RACA Journal I January 2026 www. refrigerationandaircon. co. za 21
DATA CENTRE FEATURE SERIES
Image supplied by Lenovo Infrastructure
• The Data Centre Bunker: Utilising disused tunnels, bunkers or transport systems, the Data Centre Bunker places the technology underground to minimise the need for new spaces to increase capacity. This reduces land use while allowing for facilities to be set up in central locations with a lower impact. Benefitting from enhanced security resilience, the subterranean location creates a naturally efficient heat management system.
DATA CENTRES FACE A COOLING CRISIS AS AI DEMAND SURGES
By Dean Wolson, general manager: Africa – Lenovo Infrastructure
As AI workloads drive unprecedented power densities, with racks drawing 20 – 100kW or more, cooling shifts from a supporting role
Dean Wolson, general manager: Africa- Lenovo Infrastructure. to a frontline constraint. For South Africa and much of Africa, this is magnified by high ambient temperatures, a historically unstable grid and rapid growth in cloud and AI infrastructure. While the continent’ s per-capita data centre electricity use remains below 1kWh per person today, it is projected to double by the end of the decade, with South Africa leading the surge in demand as the hub for hyperscalers and sovereign AI projects.
This is the thermal tipping point: air cooling, once good enough, can no longer scale to handle the energy intensity of AI’ s future, particularly in Africa’ s climate and grid context.
Air cooling has been the industry default for decades because it’ s simple and cheap at low power densities. But when rack power draw jumps into the tens or hundreds of kilowatts, as AI-optimised racks do, air becomes inefficient: the temperature delta required gets larger, fans and CRAC units consume more power, and thermal throttling risks increase. Research and market analysis across 2023 – 2025 show an industry pivot toward liquid cooling, direct-to-chip or immersion, because liquid moves heat far more efficiently than air and reduces total facility PUE( power usage effectiveness).
Air-cooled systems can support up to approximately 70kW per rack in the data centre, but hit a physical limit when it comes to removing heat, known as‘ specific heat capacity’. Beyond this, operators need to look at alternative cooling methods. Adding to the complexity is the rise in demand for AI workloads across every industry, requiring five times the amount of power. The industry is now seeing a shift from chips operating at 120 watts to 600 watts or more.
AFRICA AND SA’ S FOOTPRINT TODAY Per-capita data centre electricity consumption in Africa remains low today, the IEA notes. Africa had less than 1kWh per person of data centre electricity consumption in 2024, but is expected to roughly double toward the end of the decade as cloud adoption, hyperscaler investments and sovereign AI projects scale up. Market research firms place Africa data centre power and cooling markets as high-growth segments in 2024 – 25, signalling rapid investment but also rising on-site power demand.
South Africa is the regional leader in capacity and the obvious hub for hyperscaler and local large-scale deployments. Yet its grid has long operational constraints: coal still supplies the majority of electricity, and historically unstable supply( load-shedding) and rising peak demand have been persistent issues, though there were signals of improvement in 2025; the structural challenges remain. This combination of rising local demand from data centres, heat-intensified cooling loads and a constrained, carbonintensive grid is why the cooling question is particularly acute in South Africa.
Higher ambient temperatures mean air cooling must work harder. In warm climates common across much of sub-Saharan Africa, the capacity margin available to dissipate high-density AI heat loads using air is much smaller than in temperate zones. That raises two problems. Higher operational costs, which means more fan and compressor energy, and a higher probability of hitting physical thermal limits that force performance throttling or prevent deployments altogether. Ember’ s 2024 – 25 electricity reviews show heatwaves already boosting residential A / C demand, meaning data centre cooling will compete more directly with other priority electricity uses.
WHAT SCALABLE ALTERNATIVES AND MITIGATIONS LOOK LIKE To avoid hitting the thermal tipping point, Africa’ s data centre industry will need a mix of innovations and policy support. The first is liquid cooling adoption, whether direct-to-chip or immersion, which has been proven to reduce cooling energy and enable far higher rack densities, essential for AI-heavy facilities. Second, operators must embrace on-site generation and co-located renewables, especially solar plus battery systems, which can ease peak grid loads and provide resilience against outages, a strategy that aligns with Africa’ s accelerating solar boom.
Data centres
RACA Journal I January 2026 www. refrigerationandaircon. co. za 21