In the professional refrigeration industry, the term “medium temperature” is heard often, but not all entrepreneurs understand its exact meaning and technical nuances. Medium-temperature refrigerator is specialized equipment designed for storing products at temperatures from -5 to +10 degrees Celsius. It is this range that is considered optimal for maintaining the freshness of most food products that do not require deep freezing, but quickly spoil at room temperature.
Understanding the difference between different types of refrigeration equipment is critically important when equipping a store, warehouse or restaurant. If you choose a chamber with an unsuitable temperature regime, this will either lead to damage to the goods, or to excessive energy consumption and premature wear of the compressor. In this article, we will analyze in detail how such systems are designed, how they differ from freezers, and what to look for when choosing.
The main task of such equipment is to maintain a stable microclimate. Unlike household analogues, industrial models must cope with frequent opening of doors and large loading volumes. Evaporator and compressor they are selected so as to quickly restore the set temperature after a leak. This is a complex engineering system that requires proper configuration.
Design features and system design
The fundamental difference between medium-temperature refrigerators and household or low-temperature analogues lies in the design heat exchangers and the power of the compressor group. Evaporator in such chambers it often has a large surface area for effective heat removal with a small temperature difference between the refrigerant and the air in the chamber. This allows you to avoid overdrying of food, which often happens in freezers.
The most important element is the defrosting system. Since the temperature in the chamber is positive or close to zero, moisture from the air actively condenses on the evaporator. To remove this moisture, shadow defrost (natural, when the compressor stops) or electric defrosting is used. The choice of method depends on the humidity conditions of the room and the frequency of opening the doors.
- 🧊 Compressor-condensing unit (CCU): the heart of the system, which circulates the refrigerant and compresses freon vapors.
- ❄️ Air cooler: a device inside the chamber where heat exchange and air cooling occurs.
- ⚙️ Thermostatic valve (TRV):a mechanism that meteres the supply of liquid refrigerant to the evaporator depending on the load.
The body of such refrigerators is usually made of sandwich panels 80 or 100 mm thick. For medium-temperature conditions, 80 mm is most often sufficient, since the temperature difference between the street and the chamber is not extreme. However, for northern regions or unheated warehouses, it is recommended to use 100 mm thick panels to minimize heat gain.
⚠️ Attention: When assembling the chamber, pay special attention to the tightness of the panel joints. Even a microscopic gap in corner joints will lead to the formation of “cold bridges” and ice freezing in the corners, which can deform the structure over time.
Temperature conditions and their effect on products
The main parameter that determines the classification of equipment is the operating range temperatures. Medium-temperature refrigerators (often marked MM or MX depending on the type) operate in the range from -5°C to +10°C. This is the “golden mean” for storing most gastronomic goods.
In this range, biological processes in products slow down, but do not stop completely, as with deep freezing. This allows you to preserve the texture, taste and vitamin composition of fresh vegetables, fruits, meat and dairy products. Violation of this regime even by a couple of degrees upward can trigger the active proliferation of bacteria.
There is a clear division into types of products that require different conditions:
- 🥦 Vegetables and fruits: require high humidity (up to 90-95%) and temperature +2...+6°C.
- 🥩 Meat and fish (chilled): stored at 0...+4°C, require good air circulation.
- 🧀 Cheeses and milk: sensitive to drafts, optimally +4...+8°C.
For precise control of parameters it is necessary to use calibrated sensors. Built-in thermostats may have errors, so professionals recommend installing thermographs or digital temperature recorders. This will allow you to keep a history of temperature conditions and prove compliance with sanitary standards during inspections.
Types of medium-temperature equipment
The market offers many options for the design of refrigeration chambers. The choice depends on the area of the premises, the type of product and the logistics of the warehouse. The main division occurs according to the method of installation and configuration.
Prefabricated chambers is the most popular option. They are assembled from panels on site. Their advantage is that the camera can be disassembled, transported to another place and reassembled, while changing the dimensions (add or remove sections). This is an ideal solution for rented premises.
Monoblocks are a ready-made unit where the compressor, condenser and evaporator are combined in one housing. They are mounted into the chamber wall or installed on top. This is an all-in-one solution that only requires connecting to the mains and making a hole in the panel.
| Type of equipment | Installation | Dimensions | Application |
|---|---|---|---|
| Collection chamber | Complex, on site | Any | Warehouses, supermarkets |
| Monoblock | Simple, insert | Standard | Convenience stores, cafes |
| Split system | Labor-intensive (highways) | Any | Food production |
It is worth mentioning separately split systems. In them, the compressor-condensing unit is placed outside the chamber (outside or into a technical room), and only the evaporator is located inside. This allows you to reduce noise and heat gain indoors where people are.
What is the difference between a monoblock and a split system?
In a monoblock, all components are located in one housing, which either hangs on the wall or is placed on the roof of the chamber. In a split system, the unit is divided into two parts connected by copper pipelines. Split systems are quieter and allow you to place a noisy compressor far from the shopping area.
Areas of application in business and industry
The scope of use of medium-temperature refrigerators is incredibly wide. Almost any business related to the circulation of food products cannot do without this equipment. From a small one at home to giant logistics centers.
