It usually takes 1-2 hours. At a minimum, it must take 30 minutes. Both the pre-cooled trailer and the truck need to have enough time to prepare for the next shipment, otherwise, the inside of the reefer will be too hot to use for transporting goods. Be sure to keep yourself in mind exactly how much time is needed.
What factors affect refrigeration?
Whether you have a trailer or a box truck, it is subject to various aspects, which affect the cooling effect. He is a combination of reasons, subject to internal causes and external factors, usually related to temperature and body materials, space, refrigeration components, etc.
External environmental factors
Ambient temperature
The higher the external temperature, the longer the cooling time, especially in summer or hot areas. If the external temperature is too high, it may be necessary to pre-cool the vehicle 2-3 hours in advance to prevent conditions such as elevated temperatures during shipment.
Humidity
High air humidity may cause the condenser efficiency to decrease, it will need to increase the pre-cooling time, otherwise the cooling efficiency will become much worse.
Solar radiation
During sunny weather, the sun’s rays are generally long and a lot of heat is directed to the truck, resulting in an increase in temperature, which will rise very quickly if the compartment is made of aluminium or steel. Nowadays, with fiberglass XPS foam panels it is possible to have excellent thermal insulation with a high thermal conductivity.
The performance of the equipment itself
Power and efficiency of the refrigeration unit
The high power of the refrigeration unit allows more heat to be transferred in a shorter period of time, which results in a quicker temperature drop, and the desired temperature can even be reached in less than an hour.
Therefore, it is very important that the power of the refrigeration unit must match the volume of the cargo compartment, if the power is relatively small, it will easily lead to unstable temperature changes, or even unable to achieve the desired temperature.
Insulation performance of the compartment
The material and thickness of the carriage structure and insulation layer determine the thermal insulation effect. Poorly insulated carriages take longer to cool down. And it will consume more fuel.
Sealing of refrigerated trucks
The integrity of the door seals and the tightness of the seams of the compartment will directly affect the temperature loss. Doors that are opened and closed frequently need to be checked regularly for sealing performance. Seals are usually made of rubber, but if they age, they will become less soft, they will become hard, and they will crack, leading to a reduction in the sealing performance, and ultimately allowing cold air to escape. It must need to be checked regularly.
One thing to note: usually you need to observe the bottom of the trailer for leaks, if there are leaks, then you need to remedy them in time or replace them with brand new FRP XPS panels for the truck body.
Why you should buy or replace FRP foam Panels for refrigerated truck box?
Cold air distribution system
The air circulation inside the cargo box is going to affect the cooling efficiency. When the air duct is not reasonably designed, it will lead to slow cooling speed and also lead to uneven temperature, scientific design of the air duct can ensure that the cold air is evenly distributed to every corner of the compartment, to avoid overcooling or overheating.
The number of air vents is not the more the better, it needs to be in accordance with the actual size of the cargo box layout. If the airflow is very large, it is not always helpful for the transportation process, if the transportation is flowers, vegetables, etc., then it will lead to damage to the goods.
Cleaning: The cold air distribution system needs to be cleaned regularly, such as the fan, air outlet and other places, the dust needs to be cleaned regularly. Otherwise, it will affect the airflow.
