I have a newish Perzina 122 upright. I had it tuned once after delivery and it was on its way out of tune again by 6 months so I've just had it tuned again. the tech who did the work strongly suggested that I get a damp chaser.

I've been considering this anyway but one thing he said struck me as exaggerated. He claimed that he hasn't tuned his own piano in 3 years and it's still in tune due to the damp chaser - is this possible?

lmao...

3 years? I personally don't think it's possible.

Get another tech.

But for the sake of conversation, how much difference would it make? My house is a drafty old thing: dry in the winter (though I have a humidifier in the room with the piano lives) and humid in the summer ( no air-conditioning).

3 years is not out of the question if the piano was in a very controlled environment and not rigorously played. I think the advice to get a new tech is a little harsh. I think the point here is that (when properly maintained) a dampp chaser can do a lot to improve tuning stability on a piano. I don't think a piano *needs* a dampp chaser. Kind of like a car doesn't need cruise control or a stereo:)

Quite a rash statement.

It isn't all that uncommon for a piano to hold tune for several years if the environment is very stable.

Not very common, but not that rare.

jnod,

No A.C. hmmm...I've been in Toronto during the summer. It can get sticky.
You could get a room de-humidifier. It is effective in removing excessive moisture from the air but it can be noisy and the bucket that collects the water must be emptied each time it fills. Unless, of course, the unit is connected to a drain via a hose for example.

Does your tech happen to sell/install dampp-chasers?

Even if his 3 year claim is "truthful", I don't think it's reasonable for you to assume that you will reap similar rewards.

fingers

The technician may be deaf!

Ok tuners, let's not hold back: how often do you tune your own piano? I'll go first. I last tuned my piano (a little Winter upright) 2+ years ago. It's not that it's held its tune for that period (it most assuredly has not). I just don't feel like tuning when I get home. Just sayin.

Tuning stability is just one benefit of a Piano Life Saver system. I would say a bigger benefit is protecting the wood and glue joints from damage caused by humidity cycles over time. Do your kitchen chairs have loose cross-braces between the legs? It's probably because winter dryness shrinks the wood so much that the glue joints break.

The more stable the tuning, the less the pins have to be twisted to make adjustments, and so the less wear on the pinblock. Most people keep their pianos 20 years or more, so it's an investment for the long term (like keeping a car in a garage instead of outside in the sun and snow).

--Cy--

P.S. I tune my piano every six months or so. I'm trying a variety of historic temperaments. I like the Bach-Lehman; it's a mild one (see http://www.larips.com).

Disclaimer: I sell and install Piano Life Saver systems. But I have them on all of my family's pianos, too.

I hope y'all don't mind if I ask a side-question -- a general question about Damp Chaser:

Can it do any HARM?

That's what has kept me from getting it -- the fear of harm. It just strikes me that putting basically a tub of water right up near the piano might not be too safe.

I assume I'm being an idiot but just wondering.

Mark,

This is a very good question, and something I have been commenting on for a very long time.

Depending on where you live, there are going to be fears about either too humid, or too dry, a climate.

There is a much greater chance from what I have seen of the climate control system introducing too much dryness to the piano. They have dried out many a piano over the years, especially since many 'technicians' did not install the thermostatic control (humidistat).

As far as introducing moisture, I don't think it would be nearly as much of a problem for the piano as too much dryness.

THANK YOU for the great post.

I just learned something -- and I imagine many people might have had no idea about that.
It seems very ironic that the main danger might be dryness.

One more thought:

In case a piano owner is concerned, it should be noted that too much humidity is much more easily detected than too much dryness.

Excessive humidity will cause NOTICEABLE problems such as sluggish keys and action, corrosion, etc.

On the other hand, dryness just dries, and dries, and dries... until CRACK! And it's too late to do anything about it.

Be most concerned about too much dryness. Humidity (moisture) can be a good thing! And this is from someone who lives in Florida.

