On Jun 23, 2009, at 12:16 PM, Jeff Stickney wrote: > If this is a gray market Yamaha, I have a customer who purchased one > and had it shipped to dry Montana. The cracks didn't appear > instantly, but they are definitely there now. He also has radiant > floor heat. Anyone have any idea if that heat source has a drying/ > heating effect on pianos - more than forced air or steam sources? I > know it warms cabinets, furniture, etc. noticeably. > > Jeff Stickney > Hi Jeff, I think radiant heating can be a real problem, and can exacerbate humidity issues by drying a piano more than the ambient RH would do. I think that what happens is that through conduction, heat is moved into the body of the piano. That heat then vaporizes the water within the wood. In order to warm the air temperature to a target temperature, the floor has to be a few degrees warmer, hence the piano would also become warmer than the surrounding air (at least as I imagine what is happening). I think the same thing can happen (but with different physical movement of heat) when there are radiant floorboard heaters (essentially long, low radiators along the outside walls of a room) near a piano. In this case, the heat enters the piano through convection and radiation, and, again, the piano can potentially become hotter than the air in the room. In any case, in my experience with a few customers with these setups for heating, I have installed full humidity control systems, and I have found that the system can't seem to overcome that winter heat, that the pitch change is far worse than with other customers with similar pianos, even in conditions where there is a forced air source near a piano. I have been looking at ways to shield the piano - but not be too unsightly in the process. Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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