In which I record the temperature of my fridge and surrounding
environment, and track events that take place involving the fridge,
in order to answer the question, "Can I unplug my fridge at night
without ruining my food?".
It turns out turning off your fridge
is for it. Details here.
back of fridge,
Download the data: top,
- All events involving temperature changes in the home are
recorded. Click on the vertical gray bars to get detailed
information about each event.
- The first 24 hours are a the baseline.
- During the night of the 14/15th, I unplugged the fridge from
2300 to 0800, and the temperature rose from the baseline to 9 and
10 C for the back and door, respectively. The freezer rose from
-20 C baseline to -4 C.
- During the 2nd day (April 15), I added a bunch of liquid to
increase the thermal capacity. The addition is visible by the
spike at 1845 and the note at that time. Unfortunately, the
liquid was added too late in the evening, it did not cool, and
it therefore acted as a heater during the night. The temperature
rose to 9 and 11 C for the back and door.
- For the remaining time, April 16, 17, and 18, I did not
unplug the fridge. The temperature variation is
slightly less, especially near the front of the fridge (green
line, door), due to the added liquids.
- This is part 2 of the above experiment.
- Different dates, no events recorded. Only recorded
temperature for fridge door
and back of fridge.
- The first two nights have roughly the same liquid that
was added on Fri, 15 Apr 2011 18:45:00 GMT (see above graph). This
liquid acted as a heater the first night.
- Here it has equilibriated with the fridge temperatures, and
the maximum temperatures at 0800 after unplugging the previous
night at 2300 are 8 and 10 C, rather than 9 and 10 C.
- A small amount of additional liquid was added the afternoon
of the 20th, and the temperatures drop by 1 C to 7 and 9 C for the
last two days.
Conclusion: With enough water (or steel blocks) acting as a thermal
mass, it is safe to unplug the fridge at night. Meat or fish should be
consumed quicker than if the fridge stayed plugged in. Any meat or fish
should stay in the fridge for 1 night maximum.
- The mean normal value in the door is 5.0 C and at the back is 2.6 C.
- Calculating the area under the last curve, less the mean
temperature, there is a positive thermal anomaly of 25 degree-hours
for the door and 28 degree-hours for the back of the fridge.
(1 degree above normal for 1 hour is 1 degree-hour.)
- We note that food decay is non-linear, so degree-hour is not
the best unit to explain the additional heat. For example, 1 hour at
10 degree will spoil food faster than 10 hours at 1 degree, but both
compute to 10 degree-hours.