Modern household refrigerators are complex engineering systems, where each element performs a critical function. One of the key components ensuring the safety of products is crying evaporator. This term often appears in technical documentation and model descriptions, raising questions among users who are not familiar with the intricacies of thermodynamics.
Unlike systems that use forced air circulation, a weeping system relies on natural convection. This makes the design simpler, but requires an understanding of the physical processes of moisture condensation. This is where the internal volume of the chamber is cooled and excess moisture is removed from the air.
Understanding how it works Direct Cool (as this technology is often called) will help you operate the equipment correctly and notice the first signs of malfunction in time. In this article we will analyze in detail the device, operating principle and maintenance features of this unit.
Principle of operation and physics of the process
The basis of the work is a cyclic change in the surface temperature of the rear wall of the refrigeration chamber. When the compressor turns on, refrigerant circulates through pipes built into or located on the rear panel. At this moment, the surface temperature drops sharply, reaching negative values.
The moisture contained in the air inside the chamber, upon contact with the cold wall, condenses and turns into frost or an ice crust. This process is necessary to dry the air, which prevents food spoilage and mold. Heat transfer occurs most efficiently precisely due to the formation of this layer of ice.
When the thermostat detects that the set temperature has been reached, the compressor turns off. The back wall begins to heat up and the accumulated ice melts. Drops of moisture flow down the groove into a special hole, from where, through a drainage tube, they enter the container above the compressor, where they evaporate.
⚠️ Attention: If you notice that water does not go into the drainage hole, but accumulates at the bottom of the refrigerator, this is the first sign of a blockage. Do not try to clean it with sharp metal objects - there is a high risk of damaging the cooling system.
The key point is that evaporator in such models it is often hidden behind a plastic panel or is its internal part. Freezing and thawing cycles are repeated automatically several times a day, ensuring a stable microclimate.
Design features of the evaporator
In refrigerators with a weeping system, the evaporator may have a different design. In budget models, this is often an aluminum tube glued to the back wall of the camera. More expensive options use a sheet-rolled evaporator, where the tube is pressed between two sheets of metal, which improves heat transfer.
The location of the element also affects operating efficiency. The classic option is the back wall, but in some models the evaporator can be located on top or on the sides of the chamber. This depends on the volume of the refrigerator and the refrigerant used.
- 🧊 Aluminum panels: light and cheap, but sensitive to mechanical damage and corrosion.
- ❄️ Steel sheet-rolling: more reliable, hold the temperature better, but are heavier.
- 💧 Tubular coils: often found in older models, where the tube is simply attached to the wall with clamps.
Materials are selected taking into account their thermal conductivity and resistance to aggressive environments. Aluminum and stainless steel are the most common options. It is important to understand that any deformation of the rear wall can lead to compression of the evaporator tubes and disruption of refrigerant circulation.
Differences from the No Frost system
Users often confuse the weeping system with the No Frost technology, although the fundamental difference between them is huge. In the No Frost system, the evaporator is located hidden, usually in the freezer or behind a partition, and cooling occurs due to forced air circulation by a fan.
In a “crying” refrigerator, the air moves naturally: cold air moves down, warm air rises up. This means that the temperature in different areas of the chamber can vary by several degrees. In the system No Frost the temperature equalizes faster and more evenly.
Another important difference is the need to manually defrost the freezer. In a weeping system, the refrigerator compartment thaws itself, and the freezer (if it is separate) requires periodic defrosting by the owner. In No Frost, you don’t need to defrost anything.
| Characteristics | Crying system (Direct Cool) | No Frost |
|---|---|---|
| Defrost mechanism | Automatic (refrigerator compartment only) | Automatic (full) |
| Humidity | High (products dry more slowly) | Low (products may air out) |
| Energy consumption | Lower (no fan and defrost heating element) | Higher |
| Useful volume | Maximum (no protruding elements) | Less due to the circulation system |
The choice between these systems depends on your preferences. If natural humidity is important to you for storing fruits and vegetables, a weeping evaporator will be the best choice. If the priority is not having to monitor the ice, it’s worth considering alternatives.
Typical faults and their symptoms
Despite the simplicity of the design, the system can fail. Most often, problems are associated not with the evaporator itself, but with accompanying elements. However, knowing the symptoms will help you quickly diagnose the problem. One of the common phenomena is the formation of a “coat” - an excessive layer of ice that does not melt.
This may indicate a malfunction thermostat or the defrost sensor. If the compressor does not receive a signal to stop, the evaporator continues to freeze and the water does not have time to drain. As a result, ice blocks the moisture removal channels.
Another common problem is a refrigerant leak. If you see that the back wall has stopped cooling or is only partially cooling (for example, only in the corner), this is an alarming sign. Traces of oil or swelling of paint are often visible at the leak site.
