<br><br> <div class="gmail_quote">On Feb 8, 2008 4:29 PM, Jeff Tanner <<a href="mailto:jtanner@mozart.sc.edu">jtanner@mozart.sc.edu</a>> wrote:<br> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"> <div style="WORD-WRAP: break-word">Hi all, <div>We've had a humidity "spike" in our recital hall the last week or 10 days.  Every one is screaming that the keys are clammy, fiddle fingerboards are clammy and bowhair "skids rather than grabbing the strings".  Yeah, yeah, yeah, the pitch of the piano jumped a few cents over last weekend, but nothing is screaming high humidity to me.</div> <div><br></div> <div>The "spike"?  We were up to a whopping 55% at one point, which by August standards would be a kiln.  But we'd been running in the upper 30% to low 40% range fairly consistently until this "spike".</div> <div><br></div> <div>Question is, why is it faculty and students seem to notice condensation on the keys if it gets over 48% in February, but if it's 75% in a studio in July, nobody mentions it?</div> <div><br></div> <div>I understand walking out of a much cooler, drier hallway into the recital hall, which has humidification/dehumidification that is actually working, there is a noticeable difference in the feel of the air.  But why is there a difference in condensation, or why is there a perception of clamminess now and not in August?</div> <div><br></div> <div>Thanks,</div> <div>Jeff</div><font color="#888888"><br><br> <div><span style="WORD-SPACING: 0px; FONT: 12px Helvetica; TEXT-TRANSFORM: none; COLOR: rgb(0,0,0); TEXT-INDENT: 0px; WHITE-SPACE: normal; LETTER-SPACING: normal; BORDER-COLLAPSE: separate; border-spacing: 0px 0px"> <div>Jeff Tanner, RPT</div> <div>University of South Carolina</div> <div><br></div><br></span></div><br></font></div></blockquote></div> <div><br>Hi Jeff,</div> <div> </div> <div>Leave it to us northern boys to explain. It's the combination of the humidity and the cool winter air that causes the condensation, the heat isn't running enough to dry it out so as the room cools with a higher humidity content the RH condenses on the non-porous surfaces making them feel clammy. If it sustains for a long enough period you will begin to notice a fresh coat of rust on tuning pins and strings from same.</div> <div>In this area we have two types of AC in summer, the standard type that de-humidifies as it cools and the large commercial types in big buildings called chilled water type that (simplified) uses a  fan blowing across pipes that have cool ground water pumped through them. It cools the air but doesn't dehumidify and it feels "colder" when you walk in because it is cold "wet" air. The hard surfaces feel clammy in those buildings too. Same principle different time of year.</div> <div><g> <br clear="all">Mike<br>-- <br>We have enough youth, how about a fountain of SMART?<br>Michael Magness<br>Magness Piano Service<br>608-786-4404<br><a href="http://www.IFixPianos.com">www.IFixPianos.com</a><br> email <a href="mailto:mike@ifixpianos.com">mike@ifixpianos.com</a> </div>