What is an Ultra low temperature freezer?


ULT Freezer

Ultra low temperature freezers are often known as ULT or minus 80 freezers. Quite simply because that is how cold they get. Eighty degrees Celsius below zero. This temperature is required to keep most biological samples for more than a few weeks. At this temperature of minus 80, they will store well for a few years and Carbon dioxide (CO2) will be solid!

ULT freezers have much better insulation than your typical home freezer. Instead of cheap expanded polystyrene foam loosely held in the wall, a good ULT freezer will utilise a quality micro-pore foam sandwiched in a vacuum between two sealed panels. Like so:


Unlike your home freezers, ULTs usually employ two compressors cascaded so that one cools the other. Like this:



Here the evaporator on the right is inside the ULT keeping the pies frozen and the evaporator in the middle cools the HFC refrigerant.


ULT freezers usually have several doors. The outer door or two being the main insulated door, perhaps with a lock mechanism and a control panel incorporated. Open this and you will see up to four inner doors. This is so that only one quarter of your samples will be exposed to the warm ambient air while you fossick around looking for your sample.

You can download a brochure showing the whole range of Haier minus80 freezers here.

Contact CCAT:

        Free phone 0800 222 812 (0800 CCAT12)

       email: info@ccat.co.nz

Australia free phone 1300 978 820 or email: adrian@brightsidescientific.com.au      

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