Because of the need to circulate heat, the end of this path has a smoke pipe design. This heating line also goes straight to the king’s bed and other people’s beds, creating “warm beds” and “warm rooms”, making the palace feel as warm as the season. Spring. In winter, during the royal palace of Minh Thanh Dynasty, most of them burned charcoal to keep warm. Therefore, there is also a structure in charge of burning coal “keeping warm” in the winter, with the function of Tan Ti, specialized in the supply of charcoal in the palace.