Thanks again......The thing I'm mainly worried about is something a bit different: A whole bunch of water sloshing against the piano. Or something of that sort.
i.e. Not merely "too much humidity," but A HUGE AMOUNT too much moisture, because of some malfunction.

Moisture tends to be 'absorbed as needed'.

That's quite a different story than a heating rod, uncontrolled, baking your piano!

I believe that the OP has a point ... what chance is there of this Dampp Chaser system going wrong and either baking the piano dry or making it too humid?
I have had fitted a Dampp Chaser system to my upright.... and was surprized that the heater rod was on much of the time when the room humidity was in the low 40's % RH. However I have a humidity sensor with a remote readout that I fitted in the piano (on the opposite side of the water reservoir) and found that inside the piano the RH was between 54 and 57%... so the wood itself is fairly humid and the Dampp Chaser system is gently drying it out... which is fine..
Given this I am happy that I have this option to monitor the humidity inside the piano - and recommend other paranoid individuals to do the same. It should be noted that the heater bar is not so powerful that it will cook your piano overnight.
The Dampp Chaser warrantee covers the malfunction of the DC system - and will cover the cost of a new system - but clearly states that it does not cover any damage to the piano caused by the malfunctioning system.
In my case - I want to stop large swings in the humidity so that pressure ridges on the soundboard do not build up. The secondary aspect of less frequent tunings is a side effect that I am happy with - but in reality I enjoy the visit of the piano tuner.
One does not have a bucket of water sloshing around in the piano ... just a small reservoir that sits in a corner inside the piano... at least this is the case for an upright.

all very interesting - thanks everyone (you too side-poster). I hadn't considered the possibility that the thing could actually hurt the piano though I'm, of course, always glad to have something new to worry about.

The truth is that my house does have pretty significant swings in humidity - Toronto does range from volcanically hot and humid to dry and frozen solid. Maybe I should just move eh?

I have a 102 year old Everett upright with a Dampp Chaser and my piano technician is always impressed with how little he needs to do in adjustments every tuning session.

I'm a student at Frederick Community College. Every grand piano they own has a damp chaser installed, eccept for the Bosendorfwe Inperial, which has 2! Several of the uprights do also.

My piano does as well (no, not the Clavinova).

I'm very pleased with it.

Jnod:

1st, the new systems can be ordered with the 'smart' feature that turn of as a fail-safe if certain events happen.

In Toronto they are of great benefit, especially in an older house. 1 example, a 26 year old Young Chang grand in an old house in Forest Hill fitted with a Pianocorder. This piano had a d-c installed 25 years ago and in the 1st 7 years of its life was tuned frequently and all recommended maintenance was performed. I recently appraised it, and it had not been tuned for about 8 years. It was on pitch and the tuning was quite good, no unisons out and no octaves out more than a cent or 2, tight tuning pins, good bridges, action good and soundboard with no pressure ridges or cracks. I would strongly recommend one for your situation. There are always those who can come up with catastrophic 'what if' scenarios. Howver, I have never heard these scenarios from any veteran technican who service these units. You see, your ceiling could fall down or your floor could collapse, or perhaps an airpane will crash in your house and damage your piano. Get the unit from an experienced installer. It will save you money and your playing experience will be enhanced too.

Steve

A D-C doesn't do harm, if it's installed by a piano technician, and it's not older than, say, 30 years (they've been around for 60 years). There's a lot more risk from letting your piano dry out every winter. Did you notice I have them on my own pianos?

My mother used to put a jelly jar of water in the bottom of our upright, which would evaporate in a few days and have little effect (with most D-C systems on the east coast, you use up about three gallons of water a month). And sometimes she'd leave a light bulb on inside the cabinet, a steady heat source without any control unit.

Check out their website and make up your own mind.

--Cy--

Have 2 pianos... a grand with a dampp chaser and an console without. The grand holds its tuning pretty well but I still get it done at least twice a year. Usually more often because I'll have it done for any recording sessions where I have my tuner present who even tweaks it on breaks.

