steel machine screw and nylock nut.

2) The rivet used to attach the water level sensor is aluminum and steel (no-no) and has also rusted apart - this should be drilled out and replaced with #6 stainless machine screw and nylock nut.

@RMT, you are not likely to see a soundboard crack in the Houston area; we typically don't see low enough humidity to cause that kind of problem. So, you are essentially contemplating the heater bars...I assume...

Contrary to many technicians, I don't believe in those systems. If and when I ever see credible research that shows a benefit to the health of the piano, I am willing to reconsider my stance. Perhaps in extreme circumstances--where no piano should ever exist to begin with--these systems might help to prolong the inevitable. For a yearly climate system like Houston, I see no use for such a system.

Pianos like consistency, both in temperature and humidity. I have personally seen more damage caused to pianos by temperature fluctuations than humidity. Beware: a very small change in temperature--a fraction of a degree--will absolutely change the tuning of the piano. Good concert technicians know how to anticipate these changes with the lights/etc. so that the piano is at the house standard at the time of the performance. Those heater bars are constantly cycling temperature; I see more potential for harm than good, but that is my own experience.

I don't work on a piano with a system like that installed.

I'm sorry A443 but you don't understand how a servo mechanism works. The DC system does not turn a heater bar on and then off and let the underside of a piano cool down. It is cycled constantly between off and on with a duty cycle that is required to maintain the humidity constant and therefore the air temperature under the soundboard constant..

Again - the thought that the heater bars are raising the temperature of the soundboard is a gross misunderstanding. The heater bars are fully 10" away (or more) from the soundboard and have an effect on the air's moisture content. That's all.

You are also misunderstanding the relationship between temperature and humidity when you state that temperature causes more harm than humidity. In fact a piano is better off over-wintering without heat than with heat, for the precise reason that as the dew point drops you need to actively ADD HUMIDITY if you RAISE TEMPERATURE. So leaving a piano in an unheated house all winter is better for the piano that leaving the heat on in the house all winter (assuming you are in a climate where winter is cold) because raising the temperature affects the relative humidity.

The heater bars are maintaining constant temperature, they are not cycling hot and cold and please cite your "evidence" of damage to pianos from a DC to the contrary. This discussion deserves better than an opinion. So far what you've posted is misinformation.

Grotriman, calm down and slow your roll, just a tad; if you want to have a dialogue, that's great.

Do you have experience with, say a 1 degree shift in temperature, changing the tuning of the piano? Let's start there....

A443, I have read statements like yours a few times now on PW criticizing Dampp-Chaser systems. I certainly understand your desire to see more scientific research demonstrating the value of the system; I am not aware of any extensive third-party research that has been done, although anything conclusive would of course have to test a large number of pianos over the course of many years.

With that said, I also respect my own positive experiences with the system, as well as the opinions of countless other professional technicians and piano manufacturers (see this page - I don't think they're making that up).

Since your argument is also one primarily from experience, would you mind sharing what negative experiences you have seen as a result of the Dampp-Chaser system being installed on a piano? Of the negative comments I have read about Dampp-Chaser, I have never heard any that weren't primarily the result of improperly installed or improperly used systems.

Thanks BenP for initiating a calm discussion!

Let me try to be clear: I have had absolutely zero negative experiences with the Dampp-Chaser system. My negative experiences have been with temperature, in general.

I know first had what HVAC systems with broken thermostats do to pianos in an institutional setting (i.e., on the cold side), and I know very well how stage lights (i.e., heat) effect my concert tunings--for which I have learned how to compensate so that the piano is at the correct house standard when the piano is used, not the moment I tune it!!! I have experienced how extreme temperature causes great damage to a piano. READ: this does not mean that I think a Dampp-Chaser system causes problems; since the data is lacking, I choose to take a cautious stance and refrain in participating in and recommending such a system. No one should have a problem with this.

Furthermore, I was at a convention probably a decade ago and the Dampp-Chaser company supplied the attendees with the temperature/RH data of their own experiments. Temperature, according to their own data, was absolutely cycling up and down; that was enough to give me great pause! I simply want to remain cautious until I see more data.

The other thing I'd like to point out is that the majority of my own observations have been done in areas in the world that do not experience 4-season weather shifts. Humidity, for the most part, stays c.50-60% on the inside all year round (i.e., perhaps only 1-2 weeks does it drop to 30%). That is the background of my experiences.

I welcome further discussion...