This study presents results of Computational fluid dynamics (CFD) analysis conducted to evaluate performances of various functional products developed for smart bathroom systems. The primary objective was to analyze the efficiency of space heating, direct drying, and dehumidification functions in a winter bathroom environment. Representative bathroom models in South Korea were selected and detailed CFD simulations were performed on these models. Results showed that bathtub models exhibited higher efficiency overall in space heating and dehumidification than shower booth models. This was attributed to differences in bathroom structure and internal air flow. Additionally, the direct drying function showed higher efficiency in bathtub models, determined by the placement of air outlets and inlets. This study provides essential foundational data that can contribute to the design and enhancement of smart bathroom systems' functionality, offering valuable insights for the development of optimized smart bathroom products.