In retail trade such chambers are used to create inventories of goods. While the display cases are filled with goods for customers, the main stock is stored in the storage room. Here it is important to ensure convenient access and correct sorting in order to minimize the time it takes to open the door.
In restaurant business (HoReCa) the requirements are even stricter. Semi-finished products, ready-made dishes and ingredients are stored here. Chambers with separate sections or modular designs are often used. An important aspect is to respect the proximity of the product - you cannot store fish next to ready-made baked goods.
Mid-temperature chambers are used to ripen products (for example, cheeses or deli meats) or to store raw materials before processing. Here, precise adjustment of humidity and ventilation is often required, which can be solved by installing additional equipment. Food production Medium temperature chambers are used to ripen products (such as cheeses or deli meats) or to store raw materials before processing. Here, precise adjustment of humidity and ventilation is often required, which can be solved by installing additional equipment.
Energy efficiency and resource saving
Refrigeration equipment is one of the main consumers of electricity in a sales area or warehouse. Therefore, the issue of energy efficiency is acute. Modern compressors with frequency regulation (inverter) can significantly reduce costs.
The principle of operation of the inverter is simple: instead of constantly turning on and off at full power, the compressor smoothly adjusts its performance depending on the current thermal load. This not only saves electricity, but also extends the life of the engine by eliminating starting currents.
The quality of the thermal insulation of the panels also plays an important role. The use of panels with type locks EXCENTRIC or ZIP provides better tightness compared to conventional locks. In addition, installing doors with electric heating and automatic closing prevents the loss of cold.
- 💡 LED lighting: replace old lamps with LED ones, they heat the air inside the chamber less.
- 🚪 PVC curtains: installing curtains on the doorway reduces the loss of cold when people pass by.
- 🧹 Cleanliness of the condenser: regular cleaning of the heat exchanger from dust improves heat transfer.
⚠️ Attention: Do not install the refrigeration chamber near heat sources (batteries, direct sunlight, hot workshops). Elevated ambient temperatures force the compressor to work at its limit, which leads to accidents.
Maintenance and typical malfunctions
Even the most reliable equipment requires regular attention. Scheduled maintenance (MRO) allows you to identify problems at an early stage. Typically, maintenance is carried out once a quarter or once every six months, depending on the intensity of operation.
One of the common problems is refrigerant leak. If you notice that the chamber has stopped gaining temperature or the compressor is running non-stop, this is the first sign. Also, oil or frost may appear on the evaporator tubes in unusual places.
Another common problem is contactor failure Defrosting heating elements or sticking. As a result, a “coat” of ice builds up on the evaporator, which blocks the air flow. The fan is humming, but there is no cold. It can be solved by replacing the heating elements and checking the drainage system.
☑️ Monthly check of the refrigerator
It is important to monitor the condition of the drainage. If the drain hole becomes clogged with dirt or freezes, water will flow over the edge of the pan and flood the floor or food. To prevent this, a heating cable is often installed in the drainage tube heating cable.
Criteria for selecting equipment for business
Choosing a medium-temperature refrigerator is an investment that should pay off. You cannot buy equipment by eye. It is necessary to calculate heat inflows, taking into account the volume of the room, the number of times the doors are opened and the ambient temperature.
Pay attention to the brand of the compressor. Market leaders (such as Bitzer, Copeland, Danfoss) guarantee reliability and availability of spare parts in the future. Cheap analogues may fail in a year, and it will be impossible to find a repair kit for them.
The type of refrigerant is also important. Modern environmental standards dictate the use of freons with low global warming potential (GWP), such as R134a or R449A. The use of obsolete refrigerants (R22) is gradually being limited by legislation in many countries.
Prospects for the development of refrigeration technologies
The industry does not stand still. The future belongs to “smart” control systems that allow you to control the temperature and condition of equipment via a smartphone. IoT technologies (Internet of things) are being implemented even in budget models.
Business owners have the opportunity to remotely monitor temperature graphs and receive notifications about accidents in real time. This reduces the risk of product damage and allows technical service operators to react proactively before the product is damaged.
How often should a medium-temperature refrigerator be defrosted?
Modern chambers with automatic defrosting do not require manual defrosting. However, if the defrost system is faulty or the door does not close tightly, defrosting may be necessary. On average, it is recommended to carry out scheduled defrosting and washing 1-2 times a year.
Is it possible to store meat and vegetables in the same chamber?
Theoretically, the temperature regime for them is similar (+2...+6°C). However, storing them together is not recommended due to the risk of cross-contamination and odor transfer. The meat should be hermetically packaged, and ideally, placed in a separate section or chamber.
What is the service life of an industrial refrigerator?
With regular maintenance and high-quality components, the service life of the chamber can be 10-15 years or more. Compressors usually last about 7-10 years before major repairs or replacement.
Why does ice form on the ceiling in the chamber?
This is a sure sign of a leak (the door is poorly closed, the seal is torn) or a malfunction of the defrost system. Warm, moist air gets inside, condenses on cold surfaces and freezes.