By Eamonn Ryan
Cool Reaction’s cutting-edge cold room project for Plennegy was focused on optimising energy efficiency and storage capabilities.
Design specifications were for a seed storage cold room of 3 600m² with Relative Humidity (RH) of > 45% and a temperature range of 10-14°C with a monitoring system, as well as fire detection and automated sliding doors. Fire detection provided some technical difficulty which was solved with mechanical smoke extraction with drop out panels.
Graham Bloom, owner of Cool Reaction – who was the project manager who performed the function of consulting engineer informally – was actively involved in the refrigeration side of the project.
Bloom explains: Plennegy is the owner or Starke Ayres, which owns the entire site. Plennegy’s client is Corteva Agrosciences a division of Dow DuPont (US), with the latter renting space from Starke Ayres for seed storage. “Cool Reaction has had a long-term relationship with Starke Ayres. Over the past years we have successfully completed many projects for them, locally and in Africa, most recently Mozambique.
“We were commissioned by the Plennegy Group to find a solution for energy efficient refrigeration equipment for 3 500m2. The physical room size was 100m x 35m sloping from 12m to 8m in height and was supplied by Dalucon. The required capacity of the refrigeration equipment was 525 kW.”
“What is unique about the project,” says Bloom, “is that the cold facility has not been installed inside a warehouse – the roof and side walls are polyurethane injected chromodek.”
Cool Reaction approached Daikin for a solution for the project and they worked together in coming to a conclusion. Cool Reaction was responsible for the supplying, installing and commissioning of all the refrigeration equipment, the Munters dehumidification systems and the electrical control wiring. “We supplied 450m of heavy-duty cable ladders in order to support the hanging of 40 evaporator coils and to run the refrigerant piping. Steel structures were built to house 14 condensing units and two dehumidification plants,” adds Bloom.
The refrigeration installation consisted of hanging the evaporator coils, the placement of the condensing and the dehumidification units including all galvanised duct work and R410 copper piping. Daikin assisted in the commissioning of all systems.
The electrical control wiring consisted of wiring of the control system which is used for monitoring and changing of settings and parameters where required. Cool Reaction was also involved in supplying and fitting of electrical gate motors for opening and closing of the cold room sliding doors. “The air curtains were fitted by our teams above each door using motion sensors to switch on and off,” he says.
“With the hard work of Cool Reaction’s committed teams, we were able to complete this project within 3.5 months. We are exceptionally proud of our teams for their high-quality work which resulted in the success of the project,” says Bloom.
“It was a pleasure working with the following companies: Plennegy, our client; WFW Steel Works, who assisted with all structural work and fitment of insulated room panels; Dalucon. our supplier and manufacturer of the of chiller/freezer room; Daikin, our supplier of the ZEAS condensing units; Advance Electrical, who were responsible for the electrical panels; Keystar, the supplier of the control system; and Colcab for the evaporator coils.
Project challenges
The project commenced in September 2022 – when Simon Pride gave the go ahead – and completed 16 March 2023. Commissioning is currently underway. While the project went ahead smoothly, there were a number of challenges to be faced: The first was a substantial two-year waiting period on the project, derived primarily from the delayed clearance from the US-based holding company of the client. This in turn delayed plan approval from council. The second was more local in nature: the challenge of establishing a reliable and adequate source of electricity, which is under investigation at the moment to supplement with solar energy. A third was excessive rain which hindered work.
Frank Butler and Ernest Hoddinott of WFW Engineering were involved on the project’s structural work from the outset. Hoddinott says: “Corteva is a seed distributor, so the basis for the cold room was the need to keep the temperature of the warehoused seed stock controlled at a range near 10°C and humidity conditions above 45% for extended periods of time. Maintaining the ideal RH is essential to prevent germination or spoilage. To achieve these precise parameters, meters for dehumidification have been integrated into the design. RH refers to the amount of moisture present in the air compared to its saturation point.
“The warehouse building itself came with the challenge of requiring an enormous amount of backfill soil, approximately
7 000m3, to get the site level,” he adds.
The cold room incorporates 14 Daikin condensers and Munters dehumidification plant with an impressive array of 40 Colcab evaporator coils inside the room. These components were carefully selected to meet the project’s objectives, which was primarily optimal energy efficiency, says Bloom.
“Daikin is well-versed in European refrigeration projects which is why we opted to collaborate with experts in the field to ensure the project’s success.” Daikin, as a key collaborator in the project, has played a significant role in providing essential equipment. Their expertise lies in offering customised solutions tailored to specific applications.
“The cold room comprises seven condensing units, of which six are slightly bigger than the last one and are interconnected with three evaporator coils each inside the facility. This arrangement results in a total of 18 evaporators and the last two evaporator coils on the one side are a mirror image configuration working off the smaller, seventh evaporator. This ensures efficient cooling throughout the space, while a smaller condenser unit complements the overall system.”
As a result of the energy debacle, the project’s anticipated operational timeline remains a subject of discussion and the warehouse is still being commissioned. “As of now, its current status is not yet at full operational capacity. However, diligent efforts are underway to ensure a successful completion,” says Bloom.
Building Management System (BMS)
Marcus Lefawane, the on-site service engineer for Daikin’s condensers, ensures the proper functioning and maintenance of the cold room. He explains that the BMS screen shows what each unit is doing, its current temperature and defrosting schedule.
