Absorption Fridges

[GEOFF.PAULINE]

Hi.
Been looking at 3 way Fridges. Most have an absorption system.
I have looked at how they work etc , But when I look at the details of some for sale they indicate that they will cool to 15 degrees below ambient temperature when on gas.

Now for my naïve question , as an example if the Temperature is 40 degrees ,less the 15 that the fridge cools , that leaves it at 25.

You cannot store food at 25 degress , so what am I missing here ??

Thanks Geoff.

[robcaz]

The majority of the cheaper 3way fridges that are on the market do not have a thermostat on gas, so you cannot adjust the flame, there is only one speed & that's flat out. They will only cool down internally to 25 degrees below that of the ambient temperature.

Most of the cheaper 3way absorption fridges like Companion, Gasmate, Jackeroo, Repco & the smaller Waeco's are manufactured by Mobicool in China.

CSIRO recommend that food be kept at below 5 degrees to be safe http://www.csiro.au/Outcomes/Food-and-A ... afety.aspx

We had always camped with an absorption 3way fridge until setting up the 12volt system in the camper trailer which allowed us to lash out & buy an Engel. This Repco fridge replaced a Finch fridge we had for 25 years http://www.campertrailers.org/repco_fridge.htm

It is handy to have a thermometer with a probe in the fridges core so you can keep an eye on the internal temperature during hot weather, especially more so if you have meat in there.

There are a few ways you can improve the thermal qualities of the fridge in hot weather. It is best to put the fridge in a cool position like in the shade under the camper awning. We had even placed a wet towel over the fridge in very hot weather avoiding blocking the vent across the back.

Another idea is to line the inside with Techni Ice. We also used one sheet over the contents with great results. Techni Ice recommend a minimum of 1 sheet per 7-8 litres of cooler size http://www.techniice.com/dry-ice-packs-usage-tips

Keep the fridge as full as possible, it is hard trying to keep air cold. Even crumpled up newspaper helps to fill the gaps. Only replace one thing at a time, if you take a drink out, replace it with one at ambient temperature & not six at once.

On the other hand during winter, we found it was best to turn the fridge off before bed or everything would freeze & you could hear cans popping early morning.

Turn the fridge on 240volt for a few days before leaving & pack it so everything is cold. This will help keep the 12volt power consumption down when travelling to camp. They are heavy 12volt power users at around 15 amps, so you do need to consider running decent twin core cable to reduce voltage drop. I had run a dedicated heavy cable from the battery under the bonnet in the Patrol to the fridge in the back with little voltage drop. This resulted in the fridge freezing when driving. Redarc's cable calculator will give you the size you need & yes that's the size you need http://www.redarc.com.au/handy-hints/ca ... calculator

You will find an article written by Ian in the tech tips pages on 3way absorption fridges http://www.campertrailers.org/3-way_fridge.htm

[Burto51]

Have been using an absorption fridge for over 20 years, first one was a Chescold after many years of use it died and was replaced with a Chescold which is now badged as a Domectic, never used anything else never will, see I can't dance so I would be a failure at the solar panel dance. LOL
My fridge has a thermostat that works on both gas and 12 volts but not on 240volts, as you know these fridges use a heating element to cause a change of state of the "refrigerant", my fridge 's element is 120 watts and therefore will draw at a supply voltage of 12 volts a current of 10 amperes never anymore.

If you consider the Power equation which states that "the power consumed or created in an electrical circuit is given by the formula Voltage X Current = Power. It can be seen that with a fixed wattage load if the voltage increases then the current will reduce proportionally.

In regards to the actual temperature, must admit that I have never used a thermometer to test the temperature, but after many years of use, we have never had a problem with spoilt food or thawing out of frozen items, in fact when on gas we have to be careful to turn the thermostat down or off at night to prevent freezing in the fridge section. At the gathering at Hawks Nest this year, we would turn the fridge off at night. We also use the freezer section to freeze fresh meat when we resupply on a long trip, say 6 weeks to 3 months(at Frying Pan creek on the Australia Day weekend I froze some water in a freezer bag for the grandies about 500ml took around 1 hour), so there is no question about the cooling capacity on gas, on 12 volts in the car when travelling the thermostat is also turned down to low.

I use a 15 amp fuse which has never failed so have never experienced a current draw of that size. Must be lucky

Everyone will use the equipment that suits their budget and needs, do your research and talk to others, then make up your own mind don't be swayed by the hype. My entire setup suits me, longest time away 3 months, no use of mains, no solar panels and no generator.

Regards
Greg

[nomudfalcon]

Geoff Pauline g'day,
By this time you may have purchased what you feel is best for your setup, enjoy the trips.

We would have to agree with Greg, we have had a Domectic for about 2 years now - can't fault it touch wood, testing settings before we started out gave us a good guide as to gas usage(using travel scales).
We never run it on 12V too thirsty, 240 is great.
On the run we use a 60lt Waeco then swap. We tend to camp one spot for 2 -3 weeks so setting the Domectic up and swapping the cooking/fridge gas bottles over when the weight gets down in the fridge bottle. Running 2 x 4.5Kg and can squeeze 18 to 20 days if we are watchful on how cold we need the fridge(not away in summer). Starting out we freeze meat and bread, enough for 2 weeks then use the fridge for drinks only, once the meat is gone we then start tucking into canned grub then if over filling the plates, onto the dreaded packet stuff and can't wait for takeaway on the way home .

Safe trips
John & Judy

[SocialGeoff]

Yeah 3 way fridge is what I want...still looking...Engel be nice but gas is the way to go so will keep looking...love the Trailblazer fridges we had in the Army but at $2300 now are a bit pricey but best beer neck injection cooler u ever buy....
Had a new Dometic in my caravan then the thermostat shit itself after 5 yrs...plus once the tempature got over 35C it was useless for a cold beer..n I had computer fans to assist cooling and a shade cloth curtain built for the side external wall for the caravan even...
So now till I find a fridge I like I use my large fibre camping esky..load it with two frozen 2 gallon buckets of ice...then wrap it up with a blanket of double layered inner house wall liner...so I just get it...cut sheets of it big enough to cover the entire esky...so put that in the back of my ute...place esky on top...have it sitting up a bit on one side so water can drain out n also have straps under the esky to hold the blanket in place..and I have found that the 10mm aluminum thick perforated sheet I found at the scrap yard that sits in the bottom of the esky that I also freeze aids in cooling...plus keeps the ice off the inner floor of the esky...cause water kills ice...so yeah one day they will make a robust 3 way fridge for camping...till then I live in the ice ageeeee

[Andreas]

We have a Dometic Chescold RC1180, top of the range gas fridge and love it. It has a temp adjustment when on gas and works exceptionally well. I often have problems with things getting too cold (ie carrots freezing) than things being too warm.