Rising rack and power densities are driving significant interest in liquid cooling for many reasons. Yet, the suggestion that one size fits all ignores one of the most fundamental aspects of potentially hindering adoption – that many data centre applications will continue to utilise air as the most efficient and cost-effective solution for their cooling requirements. The future is undoubtedly hybrid, and by using air cooling, containment, and liquid cooling together, owners and operators can optimise and future-proof their data centre environments.