Ryk wrote in
:

The exterior of a typical little bar fridge is a heat dissipation
surface, so insulating it from the surroundings would be a bad idea.

Ryk




You are correct for the new ones.

I was cruising on of my thrift shops today and paid $10 for a Sears
Kenmore 2.2 cu ft little bar fridge in nice condition. "I don't think
it runs.", the check out guy said. "The compressor doesn't run."

Well, always skeptical, I plugged it into one of the test outlets on the
shelf and fired it up. The evaporator froze my skin to the aluminum
evaporator in about 3 minutes from a dead start. I turned it around
because I couldn't hear it running, either! The little compressor is SO
quiet you can't even hear it start!

Looking at the various labels I saw it was running R-12, which would
account for its quiet operation at such low pressure. Then, I spotted
the CURRENT DRAIN at 120VAC of .6A! Hmm...72 watts running = 5.2A at
13.8V on charged house batteries through a little high efficiency
inverter...exactly what's on the thousand dollar marine fridges.
Getting it home, I confirmed 71 watts under full head pressure and the
hole external condensor sticking out the back of it....NOT HEATING THE
DAMNED CASE to go back through the insulation, got hotter than hell...a
great heat transfer was taking place!

It's sitting on the floor next to the printer, tonight, testing. The
wattmeter still sits on 71W when it's running, which I take to be about
15% duty cycle on my stopwatch after the initial cooldown and
temperature stabilization to 38F on the top shelf away from the evap.
The thermometer inside the little box evap sits on 8F at about 2/3
thermostat setting and should keep the icecream hard...(c;

There's two can/bottle racks with a holding bar in the door, which is
not damaged like my other R12 fridge (much older). None of the plastic
is cracked anywhere. I assume this means it spent ZERO time in a
college dorm full of Bud.

I'll clean it up tomorrow and swap it for the 4cuft currently in my
stepvan. That one runs R-134a and draws nearly 130 watts after it
stabilizes...reducing my AH drain to half with still plenty of room to
keep the colas and sandwiches cold on the Honda or inverter off the
house batteries (330AH golf cart beasts.)

I'm also going to see....I think the nice door on this fridge will fit
on my favorite old R-12 fridge, the one with the 40 watt vibrator
compressor from Sweden. That's the most efficient little fridge I own
but its door has gotten so leaky and hard to keep closed I gave up and
set it aside. This nice oak-grained Kenmore door will restore it to its
former glory. THAT fridge will run off a 75 watt inverter that is built
into a cigarette lighter plug! 40 watts = less than 3A drain off
13.8VDC, but I'm going to compare the AH drain over 4 hours between
these R-12 units. The compressor model may be more efficient than the
vibrator compressor, leading the new fridge to win the AH
Contest....from lower runtimes than the vibrator runs.

I'll be in the lab with my Linux tablet running spreadsheets if Algore
calls for advise....