Also have an April-Air on the furnace which, if you have forced air heat, is another thing to consider. If only for your general health as well as that of your furniture and kitchen cabinets. I don't think an April-Air is sufficient but it helps smooth out drastic fluctuations which helps my console hold its tune. I also had the opportunity during a rebuild a few years ago to send my console's replacement strings to a cryogenics lab... a treatment which also tends to help strings hold their tuning in a different way.

I agree with what has been said about how excessive dryness can damage wood. You definitely shouldn't skimp on the control circuitry and by all means, refill with water when it runs out. Typically every 2 weeks. I consider your lack of central air a plus because high humidity in the summer is really only an issue if you get condensation. Which may lead to string and pin corrosion. The dampp chaser can easily control high humidity anyway. But there is another thing to consider about the dampp chaser installation. Make sure that the water tanks aren't too close to the strings or frame or you might get water-tank condensation on them. Which is the reason I didn't dampp chase my console... there just wasn't enough room inside to mount the tanks much more than an inch from the strings and I don't want them mounted outside.

Howard

I swear by my DC on my last two pianos. The new one does indeed have an indicator that shuts it off if no water is wicking up through the humidifying pads. This is a safety feature against over-drying. There is a little "hat" thing that catches any condensation so it wouldn't happen on the sound board.

I would have strong doubts about any piano claimed to be in tune after three years or any tuner who made the claim...but stranger things have happened. And there is a wide variation on what people consider "acceptable".

Many words have been written on this forum over the years on this topic and I will once again relate our experience.

We live in a very dry winter environment and the recommendation of our technician was to look first to whole-house humidification system, rather than a D-C (which he sells and installs). His reasons were: with a grand piano this provides humidity control to the action stack in a way that D-C cannot, you are providing protection to everything in your house and they require less TLC than a D-C, for example when you are on holidays. Now with this recommendation comes a lot of caveats. Your HVAC system needs to support always-on humidification (and there are a number of different types) - in our case constant air circulation over a waterfall type humidifier. You also need humidity control. We have an relative-humidity controlled air-to-air heat exchanger, which in combination with air-conditioning in the summer provides ample high-humidity prevention.

None of this is to say a D-C isn't a good choice as either primary or supplemental environmental control for your piano. It is just worth evaluating if the money spent on a D-C might not be better spent on whole-house control if that option is available.

That's another way to put it!

Steve, I don't think it's rash considering the premises and the exaggeration.

Even if a piano is in a 100% controlled environment, I think it's still not possible for a piano to hold the EXACT same tune for 3 years (i am talking exact frequency here). There's always deviation no matter what.

This does bring up an interesting question. What is considered "in tune" ?

Thanks everyone for a really interesting thread. I live in Chicago which has a climate similar to Toronto. My grand came with a Damp Chaser already installed. Interestingly, my technician dislikes them and favors room humidification instad. This is what I've ended up doing: in the winter I have two room sized humidifiers and the Damp chaser turned on. The Damp Chaser is serviced by a different technician who just attends to it. In the summer I turn them all off, in line with the observations that summertime humdity is probably less dangerous. I've been happy with tuning stability, and I'm hoping the evils of dryness will be avoided!

Best

Thank you! I appreciate that very much.
It's part of what I was wondering about, although I wasn't able to articulate it at all -- the idea that the DampChaser doesn't give uniform humidification to the piano.

Granted, few people have a real option for whole-house humidification, and it's not what I have; in the absence of DC, I'm just using regular store-bought humidifiers, and I realize the DC is probably far superior to what I have.

But I'm not sure. And, the nature of the DC is such that I would worry MORE about uneven humidification, because of the proximity of the unit to the piano, than with plain humidifiers, which are at least some distance from the piano.

I aim for the humidifiers to provide sort of quasi "whole-house" humidification in the vicinity of the piano; this at least gives a humidification that is fairly uniform throughout the piano.

Great point. Really.

