Main principle of the thermally active building system (TABS) which is a type of radiant heating system operating at low temperatures range as 30–50 ˚C is to bring the ambient temperature to the desired level by heating the building mass. TABS system is also a system that can heat at low temperatures such as underfloor heating systems, and both systems can be applied in multi-story buildings. Because these systems operate at low temperatures, they are compatible with both each other and with renewable energy sources. At the same time, heating and cooling at temperatures close to room temperature can also increase the coefficient of performance (COP) in these systems. In this study, a double-layered system which is a new concept was designed by using both underfloor heating and TABS on the same floor; and the thermal performance of the double-layered TABS system (DLTS) was examined using the FLUENT/ANSYS programs. In the calculations, different supply water temperatures (30, 35 and 40 °C) and the pipe positions on the vertical axis (0.001 m, 0.050 m, and 0.100 m) were considered. It can be obtained from the results that the efficiency of the heating systems can be increased by using the new DLTS proposed in this study.

热活性建筑系统（TABS）的主要原理是一种在30至50°C的低温范围内运行的辐射供暖系统，其作用是通过加热建筑质量使环境温度达到所需水平。TABS系统也是可以在低温下加热的系统，例如地板采暖系统，并且两种系统都可以应用于多层建筑物中。由于这些系统在低温下运行，因此它们彼此兼容并且与可再生能源兼容。同时，在接近室温的温度下加热和冷却也会增加这些系统的性能系数（COP）。在这项研究中，通过在同一层上同时使用地板采暖和TABS设计了双层系统，这是一个新概念。并使用FLUENT / ANSYS程序检查了双层TABS系统（DLTS）的热性能。在计算中，考虑了不同的供水温度（30、35和40°C）和垂直轴上的管道位置（0.001 m，0.050 m和0.100 m）。从结果可以看出，通过使用本研究中提出的新的DLTS，可以提高加热系统的效率。