Homemade evaporator for a refrigerator: step-by-step instructions with diagrams and tips

The evaporator is a key element of the refrigeration system, responsible for absorbing heat from the interior of the chamber. When a standard evaporator fails (due to corrosion, mechanical damage or blockages), many owners are faced with a dilemma: buy a new part for 3-8 thousand rubles or try to restore functionality themselves. This article will help you figure out how to make an evaporator for a refrigerator at home, without having professional equipment.

We will look at two main approaches: repairing a damaged evaporator (soldering, sealing) and making a new one from scrap materials (copper tubes, aluminum plates). We will pay special attention safety measures —working with refrigerant and high pressure requires strict adherence to the rules. You will also find a comparison table of materials, a checklist of tools and answers to frequently asked questions about troubleshooting.

Before you start work, Please note: a homemade evaporator will not always be as effective as a factory one. However, in cases where the original spare part is not available (for example, for refrigerators Stinol 103 or Atlant XM-4021 over 15 years old), this may be a temporary or budget solution. If you are not confident in your skills, it is better to contact a specialist - errors when soldering or refilling freon can lead to complete failure of the compressor and refrigerant leakage.

1. Signs of a malfunctioning evaporator: how to diagnose the problem

Before making a new evaporator, make sure that this is the problem. The main symptoms of a malfunction:

• 🔴 The refrigerator runs non-stop, but does not cool (the compressor is humming, but the temperature in the chamber is above +10°C).
• ❄️ A thick layer of ice forms on the back wall of the chamber, which does not melt even when defrosting.
• 💧 There are puddles of water under the refrigerator, although the drainage system is clean.
• 🔊 Extraneous sounds (gurgling, hissing) from under the rear panel are a sign of a freon leak.
• 📉 An error flashes on the display (if any) E1, F2 or a similar one (check in the instructions for the model).

For an accurate diagnosis, follow these steps:

1. Unplug the refrigerator and defrost it for 12-24 hours.
2. Remove the back panel in the freezer (usually secured with screws or latches).
3. Inspect the evaporator for subject:
   • 🔍 Cracks or punctures in the tubes (often caused by corrosion or mechanical damage when defrosting with a knife).
   • 🧊 A thick layer of ice between the ribs (indicates a clogged capillary tube or a malfunction of the thermostat).
   • 🟢 Oxidation on copper tubes (green coating is a sign of freon leakage).

Check the integrity of the thermal insulation around the evaporator. If it is wet or deformed, this may indicate a prolonged leak.

⚠️ Attention: If you find green spots on the copper tubes or hear hissing when the compressor is running, do not turn on the refrigerator these are signs of a freon leak. The refrigerant is toxic and can cause poisoning if inhaled in a closed room.

If the evaporator is externally intact, but the refrigerator does not cool, the problem may lie in:

• 🔧 Clogged capillary tube (purge required nitrogen).
• 🔋 Compressor malfunctions (check the winding resistance with a multimeter).
• 🌡️ Breakdown of the thermostat or temperature sensor.

2. Materials for making an evaporator: what can be used

For a homemade evaporator, materials with high thermal conductivity are suitable. Optimal options:

For soldering you will need:

• 🔥 Gas torch or powerful soldering iron (100–150 W).
• 🧪 Flux for copper/aluminum (for example, F-38N or Castolin 1905).
• 🛠️ Solder (for copper - POS-61, for aluminum - TsOP-40).
• 🧤 Protective gloves and glasses (required when working with the burner!).

If you are using tubes from an old refrigerator, they need to be cleaned of remnants of freon and oil. To do this:

1. Rinse the tubes with solvent. (for example, white spirit).
2. Blow with compressed air (you can use a car compressor).
3. Check for leaks by immersing in water and applying air under a pressure of 2-3 atm (there should be no bubbles).

⚠️ Attention: Do not use for the evaporator galvanized pipes or. iron - they quickly rust when in contact with condensate, which will lead to repeated leakage of freon. Also avoid plastic parts: they do not withstand low temperatures and refrigerant pressure.

3. Drawings and diagrams of the evaporator: how to calculate the dimensions

The dimensions of the evaporator depend on volume of the fridge compartment i compressor powerSuitable for household refrigerators (150–300 l). the following parameters:

• 📏 Surface area: 0.3–0.5 m² (the more, the more efficient the heat exchange, but do not overdo it - excess area will increase the load on the compressor).
• 🌀 Tube diameter: 6–8 mm for the main circuit, 4–6 mm for the capillary tube.
• 🔄 Pitch between turns: 20–30 mm (winding too tightly will impair circulation air).
• 📐 Shape: coil (for the freezer) or flat panel (for the refrigerator).

