In logistics and commercial transportation, there is often a need to transport goods that require special temperature conditions. When we see a truck on the road with steam coming out of it or the hum of a working unit being heard, many people have a question: what is the name of a car with a refrigerator? The correct answer is refrigerator. This is a specialized vehicle equipped with a heat-insulated body and a refrigeration unit that allows you to maintain a given temperature inside, regardless of external conditions.
Such equipment is indispensable for the delivery of perishable foods, medicines, flowers and even some types of industrial goods. Such a vehicle differs from an ordinary Gazelle or truck not only in the presence of cooling equipment, but also in the design of the body, which must retain cold. Thermal van without an active installation it can only maintain the temperature for a short time, while a full-fledged refrigerator is capable of cooling the cargo or keeping it deep frozen throughout the entire journey.
Understanding the differences between types of bodies and the principles of operation of refrigeration equipment is critically important for customers and logisticians. An error in choosing the type of transport can lead to damage to expensive cargo. In this article we will analyze in detail how these machines are designed, how they differ from each other and what are the nuances of their operation in modern conditions.
Main types of transport for transporting cold
Not all vehicles transporting cold goods are full-fledged refrigerators. There is a gradation depending on the presence of an active refrigeration unit and the quality of thermal insulation. The first level can be considered isothermal van. This is a vehicle whose body is made of sandwich panels with low thermal conductivity. It does not have its own source of cold; it only slows down the heating of the load due to inertia. Such vehicles are suitable for short transportation, for example, delivery of ice cream from a warehouse to a store within the same city.
The second, more complex type is precisely refrigerator. The key difference is the presence of an autonomous or dependent refrigeration unit (RU), which actively cools the space inside the body. This allows products to be transported over thousands of kilometers, maintaining temperatures from +20°C to -25°C and below. There are also combined options, where the body is divided into sections with different temperature conditions, which allows you to simultaneously transport, for example, frozen meat and chilled fish.
- ❄️ Isotherm - a body without a refrigerator, keeps the temperature due to insulation.
- 🚛 Refrigerator - a car with active refrigeration unit and powerful insulation.
- 🌡️ Thermal container - a removable container with phase-transition material or dry ice.
The choice between an isotherm and a refrigerator depends on the duration of the route and the type cargo If the travel time takes several hours and the cargo is already cooled, an insulated body is sufficient. However, for interregional and international transportation, where travel time is calculated in days, the use of autonomous refrigeration unit is a mandatory requirement of sanitary standards.
⚠️ Attention: When ordering transport, always check the body type. The phrase “car with a refrigerator” in everyday life can mean either a refrigerator or simply an insulated van, which can be a fatal mistake for long-term transportation of perishable goods.
Design of a refrigeration unit on a car
The heart of any refrigerator is the refrigeration unit. It works on a compression cycle principle similar to household refrigerators, but on a much larger scale. The main elements of the system are a compressor, a condenser, a receiver-dryer, a thermostatic valve and an evaporator. The compressor compresses the refrigerant, increasing its pressure and temperature, after which the gas enters the condenser, where it is cooled and turned into liquid.
The most important element of the system is evaporatorwhich is located inside the cargo compartment. It is through it that air is driven, cooled and distributed throughout the body. For effective operation, it is necessary that air flows circulate freely, not blocked by cargo. Therefore, in refrigerators, aluminum floors with T-shaped profiles are often used, creating a gap between the floor and the load for the passage of cold air.
Cycle diagram: Compressor → Condenser → Receiver → Expansion valve → Evaporator → CompressorBy the type of compressor drive, installations are divided into several categories. Dependent systems operate from the vehicle engine through a belt drive or directly from the gearbox. They are cheaper, but cannot work when parked with the engine off. Autonomous units have their own diesel or gasoline engine, which allows them to operate independently of the car. There are also electrical installations connected to a 220V or 380V network, which are often used in urban areas or at loading terminals.
Thermal insulation of the body and materials
The operating efficiency of the refrigeration machine directly depends on the quality of the body’s thermal insulation. The main materials for the production of modern refrigerators are sandwich panels. They are a multi-layer structure, with a layer of insulation between two sheets of durable plastic (often fiberglass reinforced) or metal. The most common insulation material is polyurethane foam (PPU), which has an extremely low thermal conductivity coefficient.
The thickness of the walls, floor and ceiling of such a body can vary from 40 to 100 mm or more, depending on the class of the refrigerator. To transport deep-frozen cargo (down to -25°C), reinforced panels of maximum thickness are required. An important aspect is tightness. Any gap in the doors or panel joints will lead to the influx of warm air and condensation, which can spoil the cargo and load the refrigeration unit.
| Body type | Skin material | Insulation | Thickness walls (mm) |
|---|---|---|---|
| Light isotherm | Galvanized steel | Foam plastic | 30-40 |
| Standard ref | Plastic/Aluminium | PPU | 50-60 |
| Freezer | Reinforced plastic | High density PPU | 80-100+ |
Particular attention should be paid to the condition of the door seals. Over time, rubber hardens and cracks, losing its properties. Regular inspection and replacing rubber seals is a simple but effective measure for maintaining cold. It is also worth remembering that the inner surface of the body must be smooth and easy to clean in order to meet sanitary requirements when transporting food products.
