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Tex
Dave's not here
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join:2012-10-20
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1 recommendation

reply to Jack_in_VA

Re: [Appliances] Is there a fridge that works correctly at any temperature?

said by Jack_in_VA:

The refrigerator/Freezer shuts off when the temperature outside is low enough to keep the inside of the Refrigerator lower than the thermostat is set. So when the Refrigerator temp is satisfied the unit does not run so the temp of the freezer rises to the ambient of the Refrigerator. It has nothing to do with the temperature of the compressor or lack of a compressor heater.

This is the answer to the OP's issue.

Low ambient conditions can adversely affect the refrigerant and the system's ability to function properly. Commercial refrigeration systems (outside units) that are designed to operate in low ambient conditions use devices that keep the discharge pressures high enough to allow proper refrigerant feed to the evaporator coil metering device. In addition, these systems use compressor crankcase heaters to boil off any liquid refrigerant that migrates to the compressor during the off cycle. Compressors don't compress liquid and those that try to compress liquid can and do crater. Also, liquid refrigerant in the crankcase can cause oil to be flushed from the compressor leaving little to no lubrication to the mechanical components. Domestic refrigerator/freezer units are not designed with low ambient temperatures in mind. They may or may not operate as designed and doing so may shorten the life of the compressor.


Jack_in_VA
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join:2007-11-26
North, VA
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2 edits
My fridge in garage


Tex
Dave's not here
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Domestic refrigerators/freezers are not my forte'. That's why included "may" in my last statement. I do know that during all my years in commercial refrigeration I have experienced compressors that have continued to function for years even after having been exposed to operational deficiencies that should have caused most compressors to fail. Conversely, I've seen relatively new compressors fail for unexplained reasons.

lutful
... of ideas
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join:2005-06-16
Ottawa, ON
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reply to lutful
Click for full size
Danfoss describes a compressor failure mechanism in low ambient temperature:
»www.danfoss.com/NR/rdonlyres/210···7web.pdf

lutful
... of ideas
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join:2005-06-16
Ottawa, ON
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Yet another bulletin on low ambient operation.


54067323

join:2012-09-25
Tuscaloosa, AL
reply to Tex
said by Tex:

Domestic refrigerators/freezers are not my forte'.

Unlike commercial units, residential refrigerators/freezers units are I don't want to say undercharged, but they are minimally charged, and unlike the diagram above, the condenser is fed by the compressor to the top of the condenser where as the hot gas it dissipates heat and gradually travels down the condensor it as it changes from gas to, a vapor, and finally to a liquid and since a liquid being heavier than gas, it collects at the bottom of the condenser where it feeds a cap tube connected to the evaporator.

The reason they can get away with this is, in domestic units the heat load doesn’t vary a whole lot in comparison to commercial units, it is also why the majority of the "residental" units don’t use expansion valves, cap tubes are just fine.

As such, due to the small charge, the chances of liquid making it back to the compressor itself, is very remote and even if liquid did make it to the shell under very low ambient, the heat from the motor will flash it off within the shell.

As an expmple this is a small A/C compressor I sliced open, FWIW residential refrigerator/freezer compressors are built the same way.

The return line is not connected to the compressor, it dumps into the shell.


Return line entering shell


Then it flows through the windings.


Flows down on the windings


And finally enters the compressor near the sump.


Then into the compressor near the sump


Then back out through the side of the shell.


And back out the side to the condenser


54067323

join:2012-09-25
Tuscaloosa, AL

1 edit
reply to Jack_in_VA
said by Jack_in_VA:

The refrigerator/Freezer shuts off when the temperature outside is low enough to keep the inside of the Refrigerator lower than the thermostat is set.

By the way this is exactly what is happening, the compressor of a residential refrigerator is controlled by the thermostat in the food compartment, and as long as that food compartment is cooler then what the thermostat is set for, the compressor and therefore the refrigeration will not come on, and if it remains off long enough, the freezer will assume the same temperature as the food compartment defrosting whatever is in it.

Sorry, but is just how they work and the only real solution, if the OP cannot move the frig to a conditioned space, is to buy a small chest freezer, which by the way unlike a refrigerator/freezer will really freeze the food without that nasty frost the auto-defrost system causes.


54067323

join:2012-09-25
Tuscaloosa, AL
reply to Jack_in_VA
said by Jack_in_VA:

When the compressor does run it's start cold as there is no crankcase heater.

