This document is a case study that outlines the process and findings of an energy audit conducted for a chiller plant at a hotel in Rotterdam, Netherlands. The audit aimed to assess the existing performance of the chiller system and provide recommendations for energy conservation and compliance with new energy efficiency regulations. The audit report details the proposed measures, which included replacing the existing chillers with optimized air-cooled scroll chillers and new control systems. The report highlights the expected benefits of these changes, including a projected 72% energy savings and a return on investment of less than three years. Additionally, the audit emphasizes the importance of reducing gas emissions and improving guest comfort through lower noise levels. The document also discusses the broader context of energy consumption in HVAC installations and the impact of European regulations on energy efficiency and greenhouse gas emissions.