RACA Journal February 2024 | Page 18

Feature

current refrigerants being used in various applications , including computer room air conditioning units ( CRAC units ) and chillers . This highlights a potential knowledge gap that suppliers can help fill , offering essential information to consulting engineers grappling with the evolving landscape .

Koeslag emphasises the importance of considering new refrigerants . Specifically , for chillers , options include R-454B and R-513A and for CRAC units , R-513A or even R-1234ze . “ These synthetic refrigerants , though not natural , are currently more practical alternatives , considering factors like safety and cost and their low GWP . While the industry acknowledges the benefits of natural refrigerants , their adoption poses challenges . Explosive options like butane and propane are A3 classified refrigerants requiring further attention on their applications , while ammonia is not considered viable in the data centre industry . Carbon dioxide ( CO2 ) emerges as a promising natural refrigerant , with advancements in CO2 chillers , albeit at a higher cost compared to synthetic equivalents .”

The industry faces a future where even current hydrofluorocarbons ( HFCs ) are set to be phased out . In Europe , discussions about their complete phase-down by 2050 are well advanced . Considering many systems are imported from Europe , this necessitates a shift toward natural refrigerants , but their widespread adoption is still in its infancy in South Africa .

When queried about HiRef ’ s involvement in researching natural refrigerants , Migliore affirms ongoing research and development ( R & D ) efforts . The company is actively engaged in developing equipment that supports these new refrigerants and there ’ s relentless R & D undertaken at the company ’ s proprietary laboratories in their Padova-based manufacturing facility .

Koeslag underscores the importance of adaptability in choosing a cooling system : “ With a variety of refrigerants , we cater to diverse heat pump requirements , reaching up to 120 ° C . This is especially relevant in Europe , where a shift from gas boilers to heat pumps is underway , aligning with the broader push towards sustainability .”

Another concept popular in Europe – in some cities even mandatory – but not likely to be seen in South Africa due to the absence of widespread heating infrastructure , is the utilisation of excess energy from data centres for district heating . “ Through heat pumps , this surplus energy can be redirected to local industries or district heating systems .”

Shifting the focus to the data centre ’ s heart , the rack units , Koeslag emphasises the prevalent use of R-513A as a refrigerant . However , a notable trend in South Africa is the increasing adoption of dual-medium units . These units seamlessly integrate chilled water and direct expansion ( DX ) systems , providing a redundant solution for uninterrupted operation .

“ Data centres operate on tiered systems , ensuring N + 1 redundancy . This means having a base load plus an additional unit for backup , safeguarding against failures in chillers or CRAC units and maintaining uninterrupted operations .”