Many owners of single-compartment refrigerators or “box-in-box” models are faced with a lack of space for deep-freezing food. The question often arises whether it is possible to independently convert an existing unit in order to obtain a full-fledged freezer. This is theoretically possible, but the process requires in-depth knowledge of thermodynamics and refrigeration. Simply adding a shelf will not solve the problem, since temperature conditions must be maintained at a level of minus 18 degrees Celsius, which is uncharacteristic for a conventional refrigerator compartment.
There are several ways to solve the problem: from purchasing specialized equipment to complex technical modernization. It is important to understand that interfering refrigerant circuit without the appropriate license and tools often leads to damage to equipment. In this article, we will examine in detail real ways to increase the volume of freezing and explain why some methods are considered dangerous or ineffective.
Before proceeding with any actions, it is necessary to assess the technical condition of your unit. If the refrigerator is old, its insulation may have lost its properties, and any attempts to strengthen the freezer will only lead to increased energy consumption. Modern models They often have more complex control systems that will not allow you to simply change the operating parameters without reflashing the controller.
Technical limitations of single-chamber refrigerators
Single-chamber refrigerators are designed to maintain a temperature of about +4..+6 degrees Celsius. The evaporator in them is usually located at the top or behind the back wall, and its power is not enough to deep freeze a large volume of food. An attempt to load such a compartment with a large amount of meat or vegetables will lead to the fact that compressor it will work continuously, trying to compensate for heat inflows, which will quickly disable it.
The main problem is the difference in thermal loads. The freezer compartment requires rapid heat removal when loading warm foods, while the refrigerator compartment operates in a more gentle mode. If you try to fence off part of the space and make a freezer out of it, you will violate the natural air circulation. This will lead to the formation of ice jams and uneven cooling.
⚠️ Attention: Sealing part of the refrigerator compartment to create a separate freezing zone without installing an additional evaporator will lead to overheating of the compressor and a possible fire due to impaired heat exchange.
In addition, such models often use one thermostat, which responds to the temperature in the main chamber. Even if you can locally lower the temperature in a makeshift freezer, the sensor at the top will “think” that the refrigerator is too cold and will turn off the compressor. As a result, the food in the lower part will remain defrosted, and in the upper part will begin to spoil.
Method of installing an additional evaporator
The most technically competent, but complex way to turn part of the refrigerator into a freezer is to install an additional plate evaporator. This method is used by professional craftsmen when repairing and modernizing equipment. The essence is to introduce an additional heat exchange surface into the system, which will cool the allocated volume.
To implement this project you will need:
- 🔧 Find a plate evaporator of suitable size (often taken from old refrigerators or buy universal ones).
- 🔧 Have the skills to work with copper pipes, solder and refrigerant.
- 🔧 Have a vacuum pump and a pressure gauge station for charging the system.
- 🔧 Be able to calculate the thermal load and select the length of the capillary tubes.
After installing the new heat exchanger, you must correctly position the thermostat. The temperature sensor must be monitored specifically in the area of the new freezer. Sometimes you have to install a second thermostat or replace the existing one with a model with a different response range. Without this work cycle the compressor will be damaged, and the products will either freeze or spoil.
☑️ Tools for modernization
Use of the Peltier effect for a mini-freezer
An alternative to complex reworking of the freon circuit can be the use of thermoelectric modules, known as elements Peltier. These devices are capable of creating a temperature difference when an electric current passes. Although their efficiency (efficiency) is lower than that of compressor systems, this may be enough to create a small freezer compartment with a volume of 10-20 liters.
To assemble such a design you will need a powerful Peltier module (for example, series TEC1-12706 or more powerful analogues), radiators on both sides and an effective ventilation system. The hot side must be intensively cooled, otherwise the module will burn out. The cold side will cool the internal volume of the insulated box, which can be placed inside the main refrigerator or made separate.
The main advantage of this method is the absence of moving parts and refrigerant. However, there are also significant disadvantages:
- ❄️ Low performance: freezing a large volume of food will take a very long time.
- ❄️ High energy consumption relative to the cold received.
- ❄️ Dependence on a stable supply voltage.
- ❄️ Formation of condensation, requiring moisture removal.
Can Peltier modules be used for ice?
Yes, but only in small volumes. To produce ice cubes, you will need a powerful radiator and a fan on the hot side, otherwise the efficiency will drop to zero and the water will not freeze.