Not only do different people have differing sensitivities about it, but probably each person has differing sensitivities depending on the moment.
I get much more persnickety in the immediate period before a performance. And if we have to make an audition tape (or whatever), we're probably even more persnickety.

Wow! You have "it all"!

I'd guess that's 'fairly unique.'

It's understandable to be concerned about a tank of water near the piano, but D-C has figured it all out in the 60 years they've been in business.

First, for grands there is a shield that protects the soundboard from direct humid airflow. Next, on all systems, the humidistat continuously cycles between the wet side of the system and the dry side, so that many times a day the heater bars come on, even if just briefly, in order to circulate the air and to prevent condensation.

I'll be the first one to say that whole-house humidity control is the platinum option. It's what museums use, and it typically costs like platinum. If you can do it, great. Be aware that high humidity in winter in a cold climate can cause condensation and water damage on interior walls.

The bottom line is that humidity control is a grey scale: you don't have to be perfect to make an improvement. Even museums don't get to 99.99% control. Whatever steps you can take to keep indoor relative humidity somewhere between 40% and 60%, your piano will last that much longer. And if you can keep it within, say, a 10% range between 40% and 60% (like 42% to 52%), that's the ideal.

Many people use a combination of a D-C system for the piano, and a supplemental humidifier in the winter for the room and your own comfort.

But I'm an unapologetic fan of the Piano Life Saver system. It has no moving parts, it's completely quiet, it uses little electricity, and it needs very little maintenance. Whole-house alternatives have none of these advantages.

--Cy--

Thanks for this additional great reply.

And let me ask this, to you and anyone else who might have an idea:

In view of "whole-house" being the ideal thing.....Don't a couple of well-placed store-bought regular humidifiers accomplish the same thing as "whole-house" humidification, provided we make sure that the humidity in the whole vicinity of the piano is in the optimal range?

And if so, what is the advantage of a DampChaser over that?

I sounds to me like the biggest difference is the effect of summertime humidity.

Many piano stores use exactly this method in the winter. It's a good solution for them: they have multiple pianos in a small space, and they can afford to keep them running. It's cheaper than installing D-C's in every piano.

But when people want to play, they often have to shut them off, because they're noisy. They run out of water in a few days unless they're plumbed into the water lines. You have to be careful not to arrange them so that mist lands on the pianos and makes water spots (I think it's the ultrasonic kind that have this tendency -- is that right?). You have to maintain them: keep the filters clean to prevent mold buildup. And they cost more in electricity to run: D-C has done some studies on their website.

Oh, and then what do you do in the summer? Use a couple of store-bought, well-placed dehumidifiers, right? Noise, expense, and maintenance again (and they fill up in a few days and shut off).

I spent four winters in Minnesota (we don't say "years" :-), and I was looking at a whole-house system myself. The advantage is that everyone is comfortable in every room (and the furniture). I used to get painful cracks in my fingertips that affected my tuning (Liquid Skin helps!). My furnace didn't have a two-speed fan, so it was going to be a lot more expensive than I thought.

--Cy--

Thanks SO much for this great, comprehensive reply -- and really to everyone on here for helping us understand more about the ins-and-outs not only of DC but of this whole subject.

The noise is no issue for me, for an odd reason: Due to allergies, I have a very noisy air purifier in that same area, so the extra noise from the humidifiers is negligible. I know that this won't apply for most people.

About having to keep putting water in the humidifiers: I 'assumed' you have to do that too for DC!! Although I did wonder exactly how that's done.
So, do you mean the DC is "plumbed into the water line"? Sounds like it -- and this would give me a whole new range of paranoid concerns.

Maintaining the humidifiers (filters etc.) is a nuisance but has become second-nature and isn't an issue for me.

About summer: Not much of an issue. The humidity never gets terribly high (as per hygrometer) and in any event the dryness is what I'm most concerned about. (By the way, is the latter not proper?)

Thanks so much again!!!!

