Hi Julia, We have two So-Low model CH40-25 freezers, one purchased in 2024 and another purchased earlier this year. We've been pretty happy with them, as the size accommodates a variety of box sizes and the rep was easy to work with. About mid-way deep, we maintain about -32 to -34 deg C when set at the -40 deg C setting. I would be happy to put you in touch with the conservator who sourced them and has been the main user if you have any specific questions!
Best, Sarah On Thu, Oct 9, 2025 at 6:36 PM 'Cynthia Kapteyn' via MuseumPests < [email protected]> wrote: > Hi Julia, > > We use the So-Low chest freezer model C40-21. > We got this one because it has the motor on the bottom and not the side, > so the interior depth is the widest we could find. Additionally, it does > not have the step on the inside that some chest freezers have. This was > important to maximize the space especially for rolled textiles. We have > also frozen bankers boxes of documents in it. > > It does require manual defrost every 6 months to a year. > > Here are the specs and diagram from their website: > C40-21.pdf > <https://www.so-low.com/content/data/product/spec_sheets/C40-21.pdf> > C40-21 <https://www.so-low.com/content/data/product/diagram/_C40-21.pdf> > > Feel free to email me directly if you have any more questions. > > Best, > Cynthia > > > *Cynthia Kapteyn* > Book and Paper Conservator, Digitization Coordinator > The Huntington > T: 626-544-0338 | E: [email protected] > 1151 Oxford Rd, San Marino, CA 91108 > [image: The Huntington Logo.png] <https://www.huntington.org/> > > ------------------------------ > *From:* [email protected] <[email protected]> on behalf > of Julia Sybalsky <[email protected]> > *Sent:* Thursday, October 9, 2025 13:43 > *To:* [email protected] <[email protected]> > *Subject:* [PestList] Ultracold Chest Freezers > > You don't often get email from [email protected]. *Learn why this is > important <https://aka.ms/LearnAboutSenderIdentification>* > > Hello Pest-listers – > > Does anyone have a -40 ultracold chest freezer purchased in the last 5 > years that they like and could provide a spec for? Or if not a specific > model, a manufacturer that you have found reliable over that or a longer > period of time? We have a walk-in freezer that we have used for many years; > this will be a supplemental unit. > > > > A couple specific models are mentioned in older posts, but I haven’t found > recommendations from firsthand experience: > > - *SO-LOW CHEST STYLE FREEZER TO -40ºC* *MODEL CH40-22* > > *https://www.so-low.com/content/data/product/spec_sheets/CH40-22.pdf > <https://www.so-low.com/content/data/product/spec_sheets/CH40-22.pdf>* > > - Thermo Fisher Scientific *Revco™ CxF Series -40°C Ultra-Low > Temperature Chest Freezer* > > *https://www.thermofisher.com/order/catalog/product/ULT2050-10-A > <https://www.thermofisher.com/order/catalog/product/ULT2050-10-A>* > > > > Thanks very much! > > > > > > [image: signature_2829500402] > > *Julia Sybalsky* > > Conservator > > Science Conservation Department > > American Museum of Natural History > > 200 Central Park West > New York, NY 10024-5192 > > *e:* *[email protected] <[email protected]>* > *m:* 413-695-9844 | *w:* 212-313-7533 > > > -- > To unsubscribe from this group, send email to > [email protected] > View this message at > *https://groups.google.com/a/googlegroups.com/d/msg/pestlist/topic-id/message-id > <https://groups.google.com/a/googlegroups.com/d/msg/pestlist/topic-id/message-id>* > --- > You received this message because you are subscribed to the Google Groups > "MuseumPests" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to *[email protected] > <[email protected]>*. > To view this discussion visit > *https://groups.google.com/d/msgid/pestlist/BL0PR14MB3602BB99E5FB8EFF7E4C97C9CAEEA%40BL0PR14MB3602.namprd14.prod.outlook.com > <https://groups.google.com/d/msgid/pestlist/BL0PR14MB3602BB99E5FB8EFF7E4C97C9CAEEA%40BL0PR14MB3602.namprd14.prod.outlook.com?utm_medium=email&utm_source=footer>* > . > > -- > To unsubscribe from this group, send email to > [email protected] > View this message at > https://groups.google.com/a/googlegroups.com/d/msg/pestlist/topic-id/message-id > --- > You received this message because you are subscribed to the Google Groups > "MuseumPests" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/pestlist/SJ0PR10MB45755DE9BF0F7B656604BD79A3EEA%40SJ0PR10MB4575.namprd10.prod.outlook.com > <https://groups.google.com/d/msgid/pestlist/SJ0PR10MB45755DE9BF0F7B656604BD79A3EEA%40SJ0PR10MB4575.namprd10.prod.outlook.com?utm_medium=email&utm_source=footer> > . > -- *Sarah A. Gordon* Preventive Conservation Technician Conservation and Science The Art Institute of Chicago | artic.edu (312) 443-3302 Pronouns: she/her/hers -- <https://www.artic.edu/> *Strange Realities: The Symbolist Imagination <https://www.artic.edu/exhibitions/10094/strange-realities-the-symbolist-imagination>* Through January 5 _*Hours and visiting policies <https://www.artic.edu/visit>*_ -- To unsubscribe from this group, send email to [email protected] View this message at https://groups.google.com/a/googlegroups.com/d/msg/pestlist/topic-id/message-id --- You received this message because you are subscribed to the Google Groups "MuseumPests" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/pestlist/CAM68RVEgTBS-DbgdcA4hJ6LZDxx-eHBH0FGhwvw50sZ4hQ%3DBbw%40mail.gmail.com.
