The temperature for transporting frozen goods in refrigerated containers should not exceed -18℃. Typically, a 10-foot refrigerated container has an average cooling rate of 31.3℃/h when empty. However, after loading goods, the cooling rate significantly decreases due to the high heat capacity of the cargo, often taking 15-16 hours to reach the set temperature. If the initial incoming temperature is high, it may require 2-3 days to achieve the target temperature.
The temperature rise and fall rate in the refrigerated container is related to the goods loaded in the box. When the set temperature range of -18℃±3℃ is reached, the temperature in the box should be kept stable. However, when calculating the temperature rise in the refrigerated container when it is not refrigerated, the following empirical formula can be used as the standard value calculation
1) Cooled goods (without ventilation) 0.0054*(tw-tn)℃/h
2) Frozen goods 0.0067*(tw-tn)℃/h
Where tw and tn are the outside temperature and the temperature in the box ℃ respectively.