Example drawing for a refrigerator with a volume of 200 l:

|                          |
|   ==================== |  ← Upper part of the camera
|   =                  =   |
|   = COIL: = |  ← 8–10 turns of tube Ø6 mm
|   = pitch 25 mm = |
|   =                  =   |
|   ====================   |
|                          |

To make a coil:

1. Wind the copper tube onto a cylindrical template (for example, a bucket or pipe with a diameter of 20–30 cm).
2. Secure the coils with plastic ties or aluminum tape, leaving a gap 2-3 mm between them for air circulation.
3. Solder the inlet and outlet tubes to the coil (the length depends on the distance to the compressor).

If you are making a flat evaporator (for a refrigerator), use aluminum plates as ribs. Design example:

• 🔹 Base: aluminum sheet 30×40 cm, thickness 1.5 mm.
• 🔹 Tubes: copper, diameter 6 mm, soldered in a zigzag with a pitch of 30 mm.
• 🔹 Fastening: the plates are pressed to the tubes with clamps or soldered (aluminum requires a special flux).

How to calculate the length of the tube for the evaporator?

For a refrigerator with a volume of 200 liters, you will need ~5–7 meters of Ø6 mm tube.

Formula approximate: Length (m) = Chamber volume (l) × 0.03.

For example, for 250 l: 250 × 0.03 = 7.5 m. Please note that a tube that is too long will increase resistance to freon flow, and a short tube will reduce efficiency cooling.

4. Step-by-step instructions: how to make an evaporator from copper tubes

Let's consider the process using the example of a coil for the freezer compartment of a refrigerator Atlant.

Disconnect the refrigerator from the network and defrost|Remove the back panel of the freezer|Prepare tools (soldering iron, flux, solder)|Wear protective gloves and goggles

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Step 1: Dismantling the old evaporator

Carefully disconnect the evaporator tubes from the system:

1. Mark with a marker which tube goes where (input/output) so as not to be confused when returning assembly.
2. Cut the tubes with a pipe cutter at a distance of 10–15 cm from the evaporator.
3. Remove the old evaporator, clean the installation site from ice and dirt.

Step 2: Making a new coil

Take a copper tube with a diameter of 6 mm and a length of 6-7 meters:

1. Wind it around a cylinder (for example, a 5-liter bottle of water) in increments of 25 mm. The coils should lie flat, without distortions.
2. Secure the structure with aluminum tape or plastic ties.
3. Solder straight sections of tubes to the ends of the coil (the length depends on the distance to the compressor).

For soldering:

• 🔥 Heat the joint with a torch.
• 🧪 Apply flux with a brush.
• 🛠️ Apply solder - it should spread evenly over the seam.
• 🧊 Let it cool naturally (not cool with water!).

Step 3: Installation and connection

Install the new evaporator in place of the old one:

1. Fix the coil on the back wall of the chamber using aluminum tape or plastic clips.
2. Connect the tubes to the system, using copper adapters (solder them with a gas soldering iron).
3. Check the tightness of the connections with a soap solution (apply with a brush to the seams and apply air under a pressure of 2-3 atm - bubbles will indicate a leak).

Step 4: Evacuate and charge with freon

This is the most critical stage. You will need:

• 🔧 Vacuum pump (can be rented at a service center).
• 🧪 Freon cylinder (type depends on the refrigerator model, usually R-134a or R-600a).
• 📶 Gauge manifold.

Procedure:

1. Connect the manifold to the service port of the compressor.
2. Turn on the vacuum pump for 15–20 minutes to remove moisture and air from the system.
3. Add small amounts of freon in portions, controlling the pressure using a pressure gauge (for R-134a working pressure ~0.5–1.5 atm on the low pressure side).
4. Turn on the refrigerator and check the temperature in the chamber after 2-3 hours.

⚠️ Attention: If you do not have experience working with freon do not refill the system yourself. Errors in dosage or refrigerant leakage can lead to compressor failure. In this case, it is better to invite a specialist for final filling.

5. Alternative methods: repairing the old evaporator

If the damage to the evaporator is minor (small cracks or punctures), it can be repaired without completely replacing it. method:

Method 1: Soldering cracks

Suitable for copper evaporators with cracks up to 5 mm long.

1. Clean the damaged area with sandpaper until shiny.
2. Apply flux and solder the crack using gas burner.
3. After soldering, check the tightness with compressed air.

For aluminum evaporators, use special solder (for example, Castolin 192FBK) and flux for aluminum.

Method 2: Sealing epoxy resin

Temporary solution for small punctures (not suitable for pressure tubes!).

1. Clean and degrease the puncture site with acetone.
2. Apply two-component epoxy resin (for example, EDP) 2-3 layers.
3. Allow to dry 24 hours before turning on the refrigerator.

