Elwood, I would suggest that keeping museum level humidity control is very expensive, and is not likely to be achieved. There is something to be said for giving very tight specs at the start then allowing them to relax them a little when the building is finished, though. I like that approach - but it also could cause your input to be dismissed as too extreme. I would suggest that your 25% low number could be the result of a not so accurate humidity gauge. This is a common low limit for many electronic gauges, so if that is what you are using, try a better one, or a sling psychrometer. I've found it is extremely common in any variable climate for inside humidity to drop to the single digits in the winter. 48%-50% will certainly make the pianos nice and stable. 45% - 55% will also be nice, and is more reasonable for the designers. 35% - 65% is an achievable maximum tolerance in most locations that also contributes to the piano tuner's job security. Beyond that there be dragons. The most serious issue at many institutions is the fresh air requirement in schools. There is a requirement that the air in a school building be exchange completely over some period of time (which I think varies by state), so the HVAC systems sometimes just dump a bunch of outside air into the system periodically, and the system then works to dry it or humidify it. This kind of thing can be a nightmare for concert tunings, and is very bad in general for most of the musical instruments. I was visiting a school once where someone was demonstrating the pipe organ to me when the cold outside air got dumped into the building - wow, you should have hear the results! It took about 15 minutes for it to settle back down, and the wood pipes, I'm sure, were not happy about the process. I know it is possible for the system to be set up to treat the air as it is being brought in from outside, but the HVAC designers often do not take this into consideration. I would make this a priority in your discussions with the architects. I was impressed with the music building at the University of Manitoba in Winnipeg. They put up with serious weeping window / wall problems in the winter, and are able to keep the humidity in the building at 35% minimum through the crazy cold and dry winters in that city. I was there when it was -5 F outside last year, and the building was cozy at about 68 degrees and 35% humidity, but the windows were all wet, and the plaster and paint below the windows peels and looks bad. The humidity in my hotel room was 7%. I got it up to 25% after a good hot shower. I'll be interested to hear from others if any of the newer buildings on the CAUT list are able to maintain good tight temp / humidity ranges. Don Mannino _____ From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Elwood Doss Sent: Wednesday, May 13, 2009 9:29 AM To: caut at ptg.org Subject: [CAUT] Ideal humidity levels Just to confirm this with some other CAUTs. The ideal humidity level for pianos is between 48% and 52%. My Interim Chair shared that information with the architects and they said, "Wow, those are some tight parameters." We are planning to press for those parameters. Just wanted to get some thoughts from some of you who have gone through a renovation/construction experience at your schools. Is it a possibility? Very expensive to do that? How far from ideal can we go and keep the pianos in a comfortable environment. I've measured the humidity level in the present Fine Arts Building as low as 25% in winter and 80% in the summer with the air conditioning on. Joy! Elwood Rev. Elwood Doss, Jr., M. M. E., RPT Piano Technician/Technical Director Department of Music 145 Fine Arts Building University of Tennessee at Martin Martin, TN 38237 Office: 731/881-1852 Fax: 731/881-7415 Cell: 731/479-4043 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20090513/4e98711f/attachment.htm>
This PTG archive page provided courtesy of Moy Piano Service, LLC