Hi Don, > I did not say your system didn't work. What I said was a DC system would > work even better. Perhaps. Perhaps not. I don't mean to be argumentative on this point. I'm really asking a question here: Have you (or has anyone else) done measurements with a good, accurate hygrometer on a complete DC grand installation, during dry ambient conditions, showing that humidity is indeed evenly distributed all over the soundboard, both under and on top, and in the action cavity? Also, have the same measurements been done inside the piano with a closed lid and inside the action cavity during predominantly dehumidifying periods? In other words, are DC's claims fully substantiated, as determined empirically with a hygrometer? I've heard lots of claims regarding stability of pitch. That's all well and good, of course. However, how well does the DC system regulate humidity (in contrast to pitch)? > I do recommend room type humdifiers as well--but only to "assist" a DC > unit. If it is a choice of one or the other the DC provides much better > year round control than is generally possible with a room type. There are > exceptions, but they are very rare. This sounds like a reasonable approach. > Do you have measurements for the summer time? Where I am I have documented > as low as 4% and as high as 84%. Without humidification, humidity levels inside my house vary from 27% in the winter to 67% in the late fall. I have forced heat and refrigerated A/C, BTW. I suspect humidity levels are far different in other parts of the state. I'm in Central Ohio. In the lake areas, humidity is undoubtedly much higher during moderate weather. Also, I have no idea what humidity levels occur in other people's homes here in Columbus. (I don't service their pianos. <grin>) > I would love to have a controller for a DC type system that had much > narrower limits. I know, for example, that rare bird hatcheries have units > that are calibrated to 1/10 of one percent humidity that power an > "electronic" fan (read no blades--some sort of vibrating plate) combined > with an ultrasonic humidifer. I'd love to get my pinkies on one! Well, I can't boast 0.1% limits with my system (WOW!!), but I do quite a bit better than the specs DC boasts. I did a 100% non-DC-brand installation on my concert grand, using a GE humidistat that cycles the system adjustably between 40 - 44% (or occasionally as widely as 39 - 45%) when the ambient RH is in the upper 40's. The installation is fairly recent, so I haven't yet been able to observe its behavior at higher humidity levels. I'll give you an update in the spring if you're interested. Peace, Sarah
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