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Group - I know this particular email from Tom Strang concerns freezer trucks. He's right on with what I've been saying all along; you don't have to reach -20 F in 4 hours. Let me address chest-type freezers. There seems to be confusion out there about them. There are lots of chest-type freezers available today that can maintain -20 F. And frost-free freezers are OK. Do an on-line search and you'll see what I'm saying. Bed bugs and their eggs cannot withstand -20 F for 72 hours; not that bed bugs are a big deal in cultural collections anyway. Tom Parker -----Original Message----- From: Tom.Strang <tom.str...@pch.gc.ca> To: pestlist <pestlist@museumpests.net> Sent: Mon, Mar 12, 2012 2:37 pm Subject: Re: [pestlist] Freezer Trucks This is a message from the Museumpests List. o post to this list send it as an email to pestlist@museumpests.net o unsubscribe please look at the footer of this email. ---------------------------------------------------------- ear Dana, You should not be disappointed with your low temperature treatment. assume a record box is roughly 16 inches long, 12 inches wide and 10 nches high. Your email indicates they were stacked as walls. I assume they ere stacked sides-abutting to make them more stable leaving a wall 16 nches thick. With close packed organic, akin to bales of agricultural roduct, your stack will have a time to thermal half change in about one ay+. 72F degrees is 21C. -15 F is -26C, more than adequate to kill pest nsects so not achieving -20F (-28C) is not a concern as -20C is quite ufficient for a week. The fact you achieved -26C from 21C means you ropped 47C in 4 days, about a time to half change of a day (remember the rog jumping half down a log, then half again.. when does the frog jump off he log puzzle). Were you at 5F at two days? if so you were pretty much pot on what can be estimated from the chart I published in 1994, and is vailable in the CCI TB29 and on our website (find "ten agents pests"). old them at your -15F setpoint and you will have had an efficacious reatment unless there was thermal bridging from the bottom of the van into he base of the stack. If they were on pallets, and air circulated under, ll should be well. http://www.cci-icc.gc.ca/caringfor-prendresoindes/articles/10agents/chap06-eng.aspx Cheers, incerely, om Strang Canadian Conservation Institute | Institut canadien de conservation enior Conservation Scientist | Scientifique principal en conservation nstitut Canadien de Conservation | Canadian Conservation Institute ttawa, Ontario, Canada, K1A 0M5 tom.str...@pch.gc.ca éléphone | Telephone 613-998-3721 (extension 239) élécopieur | Facsimile 613-998-4721 éléimprimeur (sans frais) 1-888-997-3123 | Teletypewriter (toll-free) -888-997-3123 rom: dana senge <dkse...@gmail.com> o: pestlist@museumpests.net ate: 03/10/2012 08:50 PM ubject: [pestlist] Freezer Trucks ent by: ad...@museumpests.net This is a message from the Museumpests List. o post to this list send it as an email to pestlist@museumpests.net o unsubscribe please look at the footer of this email. ---------------------------------------------------------- e recently tried using a freezer truck to process a large number of oxes of archives. Record boxes were stacked in rows with 12" gaps etween the rows to allow for air circulation. We placed a datalogger n the center of one of the boxes of archive materials (in the center f the truck) and another outside the boxes to measure the temperature f 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 hours. Our data loggers showed that it took 10 hours for the air in he truck to go from 44 degrees F to -15 degrees F, and the emperature inside one of the record boxes took ~96 hours to drop from 0 degrees to -15 degrees. (The boxes had been in a 72 degree nvironment before being placed in the truck box). It appears that he starting temperature of the boxes of paper was more difficult to educe than I expected. And the truck never achieved the desired emperature. We are very disappointed in these initial results and are trying to igure out if there is a different strategy for using a freezer ruck, or if this is just not feasible for freezing densely packed aterials, such as paper packed in a record box. We are discussing acking boxes half full and packing the truck to allow for even more ir circulation. But it seems that getting to the goal of -20 degrees in 4 hours may not be feasible. Does anyone have any positive experiences working with a freezer truck or processing a large quantity of materials? Especially dense aterials such as wood or boxes of paper? hanks, Dana Senge ssistant Conservator ational Park Service ntermountain Region Museum Services Program ucson, AZ 85745 20-791-6432 ana_se...@nps.gov --------------------------------------------------------------------- o 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 n the subject put: unsubscribe" - no quotes please. You are receiving the Pestlist emails in standard mode. o change to the DIGEST mode send an mail to imail...@museumpests.net with this command in the body: set mode digest pestlist Any problems email l...@collectionpests.com or l...@zaks.com ---------------------------------------------------------------------- o 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 he subject put: unsubscribe" - no quotes please. You are receiving the Pestlist emails in standard mode. o change to the DIGEST mode send an mail 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
