Never ignore the step-by-step cooling of an empty cold storage warehouse; these precautions are extremely important!

                                                                                                      Why is it necessary to cool down an empty warehouse?

The process of cooling the empty cold storage needs to be carried out gradually to ensure that the building structure of the cold storage is not affected by excessive temperature differences. This is because the temperature difference between the inside and outside of the cold storage will cause certain thermal expansion and contraction effects on the enclosure structure (such as walls, floors, roofs, etc.). If the temperature drops or rises too quickly, it may cause damage to the building structure.

Fland reminds you: Cooling the empty cold storage is an important measure to ensure a stable storage environment, extend the shelf life of items, improve storage quality and reduce operating costs.

                                                                                           What are the requirements for cooling an empty warehouse?

For civil construction cold storage and cold storage with cement floors poured inside (i.e., five-sided cold storage), it is necessary to gradually cool down in stages to keep the temperature stress and dry shrinkage rate of the main structure and each part of the building structure balanced, which can prevent cracks and the formation of frost and ice on the ground and walls.

1.The cooling process should be carried out gradually

Slow cooling down：Before using a cold storage, it must be run empty. To prevent the enclosure structure from being damaged due to excessive temperature differences, the temperature of the cold storage should be reduced slowly and gradually. Generally, the cooling rate is required not to exceed 1-2°C/h, especially during the initial cooling period, when the temperature change should be more stable.

According to the materials of the enclosure structure:It should be noted that different building materials (such as concrete, steel structures, insulation materials, etc.) have different thermal expansion and contraction characteristics. Therefore, the cooling rate should be controlled according to the specific materials of the cold storage's enclosure structure. The specific cooling methods are as follows:

2. The temperature gradually drops to the target range

Initial cooling stage: The initial cooling stage of a cold storage is usually rather slow, especially having a significant impact on building parts such as walls, floors, and roofs. When the cooling begins, the temperature inside the warehouse should gradually drop to around 10°C to 5°C to avoid rapid temperature changes. 

Stabilization stage: After the initial cooling, the temperature should be further and gradually reduced until it reaches the target storage temperature of the cold storage (for example: -18°C or lower), but it is necessary to ensure the uniformity and stability of the cooling process.

3. Moisture precipitation from the enclosure structure

Gradual precipitation of moisture: The enclosure structure of newly-built cold storage may contain a certain amount of moisture. The cooling process should be slow enough to allow the moisture in the building materials to gradually precipitate, avoiding rapid cooling which may cause moisture condensation and form condensate water. 

Wall drying: Especially for five-sided concrete structure cold storage, the release of moisture during the cooling process is very important. The cement floor must be thoroughly dry to ensure that the moisture within the wall, ceiling and floor materials does not condense rapidly, preventing water vapor penetration or water droplets from causing damage to the goods.

4. Maintenance and care after cooling

When the set temperature is reached, the machine should be stopped, the warehouse sealed for heat preservation for more than 24 hours, and the temperature rise in the warehouse and the heat preservation effect should be observed and recorded.

5. Cooling measures for different cold storage facilities

High-temperature storage rooms and controlled atmosphere storage rooms can be directly reduced to the designed temperature and should be maintained for 24 hours. Only when there are no abnormal changes at the junction of the floor and the warehouse panel, the floor surface and other places can the warehouse temperature be reduced to the designed temperature. In addition, for small combined cold storage with a non-concrete floor surface, when the cold storage is empty and cooled, the temperature inside the cold storage can be directly reduced to the designed temperature.

In conclusion, the core requirements for cooling an empty warehouse are to control the cooling rate, maintain a uniform temperature distribution, ensure the adaptability of the building structure, and avoid damage to equipment or buildings due to excessive cooling, thereby extending the service life.