Colcab’s coils are an essential feature of the cold room project to optimise performance and functionality. Daikin also provided the IP unit which facilitates communication between Keystar BTX 600 Building Management System and the refrigeration units. By providing an IP interface, they enable the units to communicate seamlessly with the customer’s preferred BACnet Modbus BMS system.
The integration of the BMS with the refrigeration units offers facility managers invaluable information to monitor and control the cold room’s operations. The BMS presents various data points, allowing managers to gain real-time insights into the unit’s performance. This includes temperature differentials, unit statuses, defrost cycles, and more.
Automation plays a vital role in the cold room’s functionality. When the temperature deviates from the desired range, the units are programmed to initiate protective measures, such as defrost cycles, to safeguard the stored goods. This automation reduces the need for constant manual intervention, ensuring smooth and uninterrupted operations.
Daikin ZEAS outdoor refrigeration condensing units
Michael Olivier: Daikin South Africa service engineer says: “Daikin was approached by Graham Bloom from Cool Reaction for a refrigeration solution for a cold storage facility, the requirement being for an energy efficient modular system that has full monitoring capability.
“Graham has previously used the Daikin VRV equipment and was looking to trial the refrigeration version of the tried and tested technology. The cooling load was to be spread across 40 evaporators wherein Daikin equipment selection and layout was done by consulting sales engineer Nico Van Heerden; it was decided to match up the 40 evaporators to the Daikin ZEAS refrigeration condensers. The following equipment was used: 12 x LREQ20BY1 and 2 x LREQ12BY1. Controls and monitoring were done using Eliwell equipment supplied by Keystar,” says Olivier.
“Each of the systems can be individually controlled both in the facility and remotely giving the client both peace of mind and total control over its facility. Daikin and Keystar assisted Cool Reaction with the commissioning of the site and was successfully completed.”
Designed with its signature VRV technology and inverter technology, Daikin ZEAS condensing units cut energy consumption by 10 to 35% when compared to traditional refrigeration systems. In certain instances, it even surpasses the 35% saving, says Olivier. “Combined with our economiser technology, ZEAS condensing units are more efficient, last longer and perform at a higher capacity than other solutions on the market,” he claims.
”ZEAS units are factory-assembled and its reduced footprint makes installation in small spaces easy. Its modular design maximises installation flexibility because you can group outdoor units in blocks or rows, or rather distribute them around the building based on your needs. The built-in controls and automated optimisation features allow you to install a ZEAS unit as a plug-and-play solution. With the best surface-to-capacity ratio on the market, it also provides you with enormous savings in terms of space.
“A big thank you to Graham and his team for successfully completing and commissioning the installation, the installation was of high quality and the commissioning process was a breeze. Looking very forward to many more projects with him and his team,” says Olivier.
The RTX 600 V Domino Zero
Ben Milne, WC Manager: Keystar Industries | Eliwell by Schneider Electric, says: “Using the latest RTX 600 V Domino Zero to control the 40 evaporator PWM valves servicing this very large cold room space, we are able to obtain precise superheat and temperature control – allowing for stable suction conditions back to the Daikin ZEAS units.
“Hand in hand, it is an excellent combination of electronic modulation, between evaporator and compressor. Aimed at achieving a perfect balance, it respects the safeties of the compressor to ensure its longevity while achieving pinpoint temperature control,” says Milne.
“RTX 600 V Domino Zero Electronic Expansion valve control has about 50 configurable parameter settings and options purely dedicated to fine tuning the valve control for the above purpose – should one of the eight pre-set cabinet / room default programme applications need adjustment.
“On top of a vast variety of defrosting options on RTX, the temperature alarm functionality is also flexible, to suit any application. It is critical to ensure that the product is protected and watched over, should a failure occur. All 40 RTX controllers are linked back to the TelevisGo monitoring system, keeping eyes on every section of the room.”
Milne explains that TelevisGo is monitoring about 20 different alarm conditions from each RTX, and with its Modbus capabilities. “Eliwell and Daikin have worked hard to create software enabling us to view the conditions and alarm values from each ZEAS unit.
“TelevisGo is capable of filtering the hundreds of different alarm values from multiple devices, and then based on a programmable time zone we are able to action the alarm condition. It is important not to desensitise the end user from what is a critical alarm and what is a nuisance warning.
“It is quite challenging to manage and find the balance between the two. On the one hand you need to protect your product and in an emergency scenario, act accordingly… On the other hand, you want to perform preventative maintenance so every warning or alert that the system produces should also be considered,” adds Milne.
Dalucon Refrigeration Products
Dalucon says it was commissioned to manufacture and install its quality insulated polyurethane panels for Plennegy. In a provided statement it said it was privileged to “manufacture cold and freezer rooms, partitioning walls as well our IBR roofing panels, various doors, from sliding to fire escape doors for this facility. With our versatile product that is the heart of our company, founded by Aldo Martinelli in 1991, with a combined company knowledge of over 50 years.
“With four presses fully functional, we can produce high pressure injected polyurethane insulated panels from 2.5m in length up to 16.5m in length with no joints. Producing 16.5m insulated panels makes Dalucon Refrigeration Products the first in its class, the only company in South Africa, to provide customers with this high-end product. Dalucon would like to thank Plennegy for the opportunity, trust and partnership throughout this project.”
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