Which is Better, Air Cooler or Aluminum Pipe Row? How to Choose?

2025-02-28

The evaporator of a cold storage is an evaporator used in refrigeration equipment such as cold storages. Its principle is that the liquid refrigerant at low temperature and low pressure vaporizes and absorbs heat on one side of the heat transfer wall of the evaporator, so that the medium on the other side of the heat transfer wall is cooled. The cooled medium is usually water or air.

The evaporators of cold storages can be divided into two categories:
The first category: The evaporative pipe rows in the cold storage where air undergoes natural convection, such as the wall pipe rows and top pipe rows widely used in cold storages. Generally, they are in the forms of vertical pipes, single-row serpentine pipes, double-row serpentine pipes, double-row U-shaped pipes or four-row U-shaped pipes, etc.

Which is Better, Air Cooler or Aluminum Pipe Row? How to Choose?1740756747262

The second category: The air coolers where air is forced to flow. In order to improve the heat transfer performance, measures such as increasing the heat transfer temperature difference, adding fins to the heat transfer pipes or increasing the air flow rate are often taken to achieve the goal.

Advantages and Disadvantages of Air Coolers and Installation Schematic Diagram
Advantages:
The air cooler mainly relies on convective heat transfer. It is simple to construct, compact in structure, occupies a small space in the cold storage, and has little impact on the usable space of the cold storage. It has no requirements for the load-bearing capacity of the cold storage ceiling, and is relatively common in assembled cold storages and small Freon cold storages.

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It has high heat transfer efficiency, reduces the use of materials and lowers the cost. The air is forced to circulate by the fan, and the cooling speed of the cold storage is relatively fast. Defrosting is convenient and easy to control, and automatic control can be achieved, with convenient operation and easy management. Generally, in the market, it uses copper pipes with aluminum fins, which has a high pressure-bearing capacity, strong corrosion resistance, and is not easy to leak.
Disadvantages:
Due to the forced circulation of the fan, the air in the cold storage flows relatively fast, and the food in the cold storage is easily dried out, resulting in a large dry loss of the stored goods. Moreover, the fan itself consumes electrical energy, and the evaporator also needs to be defrosted frequently. Most small and medium-sized cold storages use electric heating wires to heat for defrosting. This periodic defrosting operation of the air cooler not only causes a waste of energy but also leads to an increase in the temperature inside the cold storage.
Precautions for Using Air Coolers:

The distance between the back of the air cooler in the cold storage and the thermal insulation board of the cold storage should be at least 300MM, which is conducive to the air circulation in the cold storage and convenient for future maintenance.
A U-shaped oil return bend should be set at the gas return port of the air cooler in the cold storage (depending on the refrigeration system) to facilitate the return of the refrigeration oil to the compressor of the cold storage.
A U-shaped bend should be set at the outlet pipe of the air cooler in the cold storage to form a liquid seal to prevent the air circulation between the inside and outside of the cold storage.

Installation Schematic Diagram of the Air Cooler in the Cold Storage:
Installation Schematic Diagram of the Air Cooler in the Cold Storage
Advantages and Disadvantages of Aluminum Pipe Rows and Installation Schematic Diagram
Advantages: The advantage of the aluminum pipe rows lies in that they have an advantage in the cold storage capacity compared with the fans. Without the need for a fan, they are more energy-efficient. Moreover, the dry loss of food is less, and the pipe rows have a high pressure resistance.
Disadvantages: They occupy a relatively large space, which affects the usable area to a certain extent. They mainly rely on radiant heat transfer, do not require a fan, and the cooling speed is slower than that of the fans. After frosting, the defrosting cycle is relatively long, generally twice a year. Defrosting methods can include frost sweeping, hot fluorine defrosting, etc. The defrosting water is not easy to handle. Generally, the aluminum pipe rows are not seamless pipes. Due to the microscopic thermal expansion and contraction, they are likely to leak after a long time. Their own heat transfer efficiency is relatively low, so the initial investment is relatively large. The aluminum pipe rows are suitable for use in freezers. Otherwise, condensed water will be generated, affecting the working environment.
Precautions for Aluminum Pipe Rows:
The aluminum pipe rows are hung on the ceiling of the cold storage with hooks or metal L-shaped pieces. A wooden keel cross lining with a thickness of 2.5-5 cm should be added. Especially for the aluminum pipe rows with specifications of 5.2m and 6.2m, there should be 6 hanging points, and a wooden keel cross lining with a thickness of 5 cm must be added on the top of the cold storage board to ensure the bearing strength of the aluminum pipe rows after frosting. At the same time, to avoid the cold bridge effect of the hooks, use foaming agents, etc. to seal the outer ends of the hooks passing through the cold storage board with thermal insulation materials to prevent cold loss through the hooks.
A gas return filter should be installed during the installation of the aluminum pipe rows to ensure the safe use of the compressor. When the compressor is higher than the position of the aluminum pipe rows, an anti-oil bend should be added. Add 1 for every vertical height of about 5m and 2 for about 10m. When installing the horizontal pipeline, a slope should be left.
Installation Schematic Diagram of the Aluminum Pipe Rows:

Reference for Choosing between Air Coolers and Aluminum Pipe Rows
For low-temperature cold storages or ultra-low-temperature cold storages, it is recommended to use pipe rows. In the market, many low-temperature cold storages use pipe rows. From a long-term perspective, the use of pipe rows makes the refrigeration capacity in the cold storage uniform, which is energy-saving and power-saving. However, it also has certain disadvantages. The price is relatively high, and the installation is not as convenient as that of the air cooler. Moreover, the initial construction cost will be much higher, which is also closely related to the budget of the cold storage owner.
It is completely possible to use an air cooler, and there is no need to worry about the problem of frosting. The air cooler has the characteristics of fast refrigeration and large cooling capacity. Air coolers are mostly used in medical cold storages, meat cold storages, etc. But when storing products such as fruits and vegetables, using an air cooler will cause serious water loss of the fruits and vegetables, making them shrivel and shrink.