Tiannuan is the abbreviation of a ceiling far-infrared radiation heating system. Far-infrared flat radiant heating system was produced in the United States in 2000. Because the system is installed on the ceiling, it is called "warm weather" in China. At present, the manufacturers are all over Qingdao, Weihai, Harbin, Shanghai, Foshan and Chengdu. China is dominated by nano-scale "global warming" with negative ions, which has entered thousands of households in the south of the Yangtze River. Different from traditional heating methods, sky heating does not use air as a medium, but directly heats objects by far infrared. Sky heating is the most advanced heating system at present, which overcomes the defects of traditional heating and integrates environmental protection, comfort, health and intelligence.