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Name: Frank
Status: Other
Grade: Other
Location: CO
Country: United States
Date: June 2006


Question:
Several people have told me that a freezer works much harder if it is in a very cold environment. That makes no sense to me. I am wondering if that is correct.



Replies:
Frank,

I suppose the confusing part of that explanation is understanding why a freezer should have to work harder when it is absorbing less heat from its environment. Not to worry, if it is freezing outside the freezer will not have to work at all.

On the other hand, the way most modern refrigerating units work is based off of evaporation. Simply put, when any substance makes the change from a liquid to a gaseous state, it must absorb a larger amount of energy from its environment. Evaporate this liquid in metal tubing with plenty of air flowing over them, and you will cool the air. Use a compressor on that gas, and Boyle's law takes over, raising the temperature of the gas tremendously. If the heat has somewhere to 'go', such as into air flowing over another set of coils, then the compressed (and now re-cooled) gas will condense back into liquid, ready to be pumped back through the system.

This whole system works fairly well, provided the outside temperature is in a range where the selected refrigerant can effectively bleed off its excess heat. If it is too hot, it is harder to shed that heat into the environment. If it is too cold, the refrigerant may become to cold to effectively take heat from the air it is supposed to be cooling.

Ryan Belscamper



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