Your description of rust-colored spots brings me to another question - do you have a fire suppression system in your ceiling? What kind is it? In my experience, dry pipe systems will sometimes drip bits of greasy brownish sludge at the joints. If the system is older than about five years, you might want to have someone with a borehole camera take a look at the condition of your pipes. Good luck, whatever the cause of your woes. Anne Lane Collections Manager Mountain Heritage Center Western Carolina University 828-227-7129 On Aug 25, 2015, at 12:10 PM, charlene martin <[log in to unmask]> wrote: > Thank you for the reply - I have definitely added more info, so please reply with further advice! > > My archive storage rm is located in Syracuse NY, within a mixed use office floor. Is 65 degrees is too cold for the summer? What is the ideal seasonal drift rate for summer in Syracuse NY, for both temp and RH? > > We just moved in 2 wks ago. I designed the archival storage room as a preservation space, but have found some specifications were compromised. As a result, I have a suspended (drop) ceiling made of tiles of some corrugated-type material, set on a grid. > > The moisture is showing up in the form of rust-colored spots on the tile (please see pic).I do not have a schematic of the ductwork in the ceiling (am working on getting that from the facilities manager), but I suspect that pipes are indeed "sweating". > > > > > On Tue, Aug 25, 2015 at 11:25 AM, Marc A Williams <[log in to unmask]> wrote: > Where is your facility/museum located (town, state)? That may make a difference in the recommendation. 65 degrees is really cold for the summer. Depending upon your specific situation and lay-out of HVAC equipment & duct work, I would guess that you are getting condensation on the ductwork, which is causing the ceiling to be wet from dripping above it. This is relatively common, but is not always noticed. Do the ducts run near the spots? What type of ceiling do you have - plaster, drywall, suspended, something else? How does the moisture show up - damp spots, water dripping, mold growing, something else? The more info you can present, the better the answer. Of course, nothing beats in-person observation. > > Marc > > American Conservation Consortium, Ltd. > 4 Rockville Road > Broad Brook, CT 06016 > www.conservator.com > 860-386-6058 > > *Collections Preservation Consultation > *Conservation Assessments & Surveys > *Environmental Monitoring & Low-Tech Control > *Moisture Management Solutions > *Collections in Historic Structures > *Collections Care Grant Preparation > *Conservation Treatment of: > Furniture > Painted Wood > Horse-Drawn Vehicles > Architectural Interiors > Decorative Objects & Folk Art > > Marc A. Williams, President > MS in Art Conservation, Winterthur Museum Program > Former Chief Wooden Objects Conservator, Smithsonian Institution > Fellow, American Institute for Conservation (AIC) > > > > From: charlene martin > Sent: Tuesday, August 25, 2015 10:58 AM > To: [log in to unmask] > Subject: [MUSEUM-L] HVAC settings for mixed collection storage rooms > > Hi everyone - > > I have one storage room for housing textiles, paper documents, books, and mixed-medium artwork. > > I have set my HVAC for 65 degrees with a 5 degree season shift, and he relative humidity for 50% with a 5 percent seasonal drift. > > Is this good for a mixed collection storage room? Has anyone heard of this causing moisture to be gathering in spots on the ceiling? > > Thank you! > > To unsubscribe from the MUSEUM-L list, click the following link: > http://home.ease.lsoft.com/scripts/wa-HOME.exe?SUBED1=MUSEUM-L&A=1 > > > To unsubscribe from the MUSEUM-L list, click the following link: > http://home.ease.lsoft.com/scripts/wa-HOME.exe?SUBED1=MUSEUM-L&A=1 > > > > To unsubscribe from the MUSEUM-L list, click the following link: > http://home.ease.lsoft.com/scripts/wa-HOME.exe?SUBED1=MUSEUM-L&A=1 > ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).