This method is only suitable for external damage to the evaporator of the refrigerator compartment (not the freezer!). For freezers only. soldering or replacement.

Method 3: Installing an additional radiator

If the evaporator works, but is not efficient enough (for example, due to clogging of the fins with ice), you can install an additional heat exchanger:

• 🔹 Buy a ready-made aluminum radiator (for example, from a computer processor).
• 🔹 Attach it to the back wall of the chamber next to the main evaporator.
• 🔹 Connect a 12 V fan to it (you can take it from the computer power supply) for forced circulation air.

Such a “booster” will increase the cooling efficiency by 15–20%, but will not replace a full repair of the evaporator.

6. Common mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes when making an evaporator:

Another typical problem is incorrect installation of the evaporator. For example, if the coil touches the walls of the chamber, this can lead to:

• 🔹 Freezing of the door seal (it will stop closing tightly).
• 🔹 Overheating of the compressor due to insufficient heat exchange.
• 🔹 The appearance of condensation on the external walls of the refrigerator.

To avoid this, follow the following installation rules:

• 📏 The minimum distance from the evaporator to the chamber walls is 20 mm.
• 🔄 The tubes should not intersect or touch each other.
• 🛠️ All fastenings must be made of non-flammable materials (aluminum, stainless steel).

7. Safety measures: working with freon and high pressure

Freon and other refrigerants are colorless and odorless, but if leaked in a closed area, they may cause suffocation. Basic safety rules:

• 🚪 Work in a well-ventilated area or outdoors.
• 😷 Use a respirator (for example, 3M 6001) when soldering and refilling.
• 🔥 Keep a fire extinguisher on hand (soldering work is a source of open flame).
• 🧤 Wear nitrile gloves - freon corrodes the skin with prolonged contact.

When refilling freon:

• 📶 Never fill the cylinder "blindly" - use a pressure gauge.
• 🚫 Do not smoke or use open fire near the cylinder.
• 🔌 Disconnect the refrigerator from the network before connecting the manifold.

If you feel dizziness or nausea while working:

1. Leave the room immediately.
2. Ventilate it for 15-20 minutes.
3. If symptoms persist, consult a doctor (freon can cause a chemical burn to the lungs).

⚠️ Attention: Refrigerant R-600a (isobutane), used in modern refrigerators explosive at a concentration in the air of more than 1.3%. Do not fill the system with it in a room with poor ventilation!

8. FAQ: Frequently asked questions about making an evaporator

❓ Is it possible to make an evaporator from aluminum cans?

Theoretically, yes, but this is an extremely ineffective solution. The aluminum of the cans is too thin (0.1 mm) and will not withstand freon pressure. In addition, soldering such cans is almost impossible without special equipment. It is better to use aluminum sheets 1–2 mm thick or copper tubes.

❓ How much does it cost to make an evaporator in a service center?

The cost depends on the refrigerator model and region:

• 🔹 Replacing the evaporator in refrigerators Atlant/Stinol: 4,000–6,000 rubles
• 🔹 For Samsung/LG (imported models): 6,000–10,000 RUB
• 🔹 Repair (soldering cracks): 2,000–3,500 RUB.

A homemade evaporator will cost 1,000–2,500 RUB. (materials), but does not guarantee durability.

❓ Which freon should I use for a homemade evaporator?

The type of freon depends on the compressor model:

• 🔹 R-134a —the most common, suitable for most refrigerators from 1990–2010.
• 🔹 R-600a (isobutane) - used in modern models (for example, Liebert, Beko). Explosive!
• 🔹 R-12 - outdated, prohibited for use in new systems.

The type of refrigerant is indicated on the compressor sticker (for example, Compressor: Danfoss NL6, Gas: R-134a).

❓ Is it possible to do without a vacuum pump?

Technically yes, but this will significantly reduce the service life of the system. Evacuation is necessary for:

• 🔹 Removing moisture (it freezes in the capillary tube and blocks the flow of freon).
• 🔹 Eliminating air (worsens heat transfer).

If there is no pump, you can try "blow out" the system with freon from a cylinder, but this is less effective.

❓ How to check if the new evaporator is working?

After filling with freon:

1. Turn on the refrigerator and wait 2 hours.
2. Check the temperature in freezer (should be −18°C and below).
3. Touch the tube at the outlet of the evaporator - it should be cold, but not freezing.
4. Listen to the compressor: it should work in cycles (turn on for 10-15 minutes, then turn off).

If the refrigerator works without stopping, but does not cool, the following are possible:

• 🔹 Lack of freon (needs to be refilled).
• 🔹 Capillary tube clogged (purge required).
• 🔹 Solder leakage (check with a soap solution).