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Dear Dana, You should not be disappointed with your low temperature treatment. I assume a record box is roughly 16 inches long, 12 inches wide and 10 inches high. Your email indicates they were stacked as walls. I assume they were stacked sides-abutting to make them more stable leaving a wall 16 inches thick. With close packed organic, akin to bales of agricultural product, your stack will have a time to thermal half change in about one day+. 72F degrees is 21C. -15 F is -26C, more than adequate to kill pest insects so not achieving -20F (-28C) is not a concern as -20C is quite sufficient for a week. The fact you achieved -26C from 21C means you dropped 47C in 4 days, about a time to half change of a day (remember the frog jumping half down a log, then half again.. when does the frog jump off the log puzzle). Were you at 5F at two days? if so you were pretty much spot on what can be estimated from the chart I published in 1994, and is available in the CCI TB29 and on our website (find "ten agents pests"). Hold them at your -15F setpoint and you will have had an efficacious treatment unless there was thermal bridging from the bottom of the van into the base of the stack. If they were on pallets, and air circulated under, all should be well. http://www.cci-icc.gc.ca/caringfor-prendresoindes/articles/10agents/chap06-eng.aspx Cheers, Sincerely, Tom Strang Canadian Conservation Institute | Institut canadien de conservation Senior Conservation Scientist | Scientifique principal en conservation Institut Canadien de Conservation | Canadian Conservation Institute Ottawa, Ontario, Canada, K1A 0M5 tom.str...@pch.gc.ca Téléphone | Telephone 613-998-3721 (extension 239) Télécopieur | Facsimile 613-998-4721 Téléimprimeur (sans frais) 1-888-997-3123 | Teletypewriter (toll-free) 1-888-997-3123 From: dana senge <dkse...@gmail.com> To: pestlist@museumpests.net Date: 03/10/2012 08:50 PM Subject: [pestlist] Freezer Trucks Sent by: ad...@museumpests.net This is a message from the Museumpests List. To post to this list send it as an email to pestlist@museumpests.net To unsubscribe please look at the footer of this email. ----------------------------------------------------------- We recently tried using a freezer truck to process a large number of boxes of archives. Record boxes were stacked in rows with 12" gaps between the rows to allow for air circulation. We placed a datalogger in the center of one of the boxes of archive materials (in the center of the truck) and another outside the boxes to measure the temperature of the air in the truck box. The results were surprising. We had been informed that the truck would go down to -20 degrees F in 4 hours. Our data loggers showed that it took 10 hours for the air in the truck to go from 44 degrees F to -15 degrees F, and the temperature inside one of the record boxes took ~96 hours to drop from 70 degrees to -15 degrees. (The boxes had been in a 72 degree environment before being placed in the truck box). It appears that the starting temperature of the boxes of paper was more difficult to reduce than I expected. And the truck never achieved the desired temperature. We are very disappointed in these initial results and are trying to figure out if there is a different strategy for using a freezer truck, or if this is just not feasible for freezing densely packed materials, such as paper packed in a record box. We are discussing packing boxes half full and packing the truck to allow for even more air circulation. But it seems that getting to the goal of -20 degrees F in 4 hours may not be feasible. Does anyone have any positive experiences working with a freezer truck for processing a large quantity of materials? Especially dense materials such as wood or boxes of paper? Thanks, Dana Senge Assistant Conservator National Park Service Intermountain Region Museum Services Program Tucson, AZ 85745 520-791-6432 dana_se...@nps.gov ---------------------------------------------------------------------- To send an email to the list, send your msg to pestlist@museumpests.Net To unsubscribe from this list send an email to pestlist@museumpests.net and in the subject put: "unsubscribe" - no quotes please. You are receiving the Pestlist emails in standard mode. To change to the DIGEST mode send an email to imail...@museumpests.net with this command in the body: set mode digest pestlist Any problems email l...@collectionpests.com or l...@zaks.com ---------------------------------------------------------------------- To send an email to the list, send your msg to pestlist@museumpests.Net To unsubscribe from this list send an email to pestlist@museumpests.net and in the subject put: "unsubscribe" - no quotes please. You are receiving the Pestlist emails in standard mode. To change to the DIGEST mode send an email to imail...@museumpests.net with this command in the body: set mode digest pestlist Any problems email l...@collectionpests.com or l...@zaks.com
