<p>Indoor ice rinks and ski resorts consume substantial cooling energy to maintain low-temperature environments, making energy efficiency a critical concern. Their unique floor structures, comprising an ice or snow layer and embedded cooling/heating coils, pose significant challenges for thermal modeling. This study proposes a state-space floor thermal model integrated with the building energy simulation tool, DeST, to simulate the dynamic thermal processes and annual hourly thermal loads of such arenas. The integrated model can efficiently handle the coupled heat and mass transfer between the floor frozen layer and the indoor air, and accurately calculate and distinguish the thermal loads borne by floor cooling coils, floor heating coils, and air coolers, respectively. The model is validated with theoretical and experimental data across three tiers (frozen layer, floor, and room levels), and the root-mean-square error of frozen surface temperatures remains within 0.3 °C. A simplified indoor ice rink case study demonstrates the integrated model’s capability: hourly simulation results of temperatures and thermal loads exhibit reasonable seasonal and diurnal variations, aiding in analyzing floor insulation thickness and determining when floor heating coils are required. This work can provide a fundamental simulation analysis tool for the energy-efficient design and operation of indoor ice rinks and ski resorts.</p>