Within refrigerated warehouses, condensation may arise and that water will be frozen, and the cooling functions will be reduced, and for products being delivered inside temperature controlled trucks due to the drop to normal environment temperature, the surface of the outside packages may get wet.
This is also the cause for rust on the metal cans, strength decrease or mold on carton boxes.
Actually, if you understand well the condensation mechanism, it is important to minimize this condition.
The atmosphere to preserve low temperature environment comprises 21% humidity.
This air that contains water vapor is called misty air.
However, due to the limitation in the water volume that can be stored in the air, if over this limitation, the vapor water will become supersaturated and then condensed.
If the temperature is high, the storable water volume is also high, and low if the temperature is low.
Actually, if it is easy to refrigerate misty air, at some temperature point, the volume of water being stored in the air will be condensed due to the increase in the storable water volume.
Moreover, if the air of the ante-room touches the air inside the warehouse, it will immediately be condensed, and repeatedly be frosted.
Though it is impossible to completely prevent condensation, the important thing is to control it to an extent that this does not become a problem.
In order to utmost manage this, the airtightness of the dock shutter of the ante-room is important, and closing the entrance of the warehouse tightly is fundamental.
For this purpose, auto-door is mostly used, but it is also necessary to take preventive measures such as using precision machines like forklifts.
Regarding facilities, installing dehumidifier in the ante-room as well as curtains or noren are also effective.
In the cold chain system, besides raw products such as vegetables, fruits, fish and shells, non-food flowers are also of this category.
In the food material supply chain for restaurants and home-cooked food outlets, it is necessary to categorize this together with processed food type.
For raw products, because of physically active elements such as heat, humidity, ethylene gas and hot weather, gas could be created.
Because vegetables are manufactured in expensive conditions, generally, it is important to preserve the freshness of the products.
In general, there is also the problem that is called low temperature damage while storing, so it is also necessary to pay attention to this.
It is compulsory to control the complete cold chain, vegetables categories are generally chilled at 2～10°C.
Out of this range, the chances for the products to be derefrigerated will be high, and the price of the product will be decreased as well. In the case of storing vegetables and fruits, it is really necessary to pay attention to the fact that for each product type, their respective optimum temperature, humidity and environment gas differ.
Depending on each case, machines like CA11 storages that adjust the composition of environmental gas are important.
In the case of mixed loading, it is necessary to be careful if the volume of ethylene gas emission from the products is high and may affect other product.
Moreover, the same attention should also be paid to those products which are easy to get low temperature damages.
Mixing these kinds of products with others should be avoided for long hour delivery.