Creating your own refrigerated warehouse is a complex, but completely solvable task for an entrepreneur seeking to optimize the costs of storing perishable products. Independent installation allows you to save significant money on contractor services, but requires a deep understanding of thermodynamics and building codes. Before purchasing materials, it is necessary to clearly determine the purpose of the future chamber: will it be medium temperature a warehouse for vegetables or low temperature a freezer for meat and fish.
The key element of the entire system is the correct calculation of heat inflows, on which the choice of compressor-condensing unit directly depends. Errors at the design stage can result in equipment that is overloaded, consumes excess power, and frequently fails. In this article we will look at how to make a refrigerated warehouse that will be reliable and energy efficient.
The construction process is divided into several critical stages: preparing the base, assembling the thermal insulation circuit, installing doors and installing the refrigeration machine. The tightness of the joints of the panels is the only guarantee that the set temperature will be maintained inside without the formation of condensation. Violation of the assembly technology even in one place can negate all efforts and financial investments.
Selecting a location and preparing the room
The first step in solving the problem of how to make a refrigerated warehouse is choosing a suitable room. This could be a separate building, an extension or a dedicated area within an existing warehouse. The main requirement for the premises is the presence of a flat, durable floor that can support the weight of the products and equipment. If you plan to store goods on pallets, the load per square meter can reach several hundred kilograms.
It is important to consider the height of the ceilings, as it limits the possible height of the chamber itself. It is also necessary to provide electricity supplies of appropriate power. Industrial refrigerators often require three-phase voltage 380 V, especially if the compressor power exceeds 3-4 kW. The lack of sufficient power will lead to constant knocking out of machines and damage to products.
The room should be dry and protected from direct sunlight, which heats the outer walls of the chamber and increases the load on the refrigeration unit. Ventilation in the room itself also plays a role: the air around the condenser must circulate freely for effective heat removal. If the room is too small, you will need to organize forced air supply and exhaust.
⚠️ Attention: Do not install the camera in places where direct contact with water or high humidity is possible without additional waterproofing, as this will accelerate the corrosion of metal structural elements.
Before starting work, it is necessary to carry out thorough cleaning and, if necessary, if necessary, level the floor. To do this, self-leveling mixtures or laying an additional layer of concrete are often used. A flat surface is critical for the correct joining of floor panels, which are the foundation of the entire structure.
Calculation of dimensions and selection of thermal insulation panels
The basis of any refrigerated warehouse is sandwich panels. They consist of two sheets of metal (usually galvanized steel or stainless steel) and a layer of insulation between them. The most common and effective material for thermal insulation is polyisocyanurate foam (PIR) or polyurethane foam (PUR). These materials have a minimal coefficient of thermal conductivity and do not absorb moisture.
The thickness of the panels is selected depending on the temperature regime that is planned to be maintained inside. For medium temperature chambers (0 to +10 °C) a thickness of 100 mm is usually sufficient. If you are building a freezer (below -18 °C), then the insulation thickness should be at least 150 mm, and in some cases 200 mm. Using thinner panels for the freezer will lead to freezing of the structure and the formation of ice.
When calculating the size of the warehouse, take into account not only the internal volume, but also the dimensions of the panels, which often have a standard width of 1180 mm. This will help minimize the amount of trim and waste when cutting. It is also important to determine in advance the type of locking connection of the panels: the most reliable are considered to be locks of type Excentric or Z-Lock, providing high tightness.
The table below shows the recommended panel parameters for different types of storage:
| Chamber type | Temperature conditions | Panel thickness | Insulation density |
|---|---|---|---|
| Vegetable storage | +2...+10 °C | 100 mm | 35-40 kg/m³ |
| Meat warehouse | 0...+4 °C | 100-120 mm | 40 kg/m³ |
| Frozen (Freezer) | -18...-25 °C | 150-200 mm | 40-45 kg/m³ |
| Shock freezing | -35...-45 °C | 200 mm | 45 kg/m³ |
When choosing panels, pay attention to the thickness of the metal coating. For warehouses with high traffic and the use of forklifts, it is better to take steel with a thickness of at least 0.7 mm to avoid dents from accidental impacts. Thinner metal (0.5 mm) is suitable for static storage of boxes.
Mounting the base and assembling the chamber frame
Assembling the refrigerator begins with laying the floor panels. If the chamber is small, you can use ready-made sandwich panels. For large warehouses, a “pie” is most often made: waterproofing, insulation (expanded polystyrene), reinforced concrete screed with topping. Metal sheets or special panels are laid on top of the screed. It is important to provide a thermal joint between the foundation of the building and the warehouse slab to avoid cold bridges.
After preparing the foundation, installation of wall panels begins. Installation starts from the corner. The panels are connected to each other using locking joints, which are coated with a special sealant for reliability. The sealant must be frost-resistant and remain elastic at low temperatures. Each panel is fixed to the floor using corners or guides.
☑️ Preparation for assembly
The vertical installation of the panels is controlled by a level. Distortions are unacceptable, as they will lead to a loose fit of the ceiling panels and a violation of the tightness. The joints of the panels from the outside and inside are additionally foamed with polyurethane foam with a low coefficient of expansion so as not to deform the metal.
After assembling the walls, they proceed to installing the ceiling panels. This is the most difficult stage, requiring the use of lifting mechanisms or scaffolding. Ceiling panels are also sealed and fixed. Particular attention is paid to the passage of communications and fasteners - all holes must be carefully sealed.
⚠️ Attention: When drilling panels, use drills with a depth limiter so as not to damage the inner layer of insulation and not to compromise the integrity of the inner lining of the chamber.
