PRS SA has developed a unique, worldwide-patented Passive Refrigeration Technology which guarantees, after the Pre-Trip Thermal Charge, an unplugged and uninterrupted Door-To-Door Multimodal Cold Chain with Thermal Autonomy of up to 25 days.
PRS breakthrough Thermo Accumulators maintain an internal reefer temperature of 0 to +4°C during the 25 day Thermal Autonomy, with an external temperature of up to 55°C**.
* Thermal autonomy in ATP conditions after Full Thermal Charge
** The Thermal Autonomy is partially a function of the night and day external temperature. With a daily peak at +55°C the autonomy is 20 days.
The characteristics of PRS Equipment fully comply with the principles of the European Green Deal as no other equipment for the transport and/or storage of foodstuff and/or pharmaceutical products has to date. In particular:
The main financial benefits for the operator of PRS Reefer Containers are the following:
PRS Reefer Containers are the optimal solution for intermodal logistics for the following main reasons:
PRS Reefer Containers are the optimal solution for the operation of the Silk Road from China and Europe as, thanks to their Thermal Autonomy, they guarantee an uninterrupted cold chain without an energy supply for the duration of an itinerary and also do not require refueling and service centers along the journey.
The thermal storage required to cover the rated Thermal Autonomy is the result of the physical principle of the heat of fusion of proprietary eutectics contained in the Thermal Accumulators, which is previously frozen by the refrigerant circulated by the external Smart Thermo Charger (STC) plugged to the power supply. The Full Thermal Charge requires between 48 and 72 hours depending on environmental conditions. The internal temperature control is the result of the interaction between the point of fusion of the eutectics and the structural characteristics of the Thermal Accumulators. Thermostats are not required.
A PRS Reefer Container consists of the integration between an external ISO complying insulated structure and the Thermal Accumulators, which cover one or more internal walls of the container. The insulated floor is truckable and has a flat surface without air channels in order to allow better operation of the forklift and easier cleaning.
PRS SA manufactures the following PRS Equipment, which is used in accordance with the clients’ requirements:
Thanks to Thermal Autonomy, PRS Reefer Containers are the ideal solution for river navigation, because they can be transported without power connection and can be handled at terminals as dry containers. In addition, the superior quality of preservation largely compensates for the longer transit time due to the charging/discharging at the terminals and the intrinsic slower velocity of the barges versus the trucks. The environmental impact, consisting of energy consumption and CO2 production, is reduced by 86%. The operation of PRS Reefer Containers for river navigation will result in the economical requalification of this important service which today, due to the technological limits of the conventional reefer equipment, is limited to the transport of low added-value goods.
The PRS joint-venture in China and Spain, the start of a production and service unit in Italy and the agreement with a multinational group with 86 subsidiaries in 22 countries guarantees the worldwide post-sale assistance and training for PRS Equipment.
The sustainability of PRS Technology and compliance with the principles of the European Green Deal are the results of the following fundamental unique characteristics:
During an official comparative test, a conventional reefer container and a PRS Reefer Container were loaded with identical fresh horticultural products and placed for 25 days near to each other at an external ambient condition in accordance with ATP guidelines:
- PRS Reefer Container energy consumption: 799 kWh equivalent to 425 kg of CO2.
- Conventional reefer container energy consumption: 4’426 kWh equivalent to 2’350 kg of CO2.
The change from the road to railway/river navigation and from airfreight to sea freight allow an average of 90.7% savings.
The reduction of weight loss from harvest to market delivery reduces the need for additional production of foodstuff with subsequent reduction of energy, water, and soil depauperate.
The optimal temperature and relative humidity in PRS Reefer Containers combined with the absence of forced ventilation allow to significantly reduce the need for packing/packaging of fresh food thus proportionally reducing plastic consumption.
Extensive lab and field certified tests have proven that PRS Reefer Containers are suitable for the shipment of all perishable fresh food, in particular organic, as well as medical and chemical products.
Both PRS Technology and production cycle IP are protected by international invention patents and invention patent applications. To date, PRS SA is the only provider of Passive Refrigeration cutting-edge and highly sustainable technology.
PRS Technology has been certified by several Accredited International Institutions some of which are:
MACFRUT: Gold Medal Award in the category of logistics and services for Passive Refrigeration and ozone storage, an Innovation Award assigned in 2016.
