When traveling by car or When living in a motor home, many owners are faced with the choice of refrigeration equipment, which can be powered by a gas cylinder or on-board network. Unlike conventional kitchen units, which are based on a compressor, a completely different physical process is used here. Absorption refrigerator is a device that can maintain cold without moving mechanical parts, which makes it almost silent and durable.
The essence of the technology lies in circulation a refrigerant, usually ammonia, which is absorbed by water and heated by an external energy source. It is the absence of a vibrating motor that allows such systems to be used in sleeping areas and medical institutions where silence is a critical factor. In this article, we will analyze in detail the design of the system, its advantages over compressor analogues and maintenance features.
The principle of operation of the absorption system
The fundamental difference of this technology is that the compression of the gaseous refrigerant occurs not by a mechanical piston, but by chemical means. A water-ammonia mixture circulates in a closed circuit, where water acts as an absorbent and ammonia as a refrigerant. Heating element, powered by electricity or gas, brings the solution to a boil in a generator, separating gaseous ammonia from water.
After The separated ammonia vapor enters the condenser, where it cools and turns into a liquid state, releasing heat to the environment. Next, the liquid refrigerant evaporates in the evaporator, taking heat from the refrigeration chamber, after which it is again mixed with water. This cycle is repeated continuously as long as heat is supplied.
The key element here is diffuser, which ensures the movement of the mixture due to the difference in densities of gases and liquids. The absence of rubbing parts makes the system incredibly reliable, but requires strict adherence to installation rules, since the liquid in the circuit must move freely under the influence of gravity.
Advantages and disadvantages of technology
When choosing between compressor and absorption types of cooling, it is important to weigh the pros and cons, since each solution has its own niche of application. Absorption models are ideal for stationary placement in campsites or long road trips with overnight stays.
- ✅ Complete absence of noise and vibration, which allows the unit to be placed in a residential area.
- ✅ Possibility of operating on liquefied gas, which significantly saves car battery charge.
- ✅ Long service life due to the absence of mechanical moving parts.
- ✅ Versatility of connection (electricity 12/220V or gas).
However, the technology also has its limitations that must be taken into account before purchasing. Energy efficiency there are fewer such systems than compressor analogues, and the process of reaching operating mode takes longer time. In addition, sensitivity to inclines can be a problem when driving over rough terrain.
It is important to note that ammonia mixture is under pressure, and although modern safety systems minimize risks, damage to the tubes can lead to the leakage of toxic gas. Therefore, the mechanical strength of the case and the protection of the rear wall are critical.
⚠️ Attention: Absorption refrigerators cannot be tilted more than 15-20 degrees during operation. With a strong tilt, the liquid in the circuit can flow into the gas part, which will lead to blockage of the system and failure.
Comparison with compressor models
To clearly understand the difference, it is worth considering the technical characteristics of both types of devices. Compressor refrigerators, familiar to us in the kitchen, cool food faster and better maintain low temperatures even in hot weather. Absorption ones benefit from autonomy and silence.
Below is a table showing the main differences that will help you decide on the choice of equipment for specific tasks.
| Characteristics | Absorption type | Compressor type |
|---|---|---|
| Energy source | Gas, 12V, 220V | 12V, 220V |
| Noise level | 0 dB (silent) | 35-45 dB |
| Min. temperature | up to -6...-10°C | up to -18...-24°C |
| Tilt sensitivity | High | Low (up to 30-40°) |
| Service life | 15-20 years | 7-10 years |
If your goal is to deep freeze meat for several days in a hot climate, the compressor will do a better job. But if you just need to keep food cool while parked without access to electricity, Gas absorption will become an indispensable assistant.
Installation and ventilation requirements
Proper installation is the key to safe and efficient operation. Since when operating on gas or even when the heating element is very heated, heat is generated, and combustion products can also escape, the system requires high-quality ventilation duct. Usually these are two holes in the body of the motorhome: one at the bottom for the intake of fresh air, the other at the top for the removal of hot air.
The area of the ventilation holes must correspond to the power of the refrigerator indicated in the passport. Lack of air flow will lead to overheating of the unit, increased gas consumption and the risk of fire. Often, users ignore cleaning the lower ventilation duct, where dust and fluff accumulate, which critically disrupts draft.
☑️ Checking the installation of the refrigerator
Distance from the back of the refrigerator to the wall the niche should also be sufficient to ensure natural circulation. If you install the device yourself, be sure to use heat-resistant materials to finish the niche.
⚠️ Attention: It is strictly forbidden to use a gas absorption refrigerator while the car is moving. This creates a risk of gas leakage in a confined space and fire in the event of an accident.
Operation and typical problems
During use, owners may encounter a number of specific situations. For example, if the refrigerator stopped cooling after a long period of inactivity or transportation, the mixture may have separated. In such cases, sometimes “impact treatment” helps - lightly tapping the tubes, but it is better to contact a specialist to restart the system.
A frequent problem is the formation of an ice coat in the chamber. Absorption models do not have an automatic defrosting system, therefore manual defrosting is required regularly. Ignoring this process reduces the efficiency of heat transfer and increases energy consumption.
- ❄️ The appearance of a gas smell requires immediate ventilation and checking the connections with a soapy solution.
- ❄️ Poor cooling can be caused by clogged ventilation or malfunction of the heating element.
- ❄️ Clicks when operating on gas are normal for some models (valve operation), but constant crackling is a sign of a problem.
It is also worth remembering that the ammonia circuit is sensitive to the quality of energy. Voltage surges in the 220V network can damage the electronic control module or heater. Using a voltage stabilizer in campsites with an unstable network is a reasonable precaution.
What to do if the refrigerator does not turn on from gas?
Check the presence of gas in the cylinder, open the valve, bleed air from the system (press the ignition button several times without a spark), then try to ignite. If you hear a click, but the flame does not light up, the ignition battery may be low or the electrode is dirty.
Care and extending service life
To absorption refrigerator serve for decades, it is enough to follow simple rules of hygiene and operation. Wipe the door seals regularly, as loss of tightness forces the unit to work harder. Once a season, it is recommended to check the cleanliness of the burner (if the model is gas) from dust and cobwebs.
When storing for the winter, the doors of the device should be left slightly open to prevent the appearance of mold and unpleasant odors inside the chamber. If the refrigerator has not been used for a long time, before turning it on, let it stand in an upright position for several hours.
Frequently asked questions (FAQ)
Is it possible to transport an absorption refrigerator lying down?
Transportation in a horizontal position is extremely undesirable, since liquid from the circuit can flow into the pipe system where it shouldn't be. If this happens, before turning on the device must stand vertically for at least 24 hours to allow the liquid to drain into the evaporator.
Why does the refrigerator only cool on gas, but not from the mains?
Most likely, the electric heating element (TEN) has failed or the fuse in the 220V/12V circuit has blown. The gas part remains operational. Diagnostics with a multimeter and replacement of the burnt element are required.
What is the minimum temperature achieved in such refrigerators?
Usually absorption models are capable of cooling food to -5...-10 degrees Celsius relative to ambient temperature. Full deep freezing, as in home freezers (-18°C and below), should not be expected from them, especially in summer.
Is it safe to leave a working refrigerator unattended?
Modern models are equipped with a gas control system that shuts off the gas supply when the flame dies out. However, leaving gas-powered equipment for a long time unattended in a closed room is still not recommended for reasons of fire safety.