Idea Converting a freezer into a full-fledged refrigeration compartment often arises when old equipment breaks down or when it is necessary to expand the storage area for products that do not require deep freezing. Owners of old Soviet models or modern No Frost systems sometimes encounter compressor breakdown in the refrigerator compartment, while the freezer continues to work properly. In such a situation, a reasonable question arises: is it possible to make a camera designed for -18°C maintain a positive temperature of about +4°C? This is technically possible, but requires intervention in the electrical circuit and control system.
However, before taking up the tools, it is necessary to clearly understand the physical limitations of the process. Freezers are designed to operate in extremely low temperature conditions, which means the use of specific refrigerants, high-power compressors and specially thick insulating materials. Simply changing the settings of the thermostat will not give the desired result without a deep modernization of the hardware. The key point here is the understanding that you are actually creating a new device from an old one, changing its operating logic.
In this article we will analyze in detail the technical aspects of such a modification, we will touch upon the issues of replacing thermostats, improvements to the defrost and condensate control systems. You will learn why standard solutions may not work and what risks lurk when you independently intervene in the design. The main obstacle when remaking is the operating temperature range of the standard thermostat, which is physically unable to break the compressor power supply circuit at +4°C, since it is designed for triggering at much lower values. Be prepared for the fact that the process will require not only technical skills, but also an understanding of the basics of thermodynamics.
Analysis of design differences between freezer and refrigerator
The fundamental difference between the refrigerator and freezer compartments lies not only in the target temperature, but also in the design of the evaporator and the air circulation system. Freezers, especially type Direct Cool, use an evaporator that is cooled to very low temperatures, which leads to intense ice formation. If you try to simply raise the temperature, the system may no longer effectively remove moisture from the air, which will lead to the formation of a “fur coat” and increased humidity inside the chamber.
In addition, compressors installed on chest freezers or chambers are often classified as LBP (Low Back Pressure), while refrigerators work with HBP (High Back Pressure) or universal LBP/HBP compressors. The difference lies in the degree of compression of the refrigerant and the ability of the system to operate at higher boiling points of freon in the evaporator. Using the LBP compressor in refrigerator mode can lead to its overheating and rapid failure due to disruption of the lubrication and cooling conditions of the motor.
It is also important to take into account thermal insulation. The walls of the freezer are usually thicker, which is good for keeping things cold, but when converted into a refrigerator, this can play a cruel joke. When you open the door, warm air penetrating inside will condense on the cold walls more actively than in a conventional refrigerator if proper air circulation is not ensured. Thermal conductivity materials and the tightness of the seals must comply with the new operating conditions.
⚠️ Attention: Before starting any work, be sure disconnect the device from the power supply. Opening electrical circuits and working with refrigerant requires compliance with safety precautions. Improper handling of freon can lead to an explosive situation or frostbite.
It is also worth mentioning the differences in control systems. Modern freezers with electronics can block operation when the parameters are “incorrect” for them, considering them a sensor error. In such cases, remodeling becomes economically impractical and technically difficult.
Required Tools and Materials for Retrofit
To successfully complete a remodeling project, you will need a set of specialized tools and components. You should not rely on improvised means, since the accuracy of temperature settings is critical for the safety of products and the safety of equipment. The main element will be a new thermostat capable of operating in a range of positive temperatures.
You will need the following tools and materials:
- 🔧 A set of screwdrivers and wrenches for dismantling panels and removing old equipment.
- 🌡️ A new thermostat (for example, TAM-133 or an analogue with response range from +4°C to +12°C).
- 🧪 Solder, flux and gas torch (if you plan to replace the capillary tube of a mechanical type thermostat).
- 📏 Multimeter for checking circuits and contact integrity.
- 🧣 Thermal insulation materials (penofol or analogues) for additional sealing of gaps.
Particular attention should be paid to the choice thermostat. Standard freezing thermostats (for example, TAM-133 with a range of -24...-10°C) are not suitable, since they open the contacts at too low temperatures. You need a device that will turn off the compressor when the temperature inside the chamber reaches +4...+6°C. You may also need an extension for the capillary tube to correctly place the sensing element in the new control zone.
If your freezer is equipped with a system No Frost, the list of materials will expand. It may be necessary to modify the defrost heating element or timer so that the defrosting cycles correspond to the new temperature regime, where less ice is formed, but moisture condenses more actively.
Replacing and adjusting the thermostat
The most important part of the remodel is installing a new thermostat. It is this component that is responsible for maintaining the set temperature. In mechanical models, the process is as follows: first, the old regulator is dismantled and its capillary tube is carefully removed from the evaporator. Then a new device with a suitable temperature range is installed.
Installation of the sensing element (capillary tube) requires precision. It should fit snugly against the surface of the evaporator in an area where the temperature most accurately reflects the average temperature in the chamber. Often a special clamp or aluminum plate is used for this, which improves heat transfer. If the tube dangles in the air, the readings will be incorrect, and the compressor will idle or turn off too early.
In electronic control systems, the task becomes more complicated. Here, it may be necessary to resolder resistors on the control board or completely replace the control module with one compatible with the refrigeration mode. Electronics It is often strictly tied to factory algorithms, and it is impossible to programmatically change the operating logic without special equipment.
