Shoreline 12v fridge - problem?

[Johny London]

I'm in two minds if a/ it's just not a very good fridge or b/ its not operating as it should.

 

Last couple days its been 8c in the fridge and I think I can live with that, it will only get better once the heat passes. Also I put a 2l bottle of pop in the freezer for 1/2 an hour - when I remembered it the next day it was solid! So the freezer seems very powerful, not so much the fridge, hence my leaning towards b.

However, because I can turn the inverter off, I have enough power to keep the fridge on overnite - the result being I bought stuff for more days and for the freezer too. Normally, turning the old one off at night I didn't like to have more than a couple days stuff. So now rather than being 5 or 6c in days and prolly double that at night, it's an even 8c. 

I'd like to get a bit more cooling out of the fridge bit, but I can live with it - too cold and all the salad stuff gets messed up anyway.

 

I think the manufacturers just err on the side of caution with a lot of what they say - who ever heard of a fridge or freezer not easily cooling stuff?

[cuthound]

2 hours ago, smileypete said:

Sorry but fridge compressors have almost zero in common with car air con compressors, other than they compress refrigerant gas. Where are the mechanical seals on a domestic fridge compressor? ?

 

People often mis-diagnoise the need for regassing fridges as it's the first 'expert conclusion' they mistakenly jump to, but it's pretty rare in practice and there's plenty other possibilities.

 

Back to the OPs question, a look in the manual reveals the following statements:

 

http://www.shoreline-marine.co.uk/admin/document_library/RRInstructions_BD35ONLY.v21_150618.pdf

 

'Note - These 12/24 Volt DC freezers are designed to store pre-frozen foods, not to freeze down large quantities of fresh foods. Expect the motor compressor to run for very long periods without cutting off if you attempt to freeze quantities of fresh foods.

 

Caution: If the room temperature starts to rise above +25ºc the motor compressor will begin to run for longer periods and consequently require more battery power. Room temperatures above +30ºc could result in correct storage temperatures not being maintained inside the appliance. '

 

The second para to me implies that when you reach temps above 30°C in high summer, the compressor may well need to run 24/7...

 

 

 

 

 

Whilst I accept that physically there is little in common with domestic fridge and car compressors, they do operate on the same principle (using a piston to compress the gas), and carry lubrication oil in the liquid refrigerant. Failure to get temperatures within 25-30°C of design temperature definately points to insufficient refrigerant. 

Edited August 9, 2018 by cuthound
Spillung

[cuthound]

 Duplicate post removed.

Edited August 9, 2018 by cuthound
Removal of duplicate post

[smileypete]

It's rare for domestic fridges to leak refrigerant unless the pipework is damaged, which is rare in itself unless someone attacks the frost in the icebox with a knife.

 

Without knowing that for sure, the layman guess is probably right only 2-5% of the time if that. Of course everyone thinks that their own snap diagnosis is good.

 

In the OP's case I'd say it's unrealistic expectations, coupled with oversight of parts at the end of the manual. If the 12V compressor runs about 25W and at typical fridge freezer mains compressor runs about 100W, it's fairly clear which one has far more grunt.

 

My mains frig will turn a slightly cool beer put in the icebox into an ice cold one in an hour if I run it non stop. That'll do me, well worth about 100Wh.

Edited August 9, 2018 by smileypete

[Mike Hurley]

Air con compressors should be turned on every month so the oil circulates to lubricate the rubber seals, i guess if a fridge works on the same principal then if it has been left unused for a long period then it could loose some gas. My cars and house air con have been fine using this method.

[dor]

On 04/08/2018 at 20:48, Mike the Boilerman said:

 

It's rather odd isn't it.

 

Trawling the depths of my memory I vaguely remember a previous discussion of this and I've an idea it is to do with larder style fridge freezers having two separate temperature spaces but still only one compressor. So the two compartments are not cooled independently but both at the same time and when one gets cooled, so does the other. When one is cool enough, the other gets no cooling power either. 

 

This leads me to wonder if the thermostat sensor is in the more important of the two chambers, the freezer. So cracking open the freezer door in really hot weather might force the compressor to run for a higher proportion of the time, thus cooling the fridge compartment more.

 

So the designers decide it is better to err on the side of having the fridge compartment a bit on the warm side rather than too cold, and freezing the eggs, milk and beer solid.

Bit late to this one...

I think a lot of fridge-freezers are just glorified fridges with a big ice box.  The thermostat operates in the fridge, and the 'ice box' should get reasonably cold.  Most ordinary fridge-freezers come with a warning not to operate them in an environment below 5deg and not run them in an outhouse or garage.  This is because if then air temperature is below the thermostat setting, the compressor will not operate and the freezer section will thaw out, just the same as in a domestic fridge.   Also this is why they are not recommended for freezing things, but just for keeping already frozen things frozen.

 

My own Shoreline 12V fridge is rated as 4*.    Set on '2' the ice box will get down to about -11.  If I turn it up to '6' the ice box will go down to -18.  It will readily freeze a pint of milk "yellow" solid in a couple of hours. This in a 25 degree or more ambient temperature.   But not many shoreline fridges have a 4* rating; they just seem to use whatever cabinets they can get (presumably cheaply) at the time.

[Glynn]

Just get a proper fridge, a mains one.

[mrsmelly]

9 hours ago, WotEver said:

And still not get the temp below 10C...

As in post 4

1 hour ago, Glynn said:

Just get a proper fridge, a mains one.

Correct. Absolutely good info.