Reports of some charterers making unusual requests on the ventilation of hygroscopic cargoes on passage highlight the need for all parties to be aware of the risks involved in taking readings of cargo hold atmospheres.
There are two rules that help the seafarer decide whether to ventilate a ship’s hold:
1. The 3-degree rule: Ventilate a hygroscopic cargo if the temperature of the outside air is at least 3°C below that of the cargo temperature (taken at loading).
2. The dew point rule: Ventilate when the dew point of the outside air is lower than the dew point of the air in the hold.
Please see attached file for details.
当心租家对吸湿性货物进行通风的要求
据悉，部分租家对在航程中为吸湿性货物进行通风的要求与常规做法不同，这提醒各方需要注意读取货舱空气指标所涉及的风险。
有两种方法可以帮助海员决定是否需要进行船舱通风：
1. 三度法：如果外部空气温度比货物温度（装货时的温度）低 3°C 或以上，应为吸湿性货物进行通风。
2. 露点法：当外界空气的露点低于舱内空气露点时，应进行通风。
详细信息请参阅附件。
