"Rod Speed" wrote in message
...
NY wrote
Maurice wrote

When the temperature is lower than this, the fridge freezer will use
more energy to maintain the right temperature.

How can it take *more* energy to run a freezer if the ambient temperature
is lower and therefore there is less heat transfer from the room to the
freezer that the compressor needs to remove.

When the refrigerant doesnt work as well at that temp.

In terms of the amount of heat that can be carried away from the freezer
chamber per unit amount of refrigerant?

Given that the refrigerant needs to boil to extract heat by latent heat of
vaporisation, it won't work if the ambient temp is below the refrigerant's
boiling point...

Seems counter-intuitive.

Sure.

But then it always seems counter-intuitive that a vacuum cleaner uses
less power (and the motor runs faster) when the outlet is blocked by your
hand and the hoover is sucking hardest. I can see why this is (lack of
airflow), so maybe there's a similar reason why a freezer in a cold room
(more similar to the temp inside the freezer) uses more power.

Yes, because the refrigerant behaves differently.

Ah. OK. Yes, I understand that. Thanks. I wasn't sure whether it was
manufacturers' bull**** but it sounds as if there are reasons of physics
behind it, which I believe far more readily :-)