Still not happy with my new 3 Way fridge

Hi David
I have an old chescold, on gas and 240v, it will freeze everything unless it is turned down to the lower end of the thermosat. On 12v it will maintain temperature if chilled down first.

cheers

Crazie

Hi David,
I have a Chescold RC1180 connected it to 240v and for interest sake put a recording thermometer connected to its probe in a 4 litre tub of water and recorded the drop in temp over a few days.
It was inside the house which varies in temp at this time of year from 20-25 deg.
The water temp was 19 deg when put in and it took 7 hours to get to 0 deg. It took 11 hrs all up to get to -5 and 24.5 hrs to get to -15 then I turned the water container on its side, fitted the freezer separator and put in some hot cans..as you do.
They took the temp up to 15 deg in the fridge section and then it took a further 7 hrs to get them cold enough to drink 0 deg.
I tell you this to give you an idea of what mine does on 240v. I have had it at Exmouth in May on gas and have no complaints...never drank hot beer, however not over fussed about it on 12v but for my purposes,it will do.
Jeff

Whilst I'm not exactly sure of the chemistry involved, 3 way fridges work on the principle of the gasification (vapourisation) and condensing of an ammonia compound within the fridge cooling circuit. This chemical/physical change can only reduce the temperature in the fridge to about 28c less than the ambient temperature at the time.

So, if it's say, 30C where the fridge is situated, the temperature in the fridge cooling circuit can't go below 2C. etc,etc. It the ambient temp is 20C then it can go as low as -8C.

Bilbo

First question: is your thermometer/thermocouple accurate? Check it against something else or make an ice slurry, allow it to sit for 30 mins. and that should give you a pretty accurate 0C.

Ensure you have the fridge half or more full when measuring temp, an empty fridge may oscillate easily in temp.

Keep the probe immersed in water in the fridge thus ensuring good thermal contact.

Ensure the lid of the fridge is properly closed and sealing - not as obvious as it may seem.

Ensure the fridge is _LEVEL_

If I put (say) 4 x 2lt milk bottles filled with tap water into my Finch 3 way I would expect it to take somewhere between 12 and 24 hours for the fridge to pull back to 2 or 3 degs. in a ~25 deg ambient.

Mike Harding

absorption fridges do not have the ability to pull very low temps...
however, they are fairley good at what they do.....

These units require heat as the source of generation to make them work.
12v operation as its the car battery would I suspect have a limited size heater to help conserve supply and hence would not provide an abundant supply of heat...

gas on the other and I suspect 240v should be able to get the temp lower due to unlimited supply of heat/power...

they do work harder with more applied heat

also there will be a temperature differnce between product and cabinet air temp...this happens in all fridges....its just that the temps would be different. 5-6 degrees is adequate for short term refrigeration....most domestic fridges do not operate at below 5 ....

short term refrigeration is; fresh produce 1 week...cooked produce up to 4 days. You could keep it longer by lowering temp setting but you will find that the even in the domestic fridge you run the risk of freezing other goods ..and this then can reduce product life...
meat is especially hard to keep in a fridge so its best to freeze or cryovac if you want to ensure its good for a week or longer.

Main reason why product can not be kept for very long periods in fridge is the compromise manufcaturers have to contend with to average out the different temperature/humidity requirements inside the fridge for the varied product placed in the fridge...ie meats generally require colder temps than vegies at different humidty levels..while that stuff commonly refered to as Nectar of the Gods doesnt care about humidity just 2C.

on 12V the trick is to have it cold first.
I leave my Chescold on 240 all the time. I have a couple of milk bottles full of ice in there, and they stay in there as a sort of "ballast." I run the fridge on 12V all day and put it on gas at night and have no problems. If I try to do what you are doing I get the same results. My advice. Freeze some milk bottles (plastic) in your home frezer. Put them in the fridge. Run the fridge on 240V for a few days. Repeat your experiment.

To reinforce others....I have to turn my thermostat way down on the Chestcold 3 way on cool nights or it will freeze eveything. As for readings....I use a small digi thermometer on a 5 m cable - output is on the console - thermocouple end is on the underside of the fridge's lid. ! My rationale is that in a tightly packed 3 way, you can have warm tucker at the top while the gear at the bottom is quite cold - not a true reading of the worst case scenario - better to have a satisfactory reading at the top, knowing the food down lower is colder. Works for me.

Hi

Whilst I don't have a 3 way fridge, I did have a little bit of a problem with our engel pulling down quick enough with a 2 zone on it.

We discovered that the lid wasn't sealing properly so it couldnt stack the cold efficiently.

Easly way to check it the lid is sealing properly is to put a dolphin torch or similar turned on inside the fridge facing upwards, close the lid and check for signs of light around the seal.

It might not be your problem, but it may be worth checking.

Cheers

My waeco cooler is set to cycle at 4.5 degrees at the top. That's about 2.5 at the bottom. But when using the cooler (opening closeing etc etc) it'll go right up to 9c at the top on a hot day. The food itself stays pretty cold though, it's the air temp that's fluctuating like crap not the food.

I also use some of those blue freezer packs (the soft ones). Get the thick ones they work brilliantly. I make sure that they are packed around the meat to help keep the temp more constant around there. They will last a week in the bottom of the fridge as they don't get a chance to defrost and they just help stabalise the temps, takes up the slack when the fridge can't cope from being opened all the time.

My drinks are always cold, even when the temp guage is right up there.

Hi David T,
The ambient temp in my house is around 24-25 deg. (Still on 240v)
I just dropped the thermocouple back into the freezer section where the ice is and the temp is -14 deg...the beer, sadly has gone.
I wouldnt expect this temp up North but It would still keep the stuff frozen if covered as suggested in a previous reply.
I am sorry Iam unaware of the fridge you are talking about and can only let you know what mine is doing.
Good luck.

Hi david T,
You are right, there is a 40ish deg difference in the temp, however, I just checked out the current price of these suckers, (I bought the blue one a couple of years ago for around $1100) and they are now around the $1200 mark. I think you suggested that your style of camping doesnt lend itself to the compressor type of fridge, however, you can get a stainless engel at around the $900 mark( on special I think) or an evakool 50 litre for around $1200 you may give a bit more thought to a change. I have the rc1180, which is a 50 litre job but will also get (if Iam allowed by SWMBO and can afford it) the Evakool. If you must use gas...get the RC1180 you wont be dissappointed.
Jeff

Sound decision David.
Let us know the results of your experience, I will be interested to hear how you go.
Good night.
Jeff