Here is another interesting application of Dymola. The task is to optimize the control strategies for a metro HVAC system with several circuits. 

This study, grounded in a practical metro project, investigates four control strategies for chilled water systems, focusing on chiller sequencing, pump frequency modulation, and variable flow regulation. A dynamic system model was developed using Dymola to simulate and evaluate the performance of each strategy.

Lessons learned were:

• Energy-saving performance: reduced total system energy use by 8.62% by applying a new control strategy.
• Equipment energy profiles: Chillers were responsible for nearly 80% of total system consumption, confirming their central role in HVAC energy use.
• Implications for system control: These results highlight the value of digital, twin–based adaptive control. Unlike fixed-rule strategies, intelligent models can respond to changing environmental conditions in real time. The findings support a broader shift toward data-informed, model-supported control approaches, critical for improving operational resilience and advancing the decarbonization of metro HVAC systems.

The full paper is available at