Commercial FAQ

Technical FAQ

1.   Which is the USP (Unique Selling Proposition) of the PRS Reefer Container?

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.

2.   Does PRS Equipment comply with the Principles of the European Green Deal?

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 Farm-to-Market uninterrupted cold chain: the interaction between Thermal Autonomy and high thermal storage results in the unique capacity of PRS Reefer Containers to be used from the fields to the markets.
  • Direct refrigeration equipment characteristics: energy-saving, CO2 reduction and reduction of weight loss are unique features that no other reefer equipment has.
  • Mode of transportation: the interaction between Thermal Autonomy and the quality of preservation allows a switch from high environmental impact modes such as trucking and airfreight to low environmental impact modes such as sea freight, railway and river navigation.

3.   Which financial benefits can an operator get from PRS Technology?

The main financial benefits for the operator of PRS Reefer Containers are the following:

  • Reduction of operating costs: 81.9% energy saving, no maintenance, handling as dry containers.
  • Reduction of amortization costs: the 15-year life without performance derating proportionally reduces the yearly amortization.

4.   Are PRS Reefer Containers suited for intermodal logistics?

PRS Reefer Containers are the optimal solution for intermodal logistics for the following main reasons:

  • Handling: while conventional reefer containers need to be continuously plugged-in during operations, PRS Reefer Containers do not need power connection after the Thermal Charge and, therefore, are handled as dry containers with related cost reduction.
  • Uninterrupted cold chain: while conventional reefer containers are disconnected from the power supply during handling at intermodal exchange platforms, with the subsequent switch-off of the cooling unit and rapid increase of the internal temperature, PRS Reefer Containers guarantee an uninterrupted multimodal cold chain from In-Field Postharvest to markets thanks to the Thermal Autonomy.

5.   Can PRS Reefer Containers be deployed on the Rail Silk Road?

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.

6.   How is the optimal value of the internal temperature of PRS Reefer Containers achieved?

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.

7.   How are PRS Reefer Containers manufactured?

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.

8.   Which container sizes are available?

PRS SA manufactures the following PRS Equipment, which is used in accordance with the clients’ requirements:

  • Long haul: 20’HC, 40’HC and 45’HC ISO reefer containers.
  • Off-shore: 8’ and 10’ DNV containers.
  • Domestic and last-mile distribution: ISO and EURO Thermopallets, custom Thermoboxes.

9.   Are PRS Reefer Containers suitable for river navigation?

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.

10.  Post-Sale Assistance and Training

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.

11.  How sustainable and eco-friendly is PRS Technology?

The sustainability of PRS Technology and compliance with the principles of the European Green Deal are the results of the following fundamental unique characteristics:

  • 81.9% energy and CO2 savings for refrigeration equipment functioning  

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.

  • 90.7% average energy and CO2 savings for the change of transport mode allowed by the Thermal Autonomy and superior foodstuff preservation characteristics.

The change from the road to railway/river navigation and from airfreight to sea freight allow an average of 90.7% savings.

  • 55% weight loss reduction

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.

  • Reduction of packing and packaging

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.

12.  Which goods are suitable to be shipped in PRS Reefer Containers?

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.

13.  Who are the competitors of PRS?

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.

14.  Has PRS Technology been recognized by International Institutions and Organizations?

PRS Technology has been certified by several Accredited International Institutions some of which are:

  • Italy's Ministry of Agricultural, Food and Forestry Policies (MIPAAF - Ministero delle Politiche Agricole Alimentari e Forestali): Gold Medal for “Novità Tecnologiche per l’Agricoltura”.
  • 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.

  • United Nations Industrial Development Organization (UNIDO): As the “World Best Technological Innovation in Agrifood Business”.
  • Ministry of Industry of the People’s Republic of China: technical, commercial, economic and IP appraisal of PRS Technology and PRS market potential after a two-year appraisal executed by a Team of Experts accredited by the Chinese Government including the National Test Center of Beijing.





Testing of the PRS Reefer Containers was done in Alexandria-Egypt, a location which has moderate climatic conditions. How do we convince clients to use PRS Reefer Containers in moderate to hot environmental conditions?

  • Testing in Egypt occurred in the desert south of Marsa Matrouh. This coastal city doen not exactly has a “moderate” climate, but surely is less hot than other desert areas.
  • Figs were used to conduct this test. They arrived at a temperature ranging from 30 to 42°C.
  • In order to demonstrate thze abilities of the PRS Reefer Container to clients, demo units were delivered.
  • PRS Technology has performances that are not comparable with conventional reefers and cannot be explained in a simple manner due to the complexity that is encompassed, such as:

-  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.


What is the shelf life with the ambient temperatures of up to 55°C?

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.


What happens if we take several hours to stuff/unstuff a product into a PRS Reefer Container?

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.


What happens if the container's Thermal Autonomy is completely depleted if the container has remained under the desert sun for a long period of time?

It is necessary to initiate a Full Thermal Charge.


How long does it take to recharge completely?

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.


What happens if the recharging is stopped before the end?

The Thermal Autonomy will be proportional to the duration/amount of energy of the thermal charge.


What happens if the Thermal Charge is interrupted due to mains failure?

The Thermal Charge will restart automatically when the power returns and will be automatically completed.


During the recharge time is the container maintaining the product correctly?

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.


How do the Thermal Accumulators of the PRS Reefer Containers work?

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.


Sinve the PRS Thermal Accumulator charge is fully automatic, can someone manually make the charge if the automatic system fails? 

Yes, it can be made with the supervision of properly trained personnel.


As the product can be stored in the container for 25 days (depending on the outside temperature), how does this concept really work?

The difference between the Thermal Autonomy and the storage life of the products is the following:

  • Thermal Autonomy: is the period during which the internal temperature is maintained at the rated value without further recharge of the Thermal Accumulators.
  • Storage life depends on the type of products being stored and can range from 25 days for baby leaf lettuce to several months for oranges, artichokes, peaches, clementines, etc.


Which products can be stored in PRS Reefer Containers for 25 days with the outside temperature reaching + 55°C?

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 Reefer Containers claim zero maintenance. Do you mean to say that for 15 years, they can be maintained at the same pace or some type of maintenance is required?

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 lack of forced air ventilation will create “hot spots” due to the heat released by the horticultural products, which is not evacuated by the forced airflow?

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.


In PRS Reefer Containers there is no air exchange between the ambient and the interior of the container, therefore, will the lack of fresh oxygen will “suffocate” the products and cause a faster decay?

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:

  • There were no “hot spots” caused by the interaction between the heat released by the horticultural products and the lack of forced air ventilation which were monitored during the test inside the container.
  • The ethylene concentration produced by the horticultural products inside the container during the test did not cause product ripening.
  • According to the AFAM guide, the measure of CO2 concentration was below the recommended limit of 10%.


PRS claims that the containers can also be used also for In-Field Postharvest product pull down: is this possible because of the lack of forced internal air circulation, which drastically reduces the heat release from the products?

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.