www. refrigerationandaircon. co. za RACA Journal I August 2025 31
Project
STELLENBOSCH UNIVERSITY EMBARKS ON AMBITIOUS PRECINCT- COOLING HVAC UPGRADE
By Eamonn Ryan, with technical input from David Lombard, managing director of Lombard Consulting Engineers and Nicol le Roux, technical director at TOAC
Stellenbosch University( SU) is undertaking a significant overhaul of its heating, ventilation and air conditioning( HVAC) infrastructure, with a strong emphasis on enhancing energy efficiency and streamlining maintenance procedures.
University of Stellenbosch chilled water pipes.
This ambitious project was undertaken by Lombard Consulting Engineers and contractor Two Oceans Air Conditioning( TOAC).
Initiated in late 2018, it centres around the installation of a powerful 6 000-kilowatt chilled water plant with reticulation, designed to serve six buildings within the university’ s engineering complex. The project is still ongoing with the full integration of all planned buildings.
The decision to provide air conditioning to buildings that previously lacked it reflects the university ' s commitment to maintaining high standards and remaining competitive with other leading institutions. The underlying rationale is to create a more conducive learning environment and align the university ' s facilities with contemporary standards. Among older universities it was common practice for secondary lecture halls to be unairconditioned, with some over the years having had air conditioning installed on an ad hoc basis with split wall units and the like.
The initiative was driven by the university ' s proactive approach to facility management, responding to the challenges posed by an ageing and increasingly complex HVAC infrastructure. As David Lombard, managing director of Lombard Consulting Engineers – the consultants on the project- explains:“ The university ' s previous reliance on individual split units and Variable Refrigerant Volume( VRV) systems across its buildings had led to an escalating maintenance burden, particularly concerning refrigerant leaks and the availability of spare parts for older VRV generations. This upgrade to a centralised plant aims to consolidate the HVAC infrastructure, eliminating the need to maintain numerous smaller units dispersed throughout the campus.”
At the heart of the new system lies a high-efficiency chilled water plant featuring state-of-the-art Carrier 19DV watercooled variable speed centrifugal chillers. These machines boast impressive Coefficients of Performance( COP), reaching up to 6.5 at full load and potentially 13 under optimised partload conditions with strategic condenser water temperature management. Complementing the chillers are high-performance BAC cooling towers, ensuring efficient heat rejection.
The system ' s design incorporates a large primary loop distributing chilled water to the various buildings, with secondary pumps within each building managing localised distribution.“ The supply of key components has been secured through established industry leaders.” Apart from Carrier being the sole provider of the high-efficiency chillers and BAC supplying the cooling towers; Wilo pumps for the system are sourced from Western Cape Pumps.
Notably, the project also incorporated existing Carrier aircooled chillers, which were only a year and a half old, which were relocated into the main plantroom. One was a heating-cooling machine, and the other and a heating-cooling machine with heat recovery, the latter used to provide hot water and save electricity.
www. refrigerationandaircon. co. za RACA Journal I August 2025 31
Image by Two Oceans Air Conditioning.