Classification of refrigerators by temperature conditions
In international practice and in accordance with ATP standards (Agreement on the Transport of Perishable Products) Refrigerators are divided into classes depending on the range of temperatures they maintain. This division helps logisticians select transport for a specific type of cargo. For example, to transport bananas you need one mode, and for ice cream - a completely different one.
Class A is intended for transporting goods at temperatures from +12°C to 0°C. This is ideal for chilled meat, fish, dairy products and vegetables. Class F (or sometimes classified as Class C) allows temperatures down to -20°C or lower, which is necessary for frozen foods. There are also multi-temperature machines, where the body is divided by partitions that allow the creation of different zones.
- 🥦 Class A — from +12°C to 0°C (refrigerated products).
- 🍗 Class B — from +12°C to -10°C (mixed cargo).
- 🍦 Class C/F — from +12°C to -20°C and below (freezing).
☑️ Checking the readiness of the refrigerator for the trip
It is important to understand that the refrigeration unit is not intended for freezing a warm product. Its task is maintain the already achieved state of the cargo. If you load warm goods into a refrigerator, the unit will work hard, trying to cool the entire volume, which can lead to compressor failure and damage to cargo on adjacent pallets.
⚠️ Attention: Sanitary rules may change. Before preparing documents for the transportation of specific cargo (for example, vaccines or poultry meat), check the current requirements of Rospotrebnadzor or international standards, since acceptable temperature ranges may be revised.
Operation and maintenance of refrigeration equipment
Working with a refrigerator requires compliance with certain operating rules. Before each loading, the body must be ventilated and, if necessary, disinfected. The refrigeration unit should be started in advance so that it has time to cool not only the air, but also the walls of the body, displacing the accumulated heat. This process is called pre-cooling.
Regular maintenance includes checking belt tension (if engine driven), compressor oil level and condition of condenser radiators. Dirt and fluff clogging the radiator honeycombs significantly reduce the efficiency of heat transfer, causing the unit to operate longer and consume more fuel. Radiator cleaning should be carried out regularly, especially in the summer.
What will happen if you ignore maintenance of the control unit?
Ignoring maintenance will lead to increased pressure in the system, overheating of the compressor and eventual failure of expensive components. Repairs can take weeks, and a downtime of a car can cost a lot of money.
The driver or forwarder must constantly monitor the thermostat readings. Modern systems are equipped with “black boxes” that record all temperature fluctuations. In the event of cargo defrosting, this data will become evidence of violation of transportation conditions. Therefore, it is important not only to monitor the equipment, but also to place the cargo correctly without blocking the air flow.
Problems and typical malfunctions
Like any complex equipment, refrigerators are susceptible to breakdowns. One of the most common problems is refrigerant (freon) leakage. This may occur due to vibration, tube corrosion or mechanical damage. Symptoms include decreased cooling efficiency and the appearance of oily spots under the unit. Self-refueling without searching for a leak makes no sense and is harmful to the environment.
Another common problem is evaporator freezing. This happens if there is high humidity in the body or the seal is broken. Ice blocks air circulation and temperatures begin to rise. In such cases, a cycle is required, which in modern installations occurs automatically, but sometimes requires manual intervention. Temperature sensors also often fail, starting to “lie” and giving false commands to the controller. defrost, which in modern installations occurs automatically, but sometimes requires manual intervention. Temperature sensors also often fail, starting to “lie” and giving false commands to the controller.
It is worth mentioning problems with the installation’s motor (for autonomous versions). Overheating, problems with the fuel system or starter can leave the load cold in the middle of the highway. Therefore, having a serviceable a stock of spare parts and knowledge of the basic operating principles of a diesel engine for a refrigerator driver is a mandatory requirement.
How often do you need to undergo maintenance of a refrigeration unit?
The recommended maintenance frequency is every 500-1000 operating hours or every six months, depending on the intensity of operation. However, a visual inspection of radiators and checking the tension of belts should be carried out before each long-distance flight.
Is it possible to transport non-food cargo in a refrigerator?
Yes, it is possible if the cargo is not toxic and will not damage the interior trim of the body. However, after transporting chemicals or construction materials, thorough washing and disinfection will be required before transporting the products again. The sanitary certificate of the body must be in order.
Why can’t you turn off the unit in a refrigerator at night?
Switching off the unit leads to rapid heating of the cargo, especially if the tightness of the body is broken or the thermal insulation is not ideal. For frozen foods, even a short-term increase in temperature above the critical point triggers irreversible processes of destruction of the structure of the product.