<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> Jim, I am very much enjoying your contributions on this topic.  The matter of popular perception/received wisdom versus published evidence base (or lack thereof) is always interesting.  Thank you for sharing your experience with your own Chickering. To be factored into the discussion is whether electric infloor heating may affect uprights differently from grands.  In a grand the soundboard and plate are obviously parallel with the floor, and at a distance of over 30" from the floor.  Presumably the soundboard and plate get evenly heated.  With the  upright piano the soundboard, plate (as much plate as there is in my particular case, an old English overdamper)  obviously graduates in distance from the heat source, the floor. Going, I suppose, from casters in contact with the heat source, through the bottom edge of the soundboard perhaps 4" from the floor, to the top edge, maybe about 40" from the floor. I have emailed the owner to ask if he knows anything about the heat differential between floor level and key height.  Overall, I feel fairly sanguine that the electric infloor heating will not damage the piano.  Thanks again to everyone for this interesting discussion! Best regards, David. . <div class="moz-cite-prefix">On 13/12/2012 15:08, <a class="moz-txt-link-abbreviated" href="mailto:pianotech-request@ptg.org">pianotech-request@ptg.org</a> wrote: </div> <blockquote cite="mid:mailman.4402.1355411300.4133.pianotech@ptg.org" type="cite">I find a striking disconnect between technician reports on the aggressiveness of infloor heat regarding piano seasonal stability and piano soundboard/pinlock health, and both the technical research and on site installed experience gathered by the heating industry professionals and researchers on these systems. Over the last 20 yrs the in-floor systems have exhibited significant advantages over traditional systems.  In-floor systems have proven to be more comfortable, gentle, and allergen friendly than any of the traditional heating options, providing even temperatures, much less vertical temp striation, and allowing the occupied spaces to be kept at lower temperatures(thus easier to maintain higher RH) than their convective/forced counterparts. <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://legalett.ca/Radiant_Floor_Heating_in_Theory_and_Practice.pdf">http://legalett.ca/Radiant_Floor_Heating_in_Theory_and_Practice.pdf</a> .................................... In the spirit of taking the information where it takes us, I'll start, with my own experience. My own grand, Chickering122, 5' grand, my own new re-manufacture (new rib crowned board, block, the works), full DC, floor length cover always covering instrument when I'm not playing, in my living room with in-floor heat. </blockquote> </body> </html>