Cy wasn't talking about DC's being plumbed into a water line; he was talking about room humidifiers. DC's fill easily from a slender watering can (provided).

As for what piano stores do in summer, most have air conditioning, so that takes care of the humidity without need for dehumidifiers.

Yes -- I understood that he was talking about room humidifiers there, but thought that since he seemed to be making a contrast to the DC, he might have been implying that the DC is plumbed into the water line.
Thanks for clarifying!! (I don't blame him for not saying it differently, because he had no reason to think I was quote as ignorant about it as I am.)

It seems to me that this water-filling aspect isn't a significant additional advantage for the DC over 'regular' humidifiers; I don't see that the watering-can thing is materially different than what we have to do for regular humidifiers.
With the DC, you're carrying a watering can to the piano. With the other, you're carrying the tank to the sink. I suppose the former is a bit easier -- but I think not much.

@ MarkCannon

I believe there is a subtle and important difference between the room humidify and the Dampp Chaser system... at least in my case where I have a DC system installed in an upright. The DC controls the humidity inside the piano: at the moment as we enter autumn since it is getting colder outside - there has been a significant drop in humidity inside the house (in general low 40's % RH) even with the room humidity running - while inside the piano (with the DC) it has been in the high 50's with the heating bar (dehumidifier) running almost constantly. The upright piano is essentially a upright box and in my opinion probably more suited for a DC system than a grand (but I am willing to be corrected)... but if you are worried about strings rusting - hammers felts drying out - and the soundboard expanding due to excess humidity - for me the best place to control the humidity is inside the piano.

Since the volume of air inside the piano is much smaller that the volume of the room/house - of course the refilling of the DC occurs much less often ..

In the summer - we have no air conditioning so there are many open windows etc .. thus a dehumidifier makes no sense for us - far better that the humidity is kept low inside the piano.

I am not trying to convince you one way or the other - just giving the reasons that I use to justify the installation of the Dampp Chaser - of course if the external climate also has a controlled humidity - so much the better.

Thanks -- it seems like maybe the DC is even more important for an upright, which in a way is ironic because grands are usually more "precious" and so people might care more about taking the best care of them. You explain it well.

But, I wonder if the factor of "inside the piano" doesn't matter that much, because as long as the humidity in the area of the piano is kept within the proper range (including by regular humidifiers, or whatever), the entire inside of the piano will take on that same level of humidity.
I think.

Exactly what relative humidity is the DC system programmed to maintain? 50%?

There are choices, but the default is 42%. If a piano is accustomed already to a wetter or dryer climate, we can choose other humidistat settings.

Mark, the D-C needs less maintenance because it's humidifying a much smaller space. It does not connect to a water line; as I said earlier you typically add a gallon of water every 10 days.

--Cy--

I have a DC installed on my piano. I bought a $20 hygrometer at Radio Shack tonight, placed it underneath the piano about an inch or two from the soundboard--after about 20 minutes it's reading 57%. Is that acceptable?

EDIT: Now it's reading 60%

EDIT: Now 62% (maybe there's something wrong with the hygrometer )

Thank you -- and SORRY that I missed it before!!

I was worried about this same thing (the possibility of the the DC harming my piano) when I was considering buying one this past summer. Here's the thread on that:
http://www.pianoworld.com/forum/ubbthreads.php/topics/1254278/1.html

There are lots of other threads in the Tuner/Technicians forum on the Dampp-Chaser system, too.

(BTW, I did end up getting the DC system installed.)

.....AND???

I'm still trying to get past the haven't needed to tune my piano in 3 years. If my pianos aren't tuned within 9 monthes to a year I go nuts. I can't stand it when they're even a little out of tune? What, are the pianos never played? Someone please answer about the Damp Chaser, I'm interested to know the answer also.

And that's in New Mexico. In South Carolina I end up adding a gallon about once a month!

Actually, about two gallons a month is typical in winter across most of the US, especially the midwest and northeast with cold winters. Remember it's the *indoor* dryness that is being corrected, and that's caused by drying the air with your furnace.

