Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

As we know fridge can't cool room in which it is (according to Second Law of Thermodynamics, heat emitted by fridge is greater than heat absorped).

However, when we go next to the fridge in supermarket we can feel coldness. Why?


share|improve this question
Well, you can feel it because you're on the cooled side, and the low temperature of course removes some heat from your body, too. This is increasingly strong if you actually open a fridge in the supermarket - or at home. You're right that the cooling devices have to heat something else up, but it's on a different side, and moreover, the whole supermarkets, and not just the fridges, usually have cooling systems that keep the whole area cooler than normal. Again, this is overcompensated by some heating outside the building etc. –  Luboš Motl Sep 28 '12 at 18:10
The difference is that a domestic fridge has the heat output on the coils at the back. While a commercial system in the supermarket will eject the heat outside eg a heat exchanger on the roof –  Martin Beckett Sep 29 '12 at 22:01

2 Answers 2

The cool air you feel near a supermarket fridge is due to imperfect insulation — or someone just opened the door :-)

Though it is true that a fridge can't cool a sealed room that it is completely in, just like air-conditioning, the heat is pumped via coolant to a radiator to be dissipated reasonably far away from the fridge so as to not heat up the surroundings of the fridge.

In other words, there is net heat loss in the vicinity of the fridge, but not in the whole universe!

share|improve this answer

Cooling Tower Australia

The idea here is like in cooling towers in Australia. But what makes the difference? Heat Exchangers.

share|improve this answer
It would be helpful if you explained your ideas instead of a brief post about one part (where the heat goes) of the answer. –  LDC3 May 30 '14 at 3:21

protected by Qmechanic May 30 '14 at 6:10

Thank you for your interest in this question. Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.