European Commission – Easy2Cool Project: Two-year comparative research project focused on the preservation of animal origin foodstuff sponsored by the European Commission and jointly executed with Lincoln University and several European accredited Research Centers.
- The 81,9% energy savings versus a conventional reefer, which is significant less
- The 25-day Thermal Autonomy.
- The storage life of fresh vegetables, such as the baby leaf salad, which is close to one month for a PRS Reefer Container and less than seven days for a conventional reefer.
The quality of preservation with the PRS Reefer Container operated at 55°C ambient temperature conditions is equivalent to global standards, as the performances of the PRS Reefer Containers are not affected by the ambient conditions. The only difference is the Thermal Autonomy, which will be relatively shorter in terms of days.
As tested in Egypt, a stuffing time as high as five hours is very unusual. Because the local farmers in Egypt use pick-up vehicles, they had previously never loaded a container before, and conventional reefer containers cannot be used for in-field postharvest product pull down.
Stuffing/unstuffing of a 40’HC container normally requires less than 30 minutes.
It is necessary to initiate a Full Thermal Charge.
It depends on the type of Thermo Charger, the environmental conditions and the status of the container. The standard Full Thermal Charge in ATP conditions typically requires 48 to 72 hours depending on the environmental conditions.
The Thermal Autonomy will be proportional to the duration/amount of energy of the thermal charge.
The Thermal Charge will restart automatically when the power returns and will be automatically completed.
The Routine Thermal Charge (RTC) can be made with the products already stuffed into the PRS Reefer Container, as the products are kept in optimal conditions.
The Thermal Accumulators behave thermally like an electric battery behaves electrically, with the difference being that an electric battery has a shorter life, loses efficiency after a certain number of cycles, and its disposal is expensive as it pollutes and has the potential to explose. PRS Thermal Accumulators have over a 15-year life, do not lose efficiency, aluminum is fully recyclable at zero cost and are totally inert.
Yes, it can be made with the supervision of properly trained personnel.
The difference between the Thermal Autonomy and the storage life of the products is the following:
All fresh horticultural, meat, flowers and poultry can be stored for 25 days with the outside temperature reaching + 55°C. The only exclusion is relevant for bananas and basil. Fish is conserved very well but for shorter periods (typically 50% more than with the ice in conventional reefers).
PRS Marine and Intermodal Reefer Containers
Maintenance is only relevant for mechanical damages, which typically occur to the structure of marine containers. The maintenance of a PRS Reefer Container is equivalent to that of a dry container as there are no moving parts. The performances of PRS Reefer Containers are not derated over time.
Conventional marine reefer containers
Conventional reefers have a life expectancy of 10 years and in this period, in addition to the mechanical repairs, it is necessary to substitute the compressor and other active components if the standard performances have to be guaranteed. Typically the conventional reefer containers are mainly used for fresh foodstuff during the first 6 years of life. After this period, they are used for the transport of frozen foodstuff.
Conventional intermodal reefer containers
While the power supply for the marine containers comes from the mains (onboard plugs - port plugs - truck genset), the intermodal containers have to be equipped with the diesel generators which provide the electricity to the compressors. All diesel engines require continuous maintenance and have a much shorter life than the compressors do. To guarantee the rated standard performances, their substitution is required after a certain number of hours of effective functioning.
Smart Thermo Charger (STC)
The Smart Thermo Charger requires a normal maintenance of standby compressors, which is much less than that for transport reefer equipment.
The “hot spot test” was performed on a 20’HC PRS Reefer Container fully loaded with 10 pallets of avocados. 72 temperature probes were positioned to monitor the temperature in all points and in particular among the pallet-to-pallet points. The customer has verified that not only was there no creation of hot spots, but the initial temperatures, which were different from pallet to pallet, were progressively uniform.
The lack of air exchange, and therefore the lack of new oxygen, combined with the release of CO2 by the products and their oxygen consumption results in the generation of a naturally modified atmosphere which significantly enhances the preservation of the products as confirmed by all tests where both the analysis of the atmosphere inside the container and the quality of preservation of the products have been superior to conventional containers. In particular:
The product pull-down field tests, comparing a PRS Reefer Container to a conventional reefer container both loaded with the same products at the same temperature, have proven that the PRS Reefer Container pulls down the temperature of the products in a time which is 54% shorter than that of the conventional reefer.
The gas does not have to be changed: after the Thermal Charge, the gas circulates into the Thermal Accumulator.