> When I'm in residence the fridge is turned on 24 hours. In the
> warmer weather its duty cycle is about 40%. I'm thinking of
> putting an extra layer of insulation around it....

Br> You may already be doing this, but if not, take up a bunch of
Br> old plastic cordial bottles. Fill them with water and freeze
Br> them. Fill your freezer with as much stuff as you can. Then at
Br> night, take some of the bottles out and put them in the fridge.
Br> This will help the overall efficiency of both the fridge and
Br> the freezer ( assuming you have a freezer ). It will help a lot
Br> more than extra insulation.

 That's mad!

 A fridge is designed with two evaporators but one thermostat. The
fridge part is *controlled* by the thermostat at 4C and the freezer
follows hopefully at -18C. If you stuff the thermostat so it doesn't
work (put frozen water in there so it's super-cold), the machine will
not cycle and the FREEZER will get hot.

 A better fridge uses fan circulation with two thermostats, one of
which controls the fan feeding the fridge part, but the same principle
applies. The energy has to come from somewhere.

 Where do you think the energy that froze the water came from?

 I'll admit that a refrigerator *can* be more than 100% efficient (it
takes heat from the ambient) but in most cases they struggle to reach
100% in practice and what I say is true.

Regards,
Bob

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