On Fri, 18 Jul 2008 15:41:19 +0000, in message

Larry wrote:

I wonder how one of these little $100 fridges would work with their useless
little freezers filled with blocks of aluminum as holding plates so you
could flip them on when you crank the engine (or install a simple relay to
do it automatically). Btu is Btu. It's not rocket science. The more you
open it, the more it draws. The cheap one's R-value could be easily
increased with some sheet styrofoam to pack it in with or glued to its
sides.

I have some big aluminum heat sinks I got from somewhere. I think I'll
play a little with them stuffed into the little freezer and see how that
works as a holding plate....hmmm...(c;

Badly.

You would be much better off filling the freezer with a phase change
fluid that melts/freezes somewhere in the desired temperature range.
Water, for instance...

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

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....

On Sat, 19 Jul 2008 02:33:54 +0000, Larry wrote:

///
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.
///The little compressor is SO
quiet you can't even hear it start!

/// 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;

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

Forget about the pleasures of sailing a fresh warm breeze, it's
nice to see simple joy radiating off into the net: about finding a
bargain, running tech checks, looking forward to icecream
and chill beer afloat. Gotta love those dorm fridges.

Brian W

Ryk wrote in
:

You would be much better off filling the freezer with a phase change
fluid that melts/freezes somewhere in the desired temperature range.
Water, for instance...



I have lots of freeze packets, both in plastic bags and hard plastic cooler
packs made to go between the cans. I'll try them, too, as a cold plate.

On Jul 18, 9:34*pm, Larry wrote:
Ryk wrote :

You would be much better off filling the freezer with a phase change
fluid that melts/freezes somewhere in the desired temperature range.
Water, for instance...

I have lots of freeze packets, both in plastic bags and hard plastic cooler
packs made to go between the cans. *I'll try them, too, as a cold plate..

If you have two sets of the freezer packs you can freeze one during
the night and morning, move it to the fridge compartment just prior to
the hottest part of the day, simultaneously moving the other (thawed)
bunch of freezer packs to the freezer. I've found it works wonders.