Comparison of upgrade methods
The choice of upgrade method depends on your technical skills and budget. Below is a table that will help compare the main characteristics of the considered methods. It shows that there are no “simple” solutions, and each requires investment.
| Method | Complexity | Cost | Efficiency | Risk breakdowns |
|---|---|---|---|---|
| Add. evaporator | High | Medium | High | High |
| Peltier module | Average | Low | Low | Average |
| Purchase of a chest | Absent | High | Maximum | Absent |
| Compartment separation | Low | Low | Zero | Critical |
As can be seen from the table, an attempt to simply divide the compartment (separation method) has a critical risk of breakdown and zero effectiveness in terms of creating a real freezer. This is a dead-end path, which is often chosen by inexperienced users wanting to save money.
The most reliable, albeit costly, way is to purchase a separate chest freezer. This will save you from the risk of damaging your main refrigerator and ensure that your food is properly stored. However, if you are an enthusiast and want to experiment, the method of installing an evaporator gives a professional result.
Problems with the thermostat and sensors
One of the main difficulties when remodeling is temperature control. Standard thermostat in the refrigerator is set to a range from 0 to +10 degrees. Even if you install a powerful evaporator, the thermostat will turn off the compressor as soon as it becomes +2 degrees in the main chamber, preventing the freezer from reaching the -18 mode.
The solution may be to install an additional thermostat that will control the compressor in parallel with the main one or instead of it. To do this you need:
- Remove the old sensor.
- Install a new thermostat with a range suitable for the freezer (for example, from -10 to -24 degrees).
- Correctly place the capillary tube of the sensor in the area of the new freezer.
⚠️ Attention: In electronically controlled refrigerators, an attempt to mechanically replace sensors can lead to a system error and block the operation of the entire unit. Diagnostics through the service mode is required.
It is also worth considering the inertia of the system. A sensor placed in the freezer will respond to temperature changes faster than a sensor in the main compartment. This can lead to frequent switching on and off of the compressor, which will shorten its life. It is necessary to correctly select heat capacity cooling zones or adjust the thermostat hysteresis, if possible.
Energy efficiency and insulation
Any attempt to create a freezer where it is not provided by the manufacturer leads to an increase in heat gain. The walls of a regular refrigerator have a thinner layer of insulation compared to full-fledged freezers. This means that even when the compressor is running, some of the cold will go outside, and heat will penetrate inside.
To minimize losses it is necessary:
- 📉 Check the integrity of the rubber seals on the door.
- 📉 Make sure that the new freezer compartment has additional thermal insulation.
- 📉 Do not open the door more often than necessary.
- 📉 Keep the condenser (grid at the back) clean, as with increased load it heats up more.
If you notice that the side walls of the refrigerator have become excessively hot, and inside the a lot of ice, this is a sign of overload. In this case, you should immediately stop experiments and return the system to its original state, otherwise motor-compressor it will burn out due to thermal breakdown of the winding insulation.
Frequently asked questions (FAQ)
Is it possible to simply put dry ice in the refrigerator?
The use of dry ice is possible for short-term temperature maintenance during a power outage, but not for permanent operation. The temperature of dry ice (-78°C) is too cold for standard plastic refrigerator parts and they may become brittle and crack. In addition, during sublimation, carbon dioxide is released, which can be dangerous in a confined space.
Why does the water in the lower shelves not freeze in a single-chamber refrigerator?
In single-chamber models, cold air is heavier than warm air and falls down, but the evaporator is at the top. The airflow design is not designed to create sub-zero temperatures at the bottom. There the temperature is maintained at about +2..+4°C, which is ideal for storing vegetables, but not enough for freezing water.
Is it dangerous to fill the refrigerator with freon yourself?
Yes, it is dangerous. Freons are under pressure, and some types (for example, R600a isobutane) are explosive when concentrated in air. In addition, refilling requires precise adherence to the dosage (up to a gram) and the use of a vacuum pump. An attempt to refuel “by eye” will lead to compressor breakdown.
Is it worth buying a used freezer instead of remodeling?
Absolutely, yes. A used freezer (chest or cabinet) will work efficiently, have proper insulation and a guaranteed service life. Remodeling a refrigerator is a lottery with a high risk of losing both the main unit and time. The cost of used equipment is often comparable to the cost of materials and tools for modernization.