As large common areas, cruise ship atriums affect passenger comfort and HVAC efficiency. Due to their complexity and high occupancy, maintaining a suitable thermal environment is difficult. Experimental measurements, thermal load analysis, and CFD simulation are used to assess and improve the atrium’s summer thermal climate. Experimental data supported the use of the RNG $k$-$\epsilon$ turbulence model to forecast airflow and temperature. To meet the cooling demand of 28,784 W, a supply air volume of 10,742 m³/h was required. Various air-supply methods were evaluated for temperature distribution, airflow velocity, PMV, and air age. Larger diffusers and better air dispersion increased temperature homogeneity, air age, and comfort. Redistributing airflow to corridors reduced localized overheating but raised core temperatures, whereas adding diffusers without boosting supply volume caused interference. The configuration with larger diffuser areas and equilibrated airflow maintained a temperature of 21–23 $°\mathrm{C}$, a PMV of −0.1 to 0.1, an air velocity of 0–0.3 $\mathrm{m}/\mathrm{s}$, and an average air age of 350 s. The findings provide theoretical and engineering guidance for energy-efficient HVAC systems in cruise ship atriums and other large public spaces.

The overall center of gravity (CG) position of large marine structures is a key parameter for offshore engineering equipment, as it directly affects dynamic behavior, stability, marine transportation safety, and float-over installation operability. This study develops a segmented hybrid weighing methodology according to the configuration and modular fabrication characteristics of large offshore structures. Building on the principles of multi-point weighing and the inclining experiment method, the procedure enables an accurate experimental determination of a structure’s weight and CG. A case study on an example structure is conducted, in which full-scale weighing tests are performed and the measured weight and CG are benchmarked against finite element analysis predictions and as-built weight control records (ANSYS Workbench 2022R1). Compared with the construction-stage weight-control record, the measured weight differed by only 1.29 t, corresponding to approximately 0.07% of the reference value. The CG deviation was kept within 1% for the tested structure. Discrepancies are quantified through error analysis, verifying the reliability and practicality of the proposed approach. The method addresses two persistent challenges, insufficient CG accuracy and the difficulty of measuring very large structures and provides a robust basis for marine transportation planning and float-over installation of floating offshore structures.