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ECO2 ... 12volt refrigeration with little or no battery drain!! See 'System Packages' Option one.

System selection and power consumption charts:

BELOW LEFT: The blue charts below left provide a daily power consumption estimate for various sizes of cabinets, and insulation thickness
First select your cabinet size on the left then follow across to the daily 12.5VDC consumption for your insulation thickness. (Halve for 24VDC)
Power consumption estimates are for top opening cabinets with typical use during Australian summer conditions. Expect less at other times.

BELOW RIGHT: These charts indicate the suggested Ozefridge package to suit the various cabinet uses, sizes and insulation thickness.
Those with a T indicate twin plates are suggested, while red indicates water cooling is recommended and purple indicates optional C480 (with BD80 compressor) with water cooling is essential.

Ozefridge specializes only in the manufacture of refrigeration systems to suit existing cabinets or cabinets built by others.

Here are some cabinet construction and system installation suggestions.

Adequate cabinet insulation quality and quantity is essential when operating a refrigerator or freezer from limited power supplies. The lining materials used, cabinet shape, door / lid location and seal are all important to consider if best performance and efficiency is to be achieved.

Cabinet Insulation etc.

While the refrigeration system removes heat thus lowering the fridge / freezer cabinet (and products within) to the desired temperature, the insulated fridge / freezer cabinet's job is to prevent more heat entering.
Unfortunately no cabinet is 100% successful at resisting heat penetration and so the cabinet will eventually warm up requiring the system to run again. The better the cabinet can resist heat penetration, and thus temperature rise, the longer the system remains off.
As an example a good cabinet may be unable to prevent say 20 watts of heat per hour penetrating, therefore if the system applied can remove say 100 watts per hour of running it will have to run 20% of the time. The same system applied to a cabinet letting 80 watts enter will run 80% of the time, while a very poor cabinet letting more than 100 watts enter would see the cabinet temperature rise and the system run continually.
For refrigerators we suggest a minimum of 75mm thickness of refrigeration grade urethane for walls and 100mm for the base. For freezers we suggest 100 mm for walls and 150mm for the base. (Heat rises as it attempts to penetrate the insulation therefore the base is most important and the top least important assuming it is not in direct sunlight.)
The insulation must be vapor sealed (enveloped) and preferably lined with non heat conductive materials such as plastic or fiber-glass. If metal linings can't be avoided, the metal must not run from the exterior to the interior without a broad thermal break. The same applies to lids / doors which should also have soft broad seals.

Single cabinet shapes etc.

Fig 1 & 2: Long, low cabinets and tall cabinets will produce stratification. (Variation of temperature) Some users prefer this as it allows items requiring different temperatures to be better catered for. For example, drinks are place nearer the eutectic plate while the butter, veg etc is afar. A cabinet circulation fan can be used to agitate the cabinet air, even out the temperature and speed up product cool down.

Fig 3: This sketch indicates that by installing the eutectic plate in the bottom of a tall cabinet, the stratification is increased to the point that the lower portion can be used to hold frozen items while the upper area can be used for normal fridge items. The grey divider indicated needs to be removable. (Often simply a towel or similar). This method is a compromise that while not a proper fridge / freezer combination cabinet, it will suit when frozen items are occasionally stored.

Fig 4: While top opening cabinets are more efficient, many prefer the convenience of front openers. This sketch indicates how the door can be part of the front providing ease of use without losing all of the cabinet's air when opened. Use of storage containers inside the cabinet also helps to prevent loss of cold air.
Generally the eutectic plate or plates are mounted as high as possible in the cabinet.

Large freezer or Fridge / Freezer combination cabinets & systems.

The Ozefridge twin eutectic plate systems suit freezers larger than 100 liter and the ultimate fridge / freezer combination cabinet. (See Fig. 8)
The twin plate system refrigerates both sides of the freezer cabinet providing more refrigeration where needed. The fridge side is refrigerated via the heat exchanger.
Each twin plate system has one refrigeration unit coupled to your choice of either twin T28-32, T35-32, T45-32, T53-32 or T50-38 eutectic plates.
To refrigerate the adjacent fridge area a thermostat controlled fan (orange) pushes air through a hole in the dividing wall into a stainless steel duct located on the freezer side of the dividing wall. Air travels along inside this duct and back out into the refrigerator area providing cooling for the refrigerator side without mixing refrigerator and freezer air and reducing ice build up.
This is a most popular system for those building a new cabinet or renovating.
Not only does the one Ozefridge twin plate system provide adequate refrigeration for the freezer, but also refrigerates the adjacent refrigerator cabinet. (See Fig 8)

Fig 5: This beautifully made fridge / freezer combination cabinet was owner constructed using Multipanel. The cabinet has three layers of Multipanel 30mm thickness high density urethane laminated. It is essential that combination cabinets are properly insulated and sealed as this one is.
The freezer compartment (Fig 5) has an Ozefridge Package Five twin system being a C450 refrigeration unit coupled to twin T50-38 eutectic plates mounted in opposite sides of the freezer area. The stainless steel heat exchanger duct can be seen on the freezer side of the dividing wall. This duct is only 12mm thickness and otherwise the height and width are custom made to suit each individual application.

Fig 6: This picture is of the refrigerator compartment side of the same cabinet. The Thermo-Fan unit is located over a 70mm hole through the dividing wall. When cooling of the fridge compartment is required the thermo-fan draws in air forcing it through the 70mm hole and into the heat exchanger duct. This air from the refrigerator is cooled as it travels horizontally along then out of the duct and back into the fridge compartment via the other 70mm hole in the dividing wall. (Left side)

Fig 7: This picture shows a stainless steel heat exchanger duct and two thermo-fans. (One on the right is upside down to show the air exit hole at the rear). The thermo-fan's thermostat will sense when cooling is required in the refrigerator side and start the fan. The thermostat can be set to suit your requirement like a home refrigerator. It also has an off position.
Temperature of the freezer area is controlled by the refrigeration unit's digital controller. The SS duct, as a heat exchanger, prevents the warmer/ humid refrigerator air mixing with the freezer air reducing the frost build up on the eutectic plates.

Fig 8: Packages with twin eutectic plates. The package with twin plates uses one refrigeration unit to refrigerate both of the eutectic plates. The eutectic plates can be a pair of any of our plate models. Both eutectic plates are located in the freezer compartment. (Twin plates must only be installed in the same cabinet, not seperate)
All twin plate systems should be water cooled for best results. Systems using the optional Danfoss BD80 compressor must be water cooled.
Twin compartment operating options.

Locate a twin in a properly insulated cabinet and use as a large freezer.
Locate in one section of a divided cabinet and operate as a freezer (Fig 5) and have a refrigerator in the second area controlled by a thermo/ fan unit. (Fig 6)
As above but operate both compartments as refrigerators.
As above but operates one compartment only as freezer or refrigerator.

The combination fridge / freezer cabinet using a twin eutectic system is popular with those starting a new project. The twin T50-38 plates are most commonly used for this application but other models may suit your cabinet dimensions better.

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Fig. 8 Below

Not suitable

Fridge