By Albert van Rensburg, engineer
A state-of-the-art cold storage facility in Port Elizabeth enhances agricultural efficiency, supports exports, and utilises sustainable CO2 refrigeration.
In response to growing agricultural demands and logistical challenges in Port Elizabeth, a state-of- the-art cold storage facility was developed to serve as a vital link for local fruit farmers and export businesses. The greenfield project, which began in 2020 and concluded in August 2024, aims to enhance operational efficiency and provide sustainable refrigeration solutions for the region. Featuring advanced CO2 refrigeration technology and a flexible design, the facility not only supports the local agricultural sector but also alleviates congestion at key harbours, positioning it as a game-changer for the cold storage industry.
Port Elizabeth identified a significant need for an independent cold room to serve as a vital link for local fruit farmers throughout much of the year. This facility plays a crucial role in mitigating the impact of wind conditions in the region and supports the growing volume of fruit exports. Additionally, from a frozen storage perspective, the cold room will benefit import-export customers by alleviating congestion at the Durban and Cape Town harbours.
Equity and debt funders encountered challenges in securing financing for the project due to its greenfield nature. Many potential customers were only willing to commit to short-term contracts, a common practice in the cold and freezer storage market. Additionally, the site development plan approval process complicated progress, particularly as the three properties involved had not yet been transferred from the seller or consolidated for building plan approval. These factors created significant hurdles for funders looking to invest in the project.
The facility’s requirements were based on projected and future off-take in the region. To effectively serve a larger market with a diverse range of services, the design specifications called for multiple rooms capable of operating at either cold temperatures (around 0°C) or freezer temperatures (approximately -18°C). Initially, each room was designed to function at one of these temperatures. However, during construction, this approach was revised to allow all rooms to accommodate both temperature settings. To manage capital investment, the sterile rooms were initially excluded from the development plan, with plans to add them later. Ultimately, these rooms were reintegrated into the design to meet the industry’s growing sterilisation demands.
At the outset of the project, a decision was made to implement a CO2-based refrigerant system, utilising technology already in use in several large-scale facilities across South Africa. This choice aligns with the global trend towards adopting CO2 refrigeration systems, which are recognised for their environmental benefits. CO2 is a natural refrigerant with low global warming potential and ozone depletion potential, making it an attractive option for businesses focused on sustainability.
The transcritical CO2 systems are particularly well-suited for warm climates, offering energy savings and operational efficiency. These systems incorporate advanced design features such as adiabatic gas coolers and sophisticated control systems to ensure reliable performance even in high ambient temperatures. As industries increasingly prioritise eco-friendly solutions, the adoption of CO2 refrigeration technology is expected to grow, positioning it as a leading choice for future refrigeration needs.
CO2 refrigeration systems are increasingly recognised for their energy efficiency and sustainability, making them an attractive alternative to traditional refrigerants.
Energy efficiency
CO2 systems offer superior energy efficiency, particularly in cooler climates where they can achieve high Coefficient of Performance (COP) values. These systems are designed to operate effectively even at higher ambient temperatures; however, their efficiency may decline in extreme heat due to CO2’s critical temperature of 31°C (87.8°F). Innovative technologies, such as pressure exchangers, have been developed to enhance system efficiency, especially in warmer conditions, by improving stability and reducing energy costs.
Environmental benefits
- Low global warming potential (GWP): CO2 has a GWP of 1, significantly lower than many synthetic refrigerants, which can have GWPs in the thousands. This feature helps mitigate climate change impacts associated with refrigerant leaks.
- Non-toxic and non-flammable: CO2 poses minimal health risks and is safe for use in various applications, including food storage.
- Ozone depletion potential (ODP): CO2 has an ODP of 0, meaning it does not contribute to ozone layer depletion.