- 🔊 Extraordinary noise: Gurgling or hissing may indicate improper circulation of freon.
- 💧 Puddle inside: water on the floor of the refrigerator indicates freezing of the drainage hole.
- 🌡️ Unstable temperature: products spoil faster than usual or, conversely, freeze at the back wall.
⚠️ Attention: If you smell gas or chemicals, immediately unplug the refrigerator and ventilate the room. This may indicate a serious leak of refrigerant, which in high concentrations is hazardous to health.
Timely detection of these signs allows you to avoid more serious breakdowns, such as compressor combustion due to operation in extreme mode.
Operation rules and care
To the crying evaporator served for a long time, you must follow simple operating rules. First of all, this concerns product placement. Don't place food close to the back wall. The minimum gap should be 2-3 centimeters.
Why is this important? If food touches a cold surface, it may freeze. When trying to tear them off, it is easy to damage the thin wall of the evaporator. In addition, this disrupts the natural circulation of air, and the refrigerator begins to work with increased load.
☑️ Monthly maintenance of the refrigerator
Regular cleaning also plays a role. Periodically (every 3-4 months) it is recommended to defrost the refrigerator completely, even if it is equipped with an automatic defrosting system. This will help clean the drainage channel and remove accumulated dirt.
For cleaning, use only special products or a weak soda solution. Aggressive chemistry can damage plastic elements and seals, as well as cause corrosion of metal parts of the evaporator.
Replacement and repair process
If the evaporator fails (there is a leak or mechanical damage), replacing it is a complex procedure. In most modern models, the evaporator is foamed in the refrigerator body. This means that access to it often requires opening the case or carefully bending the plastic, which can lead to loss of presentation.
Repair includes several stages: searching for leaks, soldering a new evaporator (often craftsmen install a mounted one), evacuation of the system and refueling refrigerant. It is impossible to carry out this work independently without special tools.
⚠️ Attention: A mounted evaporator installed instead of a built-in one can reduce the efficiency of the refrigerator and increase energy consumption. Try to find an original spare part or a high-quality analogue.
The cost of repairs often depends on the type of evaporator and the difficulty of accessing it. In some cases, it is more economically feasible to purchase a new refrigerator than to restore an old one with a foamed evaporator.
Why can’t you just solder a hole?
The soldering point on aluminum (the main material of evaporators) oxidizes in a matter of minutes. Without special flux and skills, the seam will leak again after a few months. In addition, you need to accurately calculate the amount of freon, otherwise the compressor will burn out.
Impact on food safety
One of the main features of a weeping evaporator is maintaining a high level of humidity. These are ideal conditions for vegetables, fruits, herbs and cheeses. They do not lose moisture as quickly as in blower systems, remaining fresh and elastic longer.
However, for products that require dry storage (for example, some types of sausages, dry cheeses in open packaging), high humidity may be undesirable. In such cases, it is recommended to use airtight containers.
Temperature fluctuations in different zones of the chamber require proper distribution of products. It is always colder at the back wall, where the evaporator is located. It is better to place products there that require strong cooling, but not freezing.
Understanding these nuances will allow you to make the most of the capabilities of your refrigerator and minimize spoilage products.
Frequently asked questions (FAQ)
Why does ice form on the back wall of the refrigerator?
The formation of ice (frost) on the back wall is a normal operating process for a weeping system. Moisture in the air condenses and freezes when the compressor operates. When the compressor stops, this ice should melt and flow down. If the ice does not melt and forms a fur coat, check the tightness of the door closure and the serviceability of the thermostat.
How often should you defrost a refrigerator with a crying evaporator?
Although the refrigerator compartment is defrosted automatically, the freezer compartment (if it is not No Frost) must be defrosted manually 1-2 times a year. It is also recommended to completely defrost the entire refrigerator with washing 1-2 times a year for hygiene and cleaning the drainage.
Is it possible to speed up the defrosting of the evaporator with a hairdryer?
It is strictly not recommended to use a hairdryer, especially hot air. Sudden temperature changes can lead to cracks in the plastic housing and damage to the evaporator tubes. It is better to wait for natural thawing or use containers with warm (not hot) water placed on shelves.
What to do if the drainage hole is frozen?
If the water is at the bottom of the chamber, the drainage is most likely frozen. Take a soft rubber bulb filled with warm water and gently pour it into the hole. You can use a special cleaning brush (often included), but be careful not to puncture the tube.
Does the fullness of the refrigerator affect the operation of the evaporator?
Yes, it does. A refrigerator that is too densely packed interferes with natural air circulation. Cold air should freely wash the food and the back wall. Leave small gaps between products for effective heat exchange.