Create a hypothetical creature. It has the basic components of a refrigerator inside it. It uses this internal fridge to create liquid atmosphere which it can spray.

  • For condenser coils it has some sort of hard scute system on the outside of its body that is designed to increase surface area.
  • Refrigerant can be made internally or accrued from daily life.
  • The Condenser and Expansion valve would both be internal organs.
  • The Expansion coils would have a lot of surface area in it's internal fridge.

Generating "cold" in a living organism is notoriously unrealistic. Could this work?

  • $\begingroup$ Hi Robert, what liquid and how cold? Also what sort of volume of liquid are you thinking, how big is the creature? $\endgroup$ Jun 9 at 4:08
  • $\begingroup$ Hello Robert, welcome to Worldbuilding. Our job is to help you create and consistently use rules for a fictional world of your own creation. Consequently, it's unclear what your question is. Can you do what your asking? Sure! It's your world and you set the rules. Can you do it in Real Life? Of course not. Can you explain your concern or the reason why you're asking the question? Or do you have a specific question? ("Is this a good idea?" Qs are notoriously vague.) Please note for future reference, asking more than one Q is justification to close the Q (you're asking at least three). $\endgroup$
    – JBH
    Jun 9 at 4:19
  • $\begingroup$ Finally, please note that asking if the Leidenfrost Effect will be a problem is a bit odd since you're creating a fictional creature that doesn't obey the laws of physics or biology as we understand them. Note, too, that I've deleted the reality-check tag. You're not using it properly. It's purpose is to test an application against your rules, which means you need to provide all the rules and the test case. Please read the tag wikis before you use them. Thanks! $\endgroup$
    – JBH
    Jun 9 at 4:24
  • $\begingroup$ @JiminyCricket. I was thinking about 12 tons and liquid atmosphere so about 77 kelvin. Not sure how much I could make more concerned about it's possibility. $\endgroup$ Jun 9 at 5:24
  • $\begingroup$ @JBH Reality check was there because I needed to know if the creature would be viable assuming it was made in real life. I was trying to suggest ways the creature could fail using real world rules, because I want more from the answers than just "Can you do it in Real Life? Of course not." Please, if you know why it fails the reality-check, then give me that. $\endgroup$ Jun 9 at 5:59

1 Answer 1


Putting a fridge inside a creature is going to mess up the creature

There's nothing to really stop biology evolving a fridge. In many ways, the components are there - we've got pumps (circulatory system), radiators (consider desert dwelling animals, who have surfaces adapted for cooling), there's no cooling fluid, but prehaps an ethanol solution might work.

The problem is the chemistry. Generally, biochemistry of multi cellular organisms is adapted to quite a narrow temperature range. Most cold weather adaptions revolve around keeping the animals temperature up to a sensible level. Enzymes work slower under cold temperatures. Therefore, running your fridge will arguably slow down the functioning of your pump.

But! There's a better way!

Consider the bombardier beetle - it releases chemicals from two reservoirs that mix in a violent, heat producing reaction, that sprays boiling, corrosive chemicals over other insects

Swap out those chemicals for powerfully endothermic reactions - prehaps water and ammonium nitrate, and you have a freezing spray. Alternatively, you could have a high pressure gas reservoir, which releases nitrogen under pressure, making it cool as it does

Edit - The water and ammonium nitrate reaction might be possible to catalyse with a fictional enzyme, which would allow it to get to a colder temperature. This would be pretty plausible with other endothermic reactions too, I think.

  • $\begingroup$ First thanks for replying. I haven't yet found an endothermic reaction absorbs enough heat for my purposes. For the High pressure gas reservoir idea wouldn't I still need to cool it back down as pressurizing the gas would cause it to heat up? $\endgroup$ Jun 9 at 9:58
  • $\begingroup$ In regard to protecting rest of the body from the cooling effects. I do know some structural ways to protect the tissues from the refrigerant...in everything except the pumps. Yeah those needing to be on a flexible, low thermal conductivity, high strength yet oxygenated structure kinda screws me. Thanks I would not have caught that without you. $\endgroup$ Jun 9 at 10:12
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    $\begingroup$ I'd agree that the endothermic reaction would be tough - how cold are you looking for? Maybe something that evaporates super fast would work. I'm thinking that pressurizing a chamber would happen relatively slowly, with the creature able to redistribute or radiate the heat caused by the high pressure gas. So you'd end up with a reservoir of, say, body temperature nitrogen in a liquid state, which would cool rapidly on release. $\endgroup$
    – lupe
    Jun 9 at 10:14
  • $\begingroup$ and yeah, pumps are hard to protect from cold there -though I can conceive of a structure like the diaphragm, where you decouple the muscles from the thing doing the pumping, which would let you have your highly oxygenated, warm muscles without the heat $\endgroup$
    – lupe
    Jun 9 at 10:20
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    $\begingroup$ another random thought on this - my enzyme kinetics is only dimly remembered, but if you had an enzyme that catalysed the ammonium nitrate/water reaction, I think you'd get it to go colder - I think in the absence of a catalyst, it is self limiting because the colder it gets the less molecules can clear the activation energy threshold, and therefore fewer reactions occur. It'd still self limit with a catalyst, but maybe at considerably colder temperatures. Biology loves making catalysts for things, too :P $\endgroup$
    – lupe
    Jun 9 at 10:24

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