A new Chinese Kang with forced convection: System design and thermal performance measurements

The Chinese Kang, a traditional heating device, is widely used in northern rural China. It recovers the heat from cooking smoke and provides local thermal comfort to people sitting or lying on it. However the heat supply ability of the traditional Kang is limited due to constraints of the surface temperatures and heat transfer coefficients. In this paper, a new Chinese Kang with forced convection (CKFC), which adopted hot water as the heat transfer medium and added a small fan to enhance convective heat transfer, was developed. A full-scale CKFC system was constructed for actual application in a rural house and its thermal performance was measured. Experimental data show that during the space heating period, the heating power of forced air convection ranged from 625 W to 1170 W, while that through the CKFC surfaces was only 200-500 W in the local heating or space heating mode to maintain local thermal comfort. Meanwhile, the CKFC retained the merits of a traditional Kang by providing local thermal comfort. The measured asymmetry of Kang plate surface temperatures was 6.7 °C. Overall, the CKFC has satisfactory performances as a new heating terminal device in rural houses.