How to make one from two refrigerators: 5 working methods with instructions

Combining two refrigerators into a single system is a task that arises for owners cafes, small shops or households with limited space. Most often, this is true when one unit fails and the second one is worn out, or when it is necessary to create zones with different temperature conditions (for example, for meat and vegetables). But before you take up the tools, it is important to understand: not all refrigerators can be physically combined, and some methods require serious modifications to the electrical and thermal insulation.

In this article we will analyze 5 proven methods - from simple connection to one power source to full integration of cameras with a common compressor. You will learn which models Samsung, Indesit or Atlant are best modified, how to avoid short circuits when connected in parallel, and why combining freezer and refrigerator compartments can save up to 30% of electricity. We will also provide cost calculation alterations and a table of brand compatibility.

⚠️ Critical warning: Any manipulations with freon circuits or electricity require a refrigeration certificate. Incorrect connection of the pipes can lead to leakage of freon R-134a or R-600a (explosive at concentrations above 31 g/m³) or damage to the compressor. If you are not confident in your skills, contact a specialist certified in FNP No. 538 (rules for working with refrigerants).

1. Method No. 1: Parallel connection to one compressor

This is the most complex, but also the most effective method that allows combine two chambers into a single cooling system. Operating principle: one compressor circulates freon through two circuits, regulating the temperature in each zone separately. This approach is used in industrial refrigerators, but it can be adapted for household models only if three conditions are met:

✅ Both refrigerators must be of the same brand and approximately the same year of manufacture (for example, LG GA-B489 i LG GA-B489S). Different brands use incompatible refrigerants and oil for compressors

✅ The total volume of the chambers should not exceed 400 liters - otherwise the compressor will wear out.

✅ One of the refrigerators must have a working compressor with a power reserve (see parameter BTU/h in the passport).

For implementation you will need:

• 🔧 Median tubes with a diameter of 6–8 mm (the length depends on the distance between the refrigerators).
• 🔥 Torch for soldering with solder (for example, Castolin 192 for copper tubes).
• 📏 Manometer to check the pressure in the system (norm: 0.5–1.5 bar at rest).
• 🛠️ Vacuum pump to remove moisture before charging with freon.

Drain freon from both refrigerators (only certified equipment)|

Check the integrity of the seals on the doors|

Install check valves on each circuit|

Connect a pressure gauge to the service port|

Solder the tubes using argon welding (not soldering iron!)

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⚠️ Attention: If freon was used in one of the refrigerators R-12 (banned since 2020), it cannot be mixed with modern refrigerants (R-134a, R-600a). A complete oil change in the compressor and flushing of the system will be required.

2. Method No. 2: Uniting through a common thermostat

A simpler option is to connect both refrigerators to one thermostat, which will control their operation synchronously. This method is suitable if:

- You do not need different temperatures in the chambers (for example, both compartments will work as freezers).

- Refrigerators are nearby, and you can stretch the control cable between them.

For implementation buy programmable thermostat (for example, STC-1000 or Xiaomi Mijia Temperature & Humidity Monitor) and connect it according to the scheme:

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⚠️ Attention: If the total power of the compressors exceeds 2 kW, the thermostat may overheat. In this case, add intermediate relay (for example, Finder 40.52).

Two household ones (for example, Atlant and Biryusa)|

Household + industrial|

Two freezers|

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3. Method No. 3: Creating a single body with thermal insulation

If the refrigerators are back to back, you can combine them physicallyby removing partitions and increasing thermal insulation. This method is popular among owners of small shops where they need to increase the useful volume without purchasing new equipment.

Step-by-step instructions:

1. Disconnect both refrigerators from the network for 24 hours (for defrosting and evaporation freon).
2. Remove the doors and internal shelves. In models Samsung RB or Liebherr CN the shelves are fastened with latches - they can be removed without tools.
3. Cut out the partition between the chambers with a grinder (if the refrigerators are close together, use a disc). metal 1.6 mm thick.
4. Install an additional layer of insulation (polyurethane foam or Penofol 20 mm thick) at the joints.
5. Secure a new common door or leave two separate ones, but add magnetic seals.

💡 Tip: To seal the seams, use silicone sealant Dow Corning 7091 —it can withstand temperatures from −60°C to +180°C and does not crack over time.

If you do not need to physically combine the chambers, you can repurpose one refrigerator as a freezerand leave the second for cooling. This is true for models with a system Full No Frost, where the temperature is controlled electronically.

How to set up:

• 🔄 Set the temperature in the first refrigerator −18°C ("Super Freeze" mode).
• 🌡️ Set the temperature in the second refrigerator +4°C (optimal for vegetables and dairy products).
• 🔌 Connect both units via smart socket (for example, TP-Link HS100) to control the power remotely.