yup. A fridge uses the radiator at the back of the equipment to
radiate heat away from inside the fridge. The heat transfer makes
the inside of the fridge cool, but using coolants evaporating at
much lesser than boiling point of water, normally coolants
evaporates around 5-10degC, that runs through tubes inside the
fridge to outside the fridge.
The heat that is taken off from inside the fridge by the
evaporated coolant, then cools down and precipitates back to liquid
to flow back. The outside hotter fluid is cooled by fans on the
radiators.
Thus when you open up the fridge, the room will not be cooled,
as the front side of the fridge gets cool, but the back side of the
fridge gets hot. In fact there is no change in overall temperature
of the room. For more advanced part, since there is no 100%
efficient systems, most probably, you will get a “hotter” room by
opening up the fridge door, as the regulator pumps up the needed
electricity to try to cool the whole room at higher temperature
than the chamber.
Same for aircon.
