The refrigerator should first be used to maintain the temperature, that is, to maintain the temperature of the original items, such as the blankets we use to sell cold drinks, and then wrap the goods. When the external cooling source enters the human body through radiation, conduction, and convection, the refrigeration equipment is blown out of the cold air and removed, and the insulation source enters the goods.
Refrigerated trucks are included in refrigeration equipment and extended to refrigerated mobile vehicles. Below, the refrigeration unit editor will explain the precautions for using refrigerated trucks:

Before loading, it is necessary to pre cool or preheat for about 1.5 hours. Due to the vehicle being parked in the open air, the temperature of the sedan is usually in the external environment. The ambient temperature of the sedan can affect the transportation temperature of the goods, resulting in changes in the transportation quality of the goods. Therefore, the sedan needs to be pre cooled to the required temperature before loading.
It is necessary to turn off the refrigeration equipment when loading and unloading goods. Many people do not turn off the refrigeration unit when loading and unloading goods, which is a very wrong operation.
The principle is that when the car is pre cooled, if it is not turned off, the fan of the refrigeration evaporator is working when the car is turned on. The front of the fan is positive pressure, and the back is negative pressure. Therefore, the cold air from above and below will quickly suck in hot air, causing the temperature inside the car to rise rapidly.
If the car is turned off and the goods are reloaded, the air activity in the car meter will stop, and the air pressure will be consistent, so the transmission of external air to the car is relatively slow.
When using a refrigerated truck, the floor of the compartment should be kept clean. Due to the action of the evaporator fan, air circulates inside the car, causing debris or soil on the ground to be sucked in by the evaporator fan. The long-term effect will cause a large amount of magazines to enter the evaporator coil, which will affect the cooling effect of the refrigeration unit.
Proper packaging is crucial for protecting goods. If freezing goods, different air packaging should be used. Due to the wind blowing over the surface of frozen goods, water loss can occur, resulting in a decrease in the quality of the goods.
Do not stack the goods too high during loading, ensuring that the height of the goods is not higher than the level of the export. When loading, it is necessary to use double-sided pallets to ensure the circulation of cold air on the ground.