These attributes make CO2 a preferred choice under regulations aimed at phasing out harmful refrigerants. CO2 refrigeration systems represent a significant advancement in sustainable cooling technology. Their energy efficiency and environmentally friendly characteristics position them as viable solutions for reducing the carbon footprint of refrigeration processes. However, careful attention to design and climate-specific performance is necessary to maximise their benefits across different applications. As industries move toward decarbonisation, CO2 refrigeration systems are expected to play a growing role in achieving these goals while ensuring operational efficiency.
The cold room is designed for flexibility, operating independently to serve dual purposes as both a freezer and a chilled storage area. It is equipped with eight sterile rooms and eight dock levellers, ensuring efficient loading operations. The facility is built to accommodate high demand, particularly during peak seasons such as citrus harvests, when it operates 24/7. This adaptability and continuous operation during critical periods make the system and installation particularly unique and well-suited to meet the fluctuating needs of the industry.
Matador’s engineered design, technological flexibility and advanced control systemsBy Eamonn Ryan, with technical input from Brent Duffield and Chris Vorster of Matador Refrigeration The Port Elizabeth cold storage facility is a prime example of how modern refrigeration technology and adaptive design by Matador Refrigeration can reshape the food storage industry. Designed with operational flexibility in mind, the facility employs a sophisticated transcritical CO2 refrigeration system, allowing it to toggle seamlessly between different temperature ranges to accommodate a variety of storage needs. Brent Duffield, Matador Refrigeration managing director, says: “The project initially began as a simple cold storage solution but quickly evolved as the needs of the business evolved. The facility’s design was adjusted to include both medium and low-temperature storage capabilities – changeable at the flick of a switch. This change required engineering ingenuity to ensure that the system could be reconfigured to serve multiple temperature zones, depending on the type of produce being stored at any given time.” The CCH cold store incorporates four large rooms capable of switching between medium and low temperatures, making it a versatile solution for handling a range of products. The flip of a switch can change the operational mode, adjusting multiple controllers and parameters in the system to deliver either cold or freezing temperatures. This adaptability allows for dynamic response to varying storage needs, whether handling fresh produce or frozen goods.
Hot gas defrost and efficient cold storageChris Vorster, Matador’s engineering manager, adds: “One of the standout features of this facility is its advanced hot gas defrost system, which is used for low-temperature applications. This system allows the cold storage rooms to maintain consistent temperatures by preventing the build-up of ice on the evaporators, ensuring continuous performance even in the most demanding conditions. The hot gas defrost process is controlled through a central system that ensures rapid and efficient defrosting, minimising energy consumption and downtime during the defrost cycle.” Additionally, the facility features eight ‘steri-rooms’, designed specifically for the critical drop temperature process. When produce enters the facility, it’s placed in these rooms, where the temperature is gradually reduced over 72 hours from a starting temperature of +20°C to reach an optimal storage condition. This slow cooling process is crucial for maintaining the quality of the produce, especially for export markets with stringent quality requirements. The gradual cooling is managed by a peripheral control board (PCB), ensuring that the temperature drop is uniform and within the specified protocols required for certification in different global markets. The rooms can also double as storage rooms when necessary.
Remote monitoring and automationOngoing maintenance and monitoring are also key components of the facility’s operations. It is equipped with an advanced remote monitoring system that ensures optimal operation. Using a centralised control platform, operators can monitor and adjust the refrigeration system remotely, making it possible to respond to real-time conditions without needing to be physically present on-site. The monitoring system at Matador’s head office in Midrand integrates with the facility’s control room, provides visibility into system performance and alerts operators to any issues, allowing for quick intervention and minimising downtime. If any issues arise, a sub-contracted service team is on hand to respond quickly. The use of CO2 sensors throughout the facility further enhances safety and ensures that any gas leaks are promptly detected and addressed. The flexibility of the system lies in its automation features. When product types or storage conditions change, the system can be reconfigured without requiring manual intervention. Once the desired temperature settings are determined, operators can remotely initiate the changes, adjusting the system’s parameters to ensure that the correct temperature is maintained. This level of automation not only enhances operational efficiency but also ensures that the facility operates in a highly responsive manner.
