Common home freezers usually have the lowest temperatures of about -24 degrees Celsius. Freezers that go lower exist but these are much more expensive (times much). I wonder whether a common kitchen freezer (standalone without fridge) could be easily hacked to achieve lower temperatures than those -24C (like -40 or -60/-80).

I guess the task is either to hack the thermostat for lower temperature or to disable the termostat at all and supply custom thermo-regulation-circuitry (attach thermometer and then switch the whole freezer on/off as needed to regulate the temperature).

Any ideas how to do this? I guess the structure of the freezer should probably be able to withstand a bit lower temperatures that what it is designed for.

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    $\begingroup$ Start by studying the refrigeration cycle and the constraints that the choice of refrigerant imposes on the achievable temperatures. $\endgroup$
    – Transistor
    Mar 22, 2021 at 21:56
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    $\begingroup$ The "hack" is easy: find the thermistor or thermocouple in the freezer and reroute it so it's outside the frig. The cooling system will continue to attempt to reduce the temperature without stopping; that will tell you how cold the existing compressor, refrigerant, etc. can make your freezer. $\endgroup$ Mar 23, 2021 at 11:47
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    $\begingroup$ you might start freezing in other parts of the fridge, overpowering defrosters, blocking drainage lines etc $\endgroup$
    – Pete W
    Mar 23, 2021 at 13:07
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    $\begingroup$ IF it's just for short term, do what I did and get 10kg of dry ice from a Dairy (crushed or solid bricks) and use a well-insulated plastic picnic box -45 'C. $\endgroup$ Mar 24, 2021 at 2:42

1 Answer 1


No. The minimum temperature is set by the characteristics of the refrigerant. You could conceivably use a refrigerant with the characteristics you want, governed by a new thermostat setting, but I suspect that it will require a redesign of the refrigeration system.

  • $\begingroup$ You should edit to say "the minimum temperature is limited by ..." $\endgroup$ Mar 24, 2021 at 12:44

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