Internally with those little fractional horsepower compressors there is no need for a crankcase heater, the compressor doesn't sit in the oil which is very thin anyhow and they are built inexpensivly with tolerances that allow them to operate undamaged under a very cold startup.

On top of that if it is so cold the compressor will not spin up fully it will kick out the overload, which will reset and it all starts over and while this is happening the windings are heating up the internals, himm that sounds like what a crankcase heater does.

When the ambient temp is below 40, the thermostat is happy and the compressor is never called into service. The result is that the freezer eventually settles in at ambient temp, too.


What a concept, speaking from experence.


54067323

join:2012-09-25
Tuscaloosa, AL
reply to Jack_in_VA
said by Jack_in_VA:

My fridge in garage

Where's the beer???


Tex
Dave's not here
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reply to 54067323
That looks like a rotary compressor. Not all residential refrigerator compressors are rotary. Reciprocating compressors have crankshafts, connecting rods, pistons and valves. I don't mean to be rude, but I don't need a lesson in the refrigeration cycle. Besides, you are not quite accurate in your description. Thanks anyway, though.

Mr Matt

join:2008-01-29
Eustis, FL
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reply to aurgathor
Check this out. It will allow a Frigidaire refrigerator to be used where temperatures run from 34 degrees to 90 degrees F. See this Garage Refrigerator Heater Kit. Designed to fit top-mount Frigidaire refrigerators.

»www.frigidaire-store.com/gakithecokit.html

Found here:

»www.frigidaire-store.com/refrigeration.html

Fits some of the refrigerators shown here:

»www.frigidaire.com/products/Kitc···erators/


nunya
LXI 483
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O Fallon, MO
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Already on first page.

lutful
... of ideas
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join:2005-06-16
Ottawa, ON
kudos:1
reply to Mr Matt
said by Mr Matt:

Check this out. It will allow a Frigidaire refrigerator to be used where temperatures run from 34 degrees to 90 degrees F.

»www.frigidaire-store.com/gakithecokit.html

Do you know if that 34F is because of the fridge thermostat's lowest setting? Or something to do with R410A refrigerant usage in residential fridges?


54067323

join:2012-09-25
Tuscaloosa, AL

1 edit
reply to Tex
said by Tex:

That looks like a rotary compressor. Not all residential refrigerator compressors are rotary. Reciprocating compressors have crankshafts, connecting rods, pistons and valves.

But in the end they still take a gas at one pressure and change it to another pressure.

I don't mean to be rude, but I don't need a lesson in the refrigeration cycle.

I didn't go over the refrigeration cycle, I simply demonstrated how any possible liquid would be flashed off before it made it to the actual compressor.

Besides, you are not quite accurate in your description. Thanks anyway, though.

As in???


54067323

join:2012-09-25
Tuscaloosa, AL
reply to lutful
said by lutful:

Or something to do with R410A refrigerant usage in residential fridges?

R410a is not commonly used in residential refrigerators, R-12 or R134a is the gas of choice in that application.

R410a is used however in residential air conditioners and deep freezers.


54067323

join:2012-09-25
Tuscaloosa, AL

1 edit
reply to Mr Matt
said by Mr Matt:

Check this out. It will allow a Frigidaire refrigerator to be used where temperatures run from 34 degrees to 90 degrees F. See this Garage Refrigerator Heater Kit. Designed to fit top-mount Frigidaire refrigerators.

»www.frigidaire-store.com/gakithecokit.html

FWIW all that device does is heat up the thermostat in the food compartment forcing it to periodically run the compressor to prevent what Jack so correctly describes as the OP's actual problem.

Unfortunately that answer has been somewhat buried in theories and over thinking unrelated to that problem.


Jack_in_VA
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North, VA
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+1

Mr Matt

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reply to 54067323
said by 54067323:

FWIW all that device does is heat up the thermostat in the food compartment forcing it to periodically run the compressor to prevent what Jack so correctly describes as the OP's actual problem.

I found this description when I was searching for a refrigerator last spring, to install in my garage. It confirms MatrixHDV's comment. It also illustrates how to install the heater.

»www.grilling24x7.com/fridge.shtml

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
said by Mr Matt:

said by 54067323:

FWIW all that device does is heat up the thermostat in the food compartment forcing it to periodically run the compressor to prevent what Jack so correctly describes as the OP's actual problem.

