Image by Two Oceans Air Conditioning. Image by Lombard Consulting Engineers. www. refrigerationandaircon. co. za RACA Journal I August 2025 35
Project
The project ' s implementation is strategically divided into two near-identical phases in terms of equipment capacity. This phased approach allows for a gradual integration of buildings onto the new system, aligning with their individual refurbishment or construction timelines. As explained by Nicol le Roux, technical director at TOAC, the first phase involved the installation of one large Carrier 19DV chiller, along with its associated pumps, cooling towers and other necessary accessories. This initial phase successfully brought cooling and heating capabilities to the first two buildings( nonairconditioned) which have been operational now for over a year. These two required complete gutting and redesign.
The second phase, completed in May 2025, mirrors the first phase with the installation of a second large Carrier chiller. This was to enable the connection of the remaining buildings to the central plant. A significant design consideration was ensuring seamless integration between the phases. The engineering team proactively incorporated tee pieces with valves and stoppers in the initial phase, allowing for easy future connections without the need for system shutdowns or extensive modifications to existing pipework.
Until that moment, buildings not yet connected to the central plant continued to utilise their legacy air conditioning systems, which in some cases involved temporary loan chillers due to the earlier failure of older building-integrated units. As the remaining buildings underwent refurbishment and their internal HVAC systems were upgraded, they were progressively connected to the central chilled water and heating hot water loops. Buildings refurbished more recently primarily required the installation of secondary pumps to interface with the new central plant.
The installation phase of a project of this magnitude inevitably presents its own set of challenges. TOAC’ s Le Roux highlights the complexities of handling and installing large-diameter( 350mm and 400mm) steel piping, requiring specialised welding in confined spaces. The sheer size and weight( 14 tons) of the Carrier 19DV chillers also posed significant logistical hurdles in rigging them into the plant room. Adding to these challenges was a minor oversight during the plant room ' s initial construction, where a door opening was inadvertently made smaller than specified due to an existing structural beam, requiring careful and time-consuming manipulating of the massive chiller unit.“ Much of the equipment was on the roof and had to be carried up three floors – but this is nothing we’ re not used to.”
Despite these challenges, the collaborative approach between the consulting engineers and the contractors, coupled with meticulous planning and foresight in the system ' s design and phasing, is ensuring the successful implementation of this ambitious and technologically advanced HVAC infrastructure
A 3D rendering.
Another view of the chilled water pipes.
upgrade at Stellenbosch University. The project promises not only enhanced comfort and efficiency but also a more resilient and maintainable system for the future.
FORWARD-THINKING VISION DRIVES SU PROJECT Both Lombard and Le Roux emphasise that overcoming logistical hurdles is inherent in projects of this magnitude. As Le Roux points out, the two-megawatt-plus cooling capacity Carrier behemoths are relatively rare in South Africa, with the supplier typically bringing in only one or two such units each year.
Unlike more usual strategies that address HVAC issues on a building-by-building basis, this precinct-wide model demonstrates a commitment to long-term efficiency and standardised comfort across multiple facilities. While termed‘ district cooling’ colloquially, Lombard clarifies that the SU project is more accurately described as a‘ precinct’ cooling and heating system, serving a concentrated area of campus buildings.
In conclusion, Stellenbosch University ' s HVAC upgrade is not just a replacement project; it ' s a strategic investment in a futureready infrastructure characterised by high-efficiency technology, robust redundancy and a visionary approach to campus-wide comfort and sustainability. The successful implementation of these massive chillers and the phased integration of buildings mark a significant step forward in the university ' s commitment to providing world-class facilities. RACA
Image by Two Oceans Air Conditioning. Image by Lombard Consulting Engineers. www. refrigerationandaircon. co. za RACA Journal I August 2025 35