A concentrated ammonia solution is heated in a boiler and expelled as vapour. The pressurised ammonia gas is then liquefied in a condenser. Supplied with hydrogen, it evaporates and in the process extracts heat from the storage container. The ammonia gas then enters the absorber where it is reabsorbed in a weak solution of ammonia. Finally, the saturated solution flows back to the boiler where the whole cycle starts again.
The thermoelectric principle was discovered in 1834 by J.C.A. Peltier, which is why the temperature generating parts of thermoelectric systems are referred to as Peltier elements. Thermoelectrics are based on the fact that cold or heat energy (depending on the polarity) is generated when a DC current is conducted between different types of metal. The heating or cooling capacity is further enhanced by heat exchangers and air fans. Ideal for low and medium cooling volumes.
Compressor coolers operate using a refrigerant that changes from liquid to gaseous state in the evaporator. The evaporation extracts heat from the interior of the cooling unit – the temperature drops. The compressor draws in the refrigerant, compresses it and passes it on to the condenser. Here, the absorbed heat is released to the atmosphere. The refrigerant liquefies again and flows to the evaporator, where the cycle begins again.
Ingenious technology for even more versatile use: the Dometic CoolFun CK 40D Hybrid incorporates a high-performance compressor as well as a thermoelectric unit. In compressor mode (230 volts) it provides refrigeration and deep-freezing up to –15 °C, regardless of the temperature outside. The integrated thermoelectric system fills in when the cooler is used in the vehicle. Connected to the 12-volt battery it cools food and drinks up to 20 °C below the ambient temperature while driving. It is the ideal awning fridge – and just as great for your home or garden party.
It makes quite a difference whether you mostly drive the vehicle you use for work or leisure in a moderate climate or in the hot, sunny south. It’s a fact that the cooling performance of thermoelectric, absorption or passive coolers is influenced by the respective ambient temperature. Compressor coolers, by contrast, are independent from the ambient temperature and even permit deep-freezing. When the daytime temperature often rises to about 40 °C and more, as it tends to do in Spain, Greece and Croatia for example, thermoelectric systems cannot be expected to deliver satisfactory cooling results. Depending on where you place it, you may be luckier with an absorption cooler. If you want to be on the safe side, however, you are best advised to choose a compressor cooler for cooling performance in hot regions.
Pick a cooler to match the ambient temperature. It is an important aspect to consider when you decide whether it has to be a passive cooler, a versatile absorption cooler, a lightweight thermoelectric unit or a compressor box with cooling power independent of the ambient temperature.
You like to go on day trips and keep fruit and soft drinks nice and cool? Or are you on the road for weeks on end with your mobile home, truck or boat and therefore wish to take deep-frozen food as well? While an inexpensive thermoelectric cooler will do in the first case, the second situation definitely calls for a compressor unit.
Insulating effect depending on the ambient temperature
Refrigeration depending on the ambient temperature, ice cubes on the evaporator
Refrigeration depending on the ambient temperature
Refrigeration and deep-freezing from +10 °C to –22 °C (CFX)
Our tip: Dometic Cool-Ice passive coolers are an excellent choice for fishing trips. They keep bait and catch fresh for many hours without an external energy supply. A set of cold packs or ice cubes will do.
Is it okay for you to run your cooler “only” from the 12 or 24-volt vehicle battery? Would you like a 230-volt mains option as well? Or are you one of those camping enthusiasts who prefer cooling with gas? The Dometic cooler range accounts for all these energy options. Compressor units can even be run with solar power – a plus factor you should exploit when travelling in the sunny south a lot.
If gas operation is all-important to you, absorption cooling is your system of choice. Dometic compressor coolers excel for their energy-efficient operation. Integrated battery protection puts you on the safe side when the unit is powered via the vehicle battery. This feature is fitted as standard on all Dometic compressor boxes as well as the thermoelectric coolers of the TCX series.
12 volts / 230 volts / gas
12 volts / 24 volts / 230 volts
12 volts / 24 volts / 100 – 240 volts
Energy source wherever you go: Integrated cradle for a gas cartridge for the CombiCool ACX 40G absorption cooler.
In mobile applications electrical devices are mostly supplied from “limited energy sources”. That means energy consumption is a crucial factor to consider. The table below tells you how to calculate the consumption of specific cooling appliances. It becomes obvious that longer periods of use (e.g. more than 2 days) call for the energyefficient compressor technology. The owners of an absorption unit have an alternative, though: gas operation.
The noise emission of a cooler is not much of an issue while travelling in a car, boat or truck. It’s a different story when it is kept in the room you are staying or even sleeping in. If you – like most camping enthusiasts – wish to place your cooler under the awning, you are best advised to choose an absorber unit. This type of cooler is almost quiet. If the occasional start of the compressor does not really bother you though, you will be just as happy with a compressor box.
Of course we can deliver coolers in any size and volume you want. Please consider, however, that the larger the cooling compartment, the more energy is required. Moreover, a jumbo-size cooler is heavier and more difficult to store than a compact model. On the other hand, a compact cooler would hardly be sufficient for a family of five – they would certainly need more cooling capacity. The same is true for truck drivers, who tend to be on the road in pairs and for days on end. And, of course, skippers planning a long trip will require a different cooler than anglers who just want to safely store the catch of the day.
Conclusion: The cooler you choose should be a perfect match for you, your companions and your travelling habits, but also in terms of size and the space available in your vehicle.
For day tours and spontaneous picnics we recommend the thermoelectric TropiCool TCX 21 for example. In the morning you put soft drinks and sandwiches in it – in the evening it’s empty. It’s also great for everyone having to travel for work a lot. Long trips, however, require a somewhat larger and stronger solution.
Take the CoolFreeze CFX 50 compressor cooler for instance. It neatly fits into the storage compartment and is great for the occasional boat trip as well. Its greatest bonus is its incredible performance. The sun may be scorching hot, yet this unit plays it cool!
Do you have a portable cooler with a 12-volt or 12/24-volt connection, or are you planning to buy one? Then you will always have the option to run it from the mains too. With the matching Dometic CoolPower mains adapter you can use it on a mains socket at home, in the hotel, or in your holiday home. That will give you a much wider range of possibilities.
Dometic CoolPower EPS817
Mains adapter for hassle-free connection of thermoelectric 12-volt cooling appliances to the 230-volt mains.
Dometic CoolPower EPS100
Mains adapter for hassle-free connection of 12 / 24-volt cooling appliances to the 230-volt mains. Suitable for Dometic CoolFreeze CDF coolers.
Our BordBars are the best thermoelectric coolers for your car. What was formerly reserved for luxury automobiles is now affordable for everyone. TB 08 and TB 15 provide drivers and passengers with cool snacks and drinks, and they can even keep hamburgers and chips warm. Placed on the front passenger seat or the centre of the rear seat, they are fastened with the safety belt.