I found this description when I was searching for a refrigerator last spring, to install in my garage. It confirms MatrixHDV's comment.

I took their photo and added some comments for some rational thinking about the supposed problem and how this solution solves it.

From their official description: this garage refrigerator heater is ideal for fridges located in garages or basements where the temperature drops as low as 34 degrees Fahrenheit.

Such a heater element could easily raise temp inside the plastic box to 50+ F when fridge air is around 34F. So compressor would turn on and evaporator would remove some more heat from the air in the fridge compartment, that is the idea, right?

We can obviously get the 90F upper limit for ambient with such a heater installed ... but why would there still be a 34F lower limit for ambient with this solution ???


54067323

join:2012-09-25
Tuscaloosa, AL

4 edits
said by lutful:

but why would there still be a 34F lower limit for ambient with this solution ???

Because once the ambient hits 32F or lower there is no need to run the compressor to keep the freezer frozen and that point the food in the food compartment will begin to freeze and possibly be damaged, so by picking 34 as the lower limit, they are not misleading anyone into thinking the device will make a refrigerator operate properly in an ambient temperature lower than 34F.

Such a heater element could easily raise temp inside the plastic box to 50+ F when fridge air is around 34F.

That's a heck of an assumption.

lutful
... of ideas
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join:2005-06-16
Ottawa, ON
kudos:1

1 edit
reply to lutful
said by lutful:

said by aurgathor:

Is there a refrigerator that would work correctly regardless of the outside temperature? (at least down to 32F)

Your post reminded me of a CBC documentary where the Inuits in the Canadian arctic were installing fridges that were shipped in during the one unfrozen month of the year.
Anyway, whatever brand they buy will work for you too. I have to check.

I asked around and the Dometic WAECO CoolFridge is the answer to the original question.

They can keep Freezer temp at -18C and Fridge temp at 4C at any ambient ... from the tropics to Arctic to Antarctica (really).

*** Residential Fridge/Freezer labels specify "Climate Class" which is the allowed range of ambient temperature. Operating outside that range is apparently NOT supported by the manufacturer warranty.

Climate Class Minimum Temp Maximum Temp
N 16 Deg C 32 Deg C
SN 10 Deg C 32 Deg C
ST 18 Deg C 38 Deg C
T 18 Deg C 43 Deg C

(SN/T goes from 10C to 43C)


aurgathor

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Lynnwood, WA
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reply to 54067323
said by 54067323:

Sorry, but is just how they work and the only real solution, if the OP cannot move the frig to a conditioned space, is to buy a small chest freezer, which by the way unlike a refrigerator/freezer will really freeze the food without that nasty frost the auto-defrost system causes.

Well, there are actually several solutions, and some are better than others.

I set everything to maximum, and the freezer started working again. Of course the next morning my milk was solid.... (I removed all my vegetables from the food compartment before and left them in an unheated room so no real damage)

I could also buy an outdoor rated fridge, which I'm considering for next year, even if I finish insulating my home.

For the time being, I think I'll just try to hack my fridge: there is already a 'heater' in the food compartment -- the bulb that turns on when the door is opened. I'll add an extra switch that allows me to keep the light on all the time -- 25W may not look like a lot, but I think it should be more than enough in an insulated enclosure.

--
.sig

lutful
... of ideas
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join:2005-06-16
Ottawa, ON
kudos:1

1 edit
said by aurgathor:

I could also buy an outdoor rated fridge

You can also buy a residential model which has separate thermostats for freezer and fridge sections. Check the "climate class" rating - I mentioned common codes in previous post.

*** Whirlpool Gladiator garage fridge/freezer is rated from -17C to 43C. As close as you can get to the WAECO but much bigger in size.

AEKDB

join:2004-03-07
Towson, MD
reply to nunya
Yes I've used the kit that nunya linked for the fridge in my garage. Fridge works great now in the winter when garage gets into the 30s.


54067323

join:2012-09-25
Tuscaloosa, AL

1 edit
reply to aurgathor
said by aurgathor:

I'll add an extra switch that allows me to keep the light on all the time -- 25W may not look like a lot, but I think it should be more than enough in an insulated enclosure.

Well that will probably be more than enough considering the garage heater is rated at 1/2 watt and it can do the job.