As an energy-efficient and comfortable heating method, radiant floor heating systems have been extensively studied for household and zonal control, with CFD simulation being a widely used approach. However, most existing CFD models adopt fixed wall temperatures or constant heat flux densities, which fail to accurately reflect the effects of water-side regulation and non-heated surfaces on radiant heat transfer. In this study we proposed a novel boundary heat transfer model for radiant floor heating that incorporates supply water temperature, flow rate, and non-heated surfaces into floor heat transfer calculations. Based on data from the JGJ142 standard, the model derives fitted values for upward and downward heat flux. A comparison was made between two flow distribution strategies: zonal control (Scenario 1) and uniform distribution (Scenario 2). Thermal comfort was shown to be maintained with a 15–20% reduction in flow demand achieved through selective 50% flow reduction in non-critical zones, when compared to uniform distribution. The proposed zonal control strategy achieves faster heating rates and improved temperature stability in bedrooms, despite exhibiting slight thermal lag in common areas, thus providing an effective solution for energy-efficient personalized thermal comfort.