Improving Ship Energy Efficiency Through Advanced HVAC Simulation Techniques

This study introduces a new dynamic simulation tool designed to analyse the impact of transient operating conditions on ship thermophysical elements and HVAC systems. The tool allows for the evaluation of thermal demands and energy requirements across various thermal zones on the vessel, aiding in the efficient design of HVAC systems and the assessment of energy performance under different configurations. Additionally, it can be implemented as a digital twin on ships equipped with appropriate sensors, enabling real-time optimization of energy use and facilitating rapid evaluations of energy, economic, and environmental impacts for various plant configurations. The approach involves developing a comprehensive 3D model of the ship, which is linked to an energy simulation tool, and incorporating real-world cruise data such as load profiles, hourly weather conditions, and the vessel location and orientation. A proof-of-concept is presented for a medium-sized ship (300 meters in length, 34 meters in width, and 46.2 meters in height), with 16 decks and 6 primary structural zones. The ship energy model includes 1595 thermal zones and accommodates 1750 passengers and 880 crew members. A reference case scenario using an all-air HVAC system is considered, and the effects of five independent and six combined interventions to improve energy efficiency are explored. Key findings indicate fuel savings of 4.11% (equivalent to 0.0546 tons per year) from reducing setpoint temperatures, and up to 32.7% (0.447 tons annually) by combining temperature reconfiguration with variable external air supply. This methodology provides a useful tool for analysing the energy performance of existing systems and testing innovative technologies or strategies onboard modern ships. © 2025 IOS Press.