www. refrigerationandaircon. co. za RACA Journal I October 2025 27
Project and commendable aspect of this project."
The project was executed within an impressively short timeframe, with construction commencing in April 2024 and the store ' s opening occurring just weeks before this discussion. " This rapid completion timeline is notable, particularly for a new, green-built project." Dewing Construction served as the principal contractor, with Engineering Solutions overseeing the refrigeration components and AirFire Solutions managing the airconditioning installation.
Despite the unified nature
Custom built walk around chiller. of the central plant, distinct contractors were responsible for the refrigeration and airconditioning systems, with the interface occurring at the AHUs. " The refrigeration contractor was responsible for the installation of refrigerant piping up to the AHUs, while the HVAC contractor supplied and installed the AHUs along with the associated ductwork and distribution elements." The airconditioning system provides climate control for the entirety of the facility, encompassing the retail area, liquor store and administrative offices. The refrigeration plant serves critical temperature-controlled zones, including the main freezer room, main cold room, perishable goods receiving area, and a range of refrigerated display cases located on the sales floor.
The primary drivers for this innovative system integration were a specific directive from Massmart mandating the use of CO₂ as the refrigerant and a parallel objective to enhance overall energy efficiency. " This project specification was further augmented to include the air-conditioning system within this unified plant. Traditionally, air conditioning was provided by a separate chilled water system. However, the specification for this project was modified to utilise a DX CO₂ system supplied by the integrated refrigeration plant." The successful implementation of a pilot project in Woodmead, Gauteng, which integrated the liquor store ' s air handling unit with the CO₂ refrigeration system, served as a precedent and proof of concept for this comprehensive integration in the East London store.
The advantages of this pioneering integrated system are both environmental and economic. " This approach yields benefits in terms of both energy efficiency and environmental impact. CO₂ refrigerant has a Global Warming Potential( GWP) of one. Furthermore, from an energy efficiency perspective,
we anticipate potential savings in the range of 20 – 25 % on operational electrical consumption." The total cooling capacity of the integrated plant is approximately 1 600kw( split between air conditioning and refrigeration).
The AHUs and refrigeration racks were built and supplied by Heating Centre( HC Group), a key manufacturer possessing the capability to produce CO₂-compatible coils engineered for high-pressure applications, specifically cooling coils rated at a 60 bar design pressure and heating coils rated at 130 bar. To accommodate the high pressures associated with CO₂ refrigerant, stainless steel piping was utilised throughout the system, with K65 copper specified in instances where copper was deemed necessary. The blower coils within the cold and freezer rooms were also sourced from HC. The control system is managed by CAREL, and the compressors are Danfoss Bok semihermetic models.
The implementation of this innovative integrated system presented notable complexities. " The process was certainly not straightforward, requiring significant effort in integration, particularly as a first-of-its-kind application requiring complex control logic. Close collaboration between the refrigeration and air-conditioning contractors was essential," Arnold elaborated.
www. refrigerationandaircon. co. za RACA Journal I October 2025 27