They renamed the product the Piano Life Saver because many people were assuming wrongly that in dry climates there was no "dampp" to be chased. Our summers are dry in the high desert, and so many people use "swamp coolers" instead of refrigerated A/C. With these evaporative coolers, I've watched the indoor RH go from 30% in 60% in half an hour, while I'm just getting started on a tuning!

--Cy--

New ones are probably close enough (within 10%); they can drift over time as dust builds up. I'd have your tech check out your system.

Does it have a high/low memory? Let it sit overnight and see with the max and min are. What's the temperature?

--Cy--

Can a piano be damaged during installation??

If you touch the hydrometer, it will read high. I just purchased one from Lowes for less tha $10 that has a memory function, so you can see the historic highs and lows. I suggest mounting it on a wall or something, so you dont handle it when you take a reading.

Justin, there's a three-light panel about half the size of a deck of cards that attaches with two half-inch screws to the underside of the keybed, and some people worry about putting screws into their new piano. If they only new how many thousands of screws were already in it! I use tape for those people, but honestly, sometimes it's a lot messier to remove tape.

One of the reasons the system is only sold and installed by technicians is exactly to avoid any incidental damage. I prefer that owners not even try to clean inside a piano, just because you need to know your way around to avoid misaligning a damper or causing corrosion on a bass string by touching it.

The potential for damage is much higher through excessive humidity swings. I just tuned for a new customer this week, and I had to show her that her piano less than a year old had a hairline soundboard crack right down the middle.

--Cy--

Thanks very much Cy - that was pretty much my last question. Soundsw like a good investment.

I don't know if this helps those of you with concerns regarding the Dampp Chaser system but I recently saw a pamphlet for the system and in the back are endorsements from piano companies such as Kawai, Yamaha, Steinway etc. I can't imagine that any of these highly regarded companies would give their seal of approval if there was ANYTHING to be concerned about in installing one on your piano. But who knows, maybe I'm naive

And...
Had DC installed about two weeks after piano was delivered. First in-home tuning done about two weeks after that. Went through some high-humidity end-of-summer days and we're now heading into the dry days of winter. I'm filling the reservoir about every 2 weeks now, it seems. Haven't measured the humidity in the piano, but tuning seems to be holding well (not that my ear is that great; I'll see what my tech says next time he comes out. But because it's new, I expect it will be going out of tune). It is keeping me from worrying about the piano drying out or the soundboard cracking.

I think you're right.
I'm still hesitant.
But don't mind me.....see my sig:

Sounds like you're more than content with it and that there haven't been any evident issues.

Since you're a person who initially shared my fear, that's quite a vote of confidence.
Almost enough for me to think of shedding my paranoia.

AJF,

The endorsement by Steinway on the back of a DC marketing pamphlet is somewhat misleading. I've had several conversations with Steinway's people in charge of technical services as well as some of their techs and they unanimously caution against using the DC as a substitute for controlling humidity in the room.

They recommend the DC only if the room can not be adequately controlled.

fingers

Dam, now you've got us paranoid again!

But really, thanks very much for that. I'm trying to sort this all out, and I imagine others are too.

A New York DC seller/installer suggested that I monitor the RH over time before making any decisions. I'm on my 3rd grand and never used a DC. Maybe one of these days I'll give it a try.

fingers

Well ... they are going to say that - so if the soundboard warps or developes pressure ridges .. it is easy for any piano manufacturer to say the problem is that the humidity has not been properly controlled ... and therefore not their problem.
Certainly it the humidity of the room is controlled ... then the Dampp Chaser system is not needed.... however I suspect that in Europe - where air conditioning is not common; we have the situation in summer that dehumidifying the whole room (with open windows..) is not practical.... thus the DC system at least should help.