Nuances of setting up mechanical thermostats
Mechanical thermostats have an adjusting screw under the seal. Turning this screw allows you to shift the temperature range of the contacts. However, the offset range is limited (usually 2-3 degrees), so you won’t be able to radically change -18°C to +4°C just by adjusting the screw - you need to replace the thermostat itself.
After installing a new thermostat, it is necessary to carry out an initial calibration. Turn on the device and place an accurate thermometer inside. Let the camera run for a few hours. If the temperature drops below +2°C or rises above +8°C, re-adjustment or checking the tightness of the capillary tube fit is required. Calibration accuracy directly affects the shelf life of the products.
Refinement of the defrost system and control of condensation
When converting a freezer into a refrigerator, you will encounter a change in the physics of the processes inside the chamber. Freezers are designed to work with dry cold, where moisture freezes on the walls. In refrigeration mode (+4°C), the temperature difference between the warm air when the door is opened and the cold walls will lead to heavy condensation.
If your model is equipped with a system No Frost, the fans may continue to work too intensely, drying out the food, or, conversely, do not remove moisture effectively enough. In some cases, it is necessary to reduce the fan power or change the logic of their operation in order to ensure gentle circulation of air.
For drip defrost systems (crying evaporator), it is important to ensure that the drainage hole does not freeze. In freezer mode, it may not have time to thaw, and in refrigerator mode, it may become clogged with mucus due to higher bacterial activity. Regular cleaning of the drainage and, possibly, installation of additional heating of the drainage tray will become necessary measures. data-i="100">Check the operation of the defrost heating element (if any) heating element heating the drainage tray will be necessary measures.
☑️ Checking the defrost system
It is also worth paying attention to door seals. In refrigerator mode, they can operate in a more aggressive environment (humidity, temperature changes), which will accelerate their wear. If the seal does not fit tightly, condensation will form not only inside, but also outside, on the body.
Comparison of characteristics: Before and After alteration
So that you clearly understand what changes in the operation of the equipment should be expected, we have compiled a comparison table. It demonstrates how key operating parameters change after successful modernization.
| Parameter | Freezer (Standard) | After rework (Refrigerator) |
|---|---|---|
| Operating temperature | -18°C ... -24°C | +2°C ... +6°C |
| Humidity | Low (drying out) | High (risk of condensation) |
| Operation cycle | Long freezing cycles | Short maintenance cycles |
| Energy consumption | High (large delta T) | Medium/Low (smaller delta T) |
| Shelf life of products | Months (freezing) | Days/Weeks (cooling) |
As can be seen from the table, the most critical change is the humidity regime. If food has lost moisture in the freezer (sublimation), then in a converted refrigerator it can, on the contrary, become damp. This requires careful attention to the packaging of products. Energy consumption in refrigerator mode, as a rule, it decreases, since the compressor is turned on less often to maintain a positive temperature if the thermostat is set correctly.
Typical errors and safety measures
In progress remodeling enthusiasts often make mistakes that can lead to equipment breakdowns or product damage. One of the most common mistakes is ignoring the type of compressor. As mentioned earlier, LBP compressors are not designed to operate for long periods of time at the high suction pressure found in refrigerators. This can lead to overheating of the windings and jamming of the piston group.
Another mistake is incorrect installation of the thermostat. If the sensing tube is in contact with the metal wall of the housing rather than with the evaporator, the temperature reading will be distorted by external heat. This will cause the compressor to turn on too rarely, and the temperature in the chamber will rise to dangerous levels.
⚠️ Attention: Do not leave the converted device unattended during the first 24-48 hours of operation. Constantly monitor the temperature using an external thermometer. Any deviations from the specified range (+2...+8°C) require immediate stop and reconfiguration.
It is also worth remembering about the warranty. Any interference with the design and electrical circuit automatically cancels manufacturer's warranty. If the device is new or expensive, remodeling may not be economically justified compared to purchasing a specialized refrigerator.
Frequently asked questions (FAQ)
Is it possible to convert a freezer back into a freezer?
Yes, this is possible, but it will require replacing the thermostat with a freezer one (with a range of up to -24°C) and possibly adjustment of the defrost system. The main thing is to make sure that the compressor and insulation have not been damaged during previous operation in refrigerator mode.
How long does the remodeling process take?
For an experienced technician with ready-made spare parts, replacing a thermostat takes about 1-2 hours. However, complete setup, testing of temperature conditions and stabilization of the system may take from 12 to 24 hours.
Will a converted chamber be more economical than a conventional freezer?
In refrigerator mode (maintaining +4°C), electricity consumption is usually lower than in deep-freeze mode (-18°C), since the temperature difference with the environment less and the compressor works less intensively. However, the efficiency of a particular compressor in a non-native mode may be lower.
What products are best stored in such a chamber?
Vegetables, fruits, dairy products and drinks are perfectly stored in a converted chamber. However, due to possible fluctuations in humidity (if the condensation problem has not been solved), it is not recommended to store products there in open containers or those that are sensitive to dampness (for example, dry cereals without sealed packaging).
Is it necessary to change the refrigerant during the alteration?
No, replacing the refrigerant (freon) during the alteration Freezing into a refrigerator is not required and is not recommended. The system is filled with gas at the design pressure. Changing the gas type will disrupt the entire thermodynamic circuit and may lead to compressor failure.