The final stage of assembly housing is the installation of corner profiles (platbands) inside and outside the chamber. They cover the joints of the panels, protect the locks from mechanical damage and give the structure an aesthetic appearance. It is recommended to make all internal corners rounded (fillets) to facilitate sanitary treatment and prevent the accumulation of dirt.
Installation of a refrigeration door and vestibule
The door is the most vulnerable element of the thermal insulation circuit. For refrigerated warehouses, special doors with electrically heated perimeter are used, which prevents the sheet from freezing to the frame and the formation of condensation. Doors can be hinged or sliding. For warehouses with heavy movement of goods, sliding doors are preferable, since they do not take up useful space inside the chamber.
When installing the door frame, it is necessary to ensure a perfect tight fit. To do this, a magnetic seal is installed around the perimeter of the door. If the door will open frequently, it makes sense to install a vestibule (gateway). The vestibule is a small intermediate space with two doors that never open at the same time. This allows you to maintain the temperature in the main chamber and save energy.
Why does the door frame heat up?
The refrigerator door frame heats up not because of a breakdown, but thanks to the built-in heating element. This is necessary to equalize the temperature of the frame surface with the ambient temperature, preventing the formation of condensation (“dew”) and subsequent freezing of the door. It is impossible to turn off the heating.
Inside the warehouse, emergency lighting and an emergency button for opening the door from the inside must be installed. This is a safety requirement: a person who accidentally finds himself locked in a closed chamber must be able to get out even if the lock is locked. The button should be bright, noticeable and not require a key to activate.
For large warehouses, additional curtains made of PVC strips are often installed in the doorway. They allow the passage of personnel and even the passage of forklifts, minimizing the loss of cold. The strips must be elastic at low temperatures and have antibacterial properties.
Installation of refrigeration equipment and ventilation
The heart of the warehouse is a refrigeration unit, consisting of a compressor-condensing unit (CCU) and an air cooler (evaporator). The KKB is usually installed outside the building or in a separate technical room so that noise and heat do not interfere with the operation of the warehouse. The evaporator is mounted inside the chamber on the ceiling or walls using brackets.
The blocks are connected by copper pipelines that pass through the chamber wall in special sleeves. Pipe passages must be hermetically foamed and insulated. Pipelines must be covered with thermal insulation (rubber or foamed polyethylene) to prevent loss of cold and the formation of condensation on the surface of the pipes.
An important aspect is the organization of condensate drainage. When the air cooler operates, moisture forms on its fins, which must be drained into the drainage system. The drain hose is laid with a slope, and a water seal (water seal) is installed at the exit from the chamber to prevent cold air from escaping through the drain.
After installing the pipelines, the system is evacuated with a special pump to remove moisture and air, and then charged with refrigerant (freon). The type and amount of refrigerant are indicated on the equipment nameplate. Refueling must be carried out by a qualified specialist using scales and a pressure manifold.
Electrics, automation and system setup
Electrical installation work is the final and most critical stage. All cables must be laid in corrugated pipes or cable ducts. Wiring with heat-resistant insulation is used inside the camera. A residual current device (RCD) and circuit breakers corresponding to the current load of the compressor and heating elements must be installed.
Temperature control is carried out by a controller that reads sensor readings and turns the compressor on/off. Temperature sensors should be installed in an area where air circulates, away from direct flows from the evaporator and doors. For large-volume warehouses, it is recommended to use several sensors to monitor the temperature at different points.
It is also necessary to set up the evaporator defrost system. During operation, a “coat” of ice grows on the evaporator fins, which impairs heat transfer. The controller periodically turns on the defrost heating elements to melt the ice. The defrost mode (start time, duration, end temperature) is selected individually depending on the humidity of the products and the frequency of door opening.
After turning on the system, it is necessary to conduct a test run within 24 hours. At this time, the tightness of the connections, the absence of extraneous noise, vibrations and the correct operation of the automation are checked. Only after successful completion of the test, the warehouse-refrigerator is ready to be loaded with products.
How often do you need to change the oil in the compressor?
In modern hermetic and semi-hermetic compressors used in warehouse refrigerators, the oil is filled for the entire service life and does not require regular replacement during normal operation. Replacement may only be required after major repairs, winding burnout, or moisture entering the system. In open compressors, the oil level is checked through a sight glass, and if necessary, it is topped up or changed according to the manufacturer's regulations.
Why does ice form on the floor in the chamber?
Icing on the floor most often indicates a broken door seal or improper operation of the defrost system. If the door doesn't close properly, warm, moist air gets in and moisture condenses on the cold floor. Also, the cause may be clogged drainage, when the water from the defrost does not have time to leave and freezes under the evaporator, spreading throughout the chamber.
Is it possible to use a regular air conditioner to cool a warehouse?
It is absolutely not possible. Air conditioners are designed for comfortable cooling of people (up to +18...+20 °C) and are not capable of operating at subzero temperatures. When attempting to cool a warehouse to 0°C or below, the air conditioning compressor will fail due to the lack of an oil cooling system and operation outside the permissible pressure range. Specialized refrigerating machines are used for warehouses.
What is the service life of a refrigerated warehouse?
The service life of a properly installed refrigerated warehouse is 15-20 years or more. PIR/PUR sandwich panels practically do not lose their properties over time. The main wear and tear is on refrigeration equipment (compressors, fans), which with regular maintenance lasts 7-10 years before major repairs or replacement.
Is it necessary to register a refrigerated warehouse?
A refrigerated warehouse itself as a structure does not require registration, unless it is a permanent structure (often these are non-capital prefabricated designs). However, refrigeration equipment containing freon is subject to registration with the relevant environmental services (depending on the country and the volume of refrigerant), and also requires regular maintenance by licensed specialists.