I have had my DC for about a month - the RH inside the piano varies between 53 and 57% ... while the room varies between 40 and 50%... I want to try to do the best thing for the piano - thus I have installed a DC.... maybe this is a waste of money - but at least I know that I am doing the best thing possible for the piano

If it's good enough for my magnificent 1937 Kurtzmann, it's good enough for a Steinway.

Yes, that was why I went with the DC -- because I have no way of controlling the room humidity (no AC, and open windows in the summer). Also, I have an upright, for which the DC is supposedly more effective (compared to in a grand).

The nice thing about having a dampp chaser on an upright is that the cabinet is so enclosed that the internal humidity can really be controlled. I had a dampp chaser on my upright (before I traded up to a grand) and I *really* noticed an improvement in tuning stability. The improvement is present with my grand but not to such a noticeable degree.

I install the fabric undercover on grands. It makes a big difference to help keep air flow isolated under the piano, and yet it's an open-weave fabric that breathes.

--Cy--

Cy, is it true that the tension resonator on a Mason & Hamlin makes the fabric undercover a bad idea?

Not in my experience. The undercover helps the air under the soundboard stay more constant than not. The constant cycling of the system keeps air moving. The undercover cloth has very large holes, like speaker cloth; it's very breathable.

--Cy--

From what I've read, the issue with the undercover on a Mason is more of an aesthetic problem than anything else. The tension resonator forces the undercover to have to hang lower I think.

Whole house humidifiers are powerful, not expensive, and can be run at the silent setting. Little noise. I use a Bemis humidifier, and it works pretty well. Yes, one has to treat the water and clean the unit often and replace the wick. However, the Dampp Chaser unit requires the same maintenance (changing wick, cleaning) in order to remain sanitary. That's the nature of humidifiers.

I also have a Soleus Dehumidifier that is extremely silent. It has only 280 watts, so it isn't a powerful beast, but it does the job. In the summer, we use central air anyway, as it gets to hot here in Southern Ohio, and that very effectively reduces the humidity at the same time.

While the D-C seems to be a great unit, there is nothing better than whole-room control. Not only your piano feels good in this case, but you, the player do, too. That's something the D-C cannot provide, obviously.

I have one concern about the D-C, though. The heating rod does not actually remove moisture from the air (as does a regular dehumidifier/airconditioner), but heats the ambient air to reduce relative humidity. If you use that feature in the summer in order to save on airconditioning cost, your house will already be pretty hot, and the heating rod will furthermore heat up the soundboard.
Say, your house is already at 80 deg. F and the RH is 70% inside after rain, then in order to get the RH down to 50%, the rod will heat the soundboard up to 90 deg F or even higher. In the fall this is no concern to me. But during the summer, I just don't feel comfortable with adding heat to soundboard wood. I'd rather remove moisture in the first place so that I don't have to heat the ambient air.

While the air may be heated by the rod, that does not necessarily mean that the soundboard comes to the same temperature. It has a lot of mass. I typically put no more than 100 watts of heating rods in a piano, so it's not a lot of heat. And recall that the system continuously cycles between wet and dry; heat doesn't build up.

I agree with you about whole-house control, as I've said before. The purpose of the system is to protect the small, critical environment of the piano when it is in harsh ambient conditions. My response to the many "what if" questions about the system is simply that it has has proved its success over many years in many pianos, including my own. And I'm picky!

--Cy--

Oh, you're right, depending on the size of the piano, and where you have to juggle the location of the water tank or tanks. Actually most pianos look better from underneath with the undercover, especially on stage, even if parts of it hang below the rim. The undercover is black.

A side benefit is if you have toddlers or pets, it keeps them from messing with anything from underneath, and possibly harming themselves or the piano.

--Cy--

I have lived in or near Toronto all my life and quite honestly the drastic swings in humidity and temperature will most certainly harm your piano over time. You won't see it happen as it is a slow death kind of like smoking cigarettes, and then its too late. Properly installed you would have no worries with a Dampp-Chaser and actaully it will extend the life of the piano in Toronto especially a drafty home with no A/C.