Sustainable CO2 refrigeration technology“The decision to implement a CO2 refrigeration system in the Port Elizabeth cold storage facility aligns with global trends toward sustainability and energy efficiency in industrial refrigeration,” says Duffield. It was a choice made prior to Matador’s involvement in the project. “CO2, as a natural refrigerant, is non-toxic, non-flammable and has a significantly lower global warming potential (GWP) than traditional refrigerants. This choice reflects the facility’s commitment to reducing its environmental footprint while maintaining reliable and cost- effective cooling – as well as meeting the specifications of European export markets. “The transcritical CO2 system, particularly adapted for warm climates, offers improved energy efficiencies when paired with advanced ancillary components and controls. The system’s performance in high ambient temperatures is optimised by exchangers ensuring the system remains stable and efficient even in extreme conditions.” Vorster adds: “This installation, which features a mix of medium- and low-temperature compressors, aims to optimise both space and energy use. To achieve this, the system places low-temperature compressors on the top of the rack, while medium- temperature compressors are positioned below. The use of hot gas defrost – as opposed to traditional electric defrost – minimises energy consumption and lowers operational costs by utilising the discharge gas from the medium- temperature compressors to defrost the low-temperature coils.”
State-of-the-art componentsThe system incorporates components from top-tier global suppliers, including Danfoss-BOCK for compressors, Swep of Sweden for plate heat exchangers, Colcoil for forced air heat exchangers and locally sourced pressure vessels from Viola. Control panels are assembled in-house, utilising ABB and Schneider components, while the monitoring and control systems are powered by the CAREL control system. This combination of local and international suppliers ensures the system operates at peak efficiency, with reliable performance for years to come.
Overcoming challenges in installationThe installation of the CO2 transcritical refrigeration system was not without its challenges. The project team faced a range of issues, including shifting specifications, tight working spaces and difficult weather conditions. However, through innovative problem-solving and meticulous planning, each obstacle was effectively addressed. One of the first hurdles came in the form of a design change that occurred after the order for the compressors had already been placed. Initially, the system was designed to use a certain number of compressors, but the client’s needs evolved during the project, requiring an additional nine compressors to be added. This late-stage modification meant that the racks had to be reconfigured to accommodate the extra equipment. The team adjusted the design, ensuring that the new system would still meet performance requirements without compromising on space efficiency. The cold storage plant room posed another significant challenge: limited space. The design required careful consideration of compressor placement, pipe routing and the physical layout of the system components. To maximise the available area, the team made a strategic decision to position low-temperature compressors on the top of the racks, with medium-temperature compressors below. This not only saved valuable floor space but also allowed for more efficient use of the entire plant room. The team also had to ensure that each piece of equipment was easily accessible for maintenance and that the plant room remained organised and functional despite the space constraints. The system’s installation came with its fair share of logistical hurdles. Heavy machinery, compressor units and evaporators – some weighing over a ton – had to be hoisted into place using mechanical hoists and secured with steel structures spanning the entire facility. Finally, the weather added another layer of complexity to the project. During the installation phase, heavy rains caused significant delays, with trucks getting stuck in the mud and worksite conditions becoming hazardous. Despite these setbacks, the team remained flexible and adapted to the conditions, using the downtime to focus on other tasks that could be completed indoors or in areas less affected by the weather. By adjusting the work schedule and maintaining clear communication with all stakeholders, the team managed to stay on track and meet the project’s overall deadline. Perhaps the most important factor in overcoming these challenges was the seamless collaboration between all parties involved. From manufacturers to subcontractors, the team’s ability to adapt quickly, communicate effectively and problem-solve on the fly ensured the success of the project. This coordinated approach, combined with a commitment to quality and efficiency, enabled the team to deliver the refrigeration system on time, despite the numerous obstacles that arose during the installation. Refrigeration system details for the Port Elizabeth processing facility Site Information
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System breakdown
This comprehensive breakdown clearly explains the refrigeration system designed for the Port Elizabeth processing facility. We believe this system will provide optimal performance, ensuring the site’s refrigeration needs are met with precision and reliability.
