Experimental study on internal heat transfer among adjacent rooms for building energy efficiency with housing vacancy consideration

With the expansion of the real estate sector and the rise of tourist resorts, many individuals now own multiple properties, resulting in a substantial number of homes remaining vacant for extended periods or being used seasonally. Despite being unheated, rooms in these vacant properties continue to transfer heat to adjacent heated rooms. While previous research has explored the heat transfer between non-heated and heated rooms based on their relative positioning, few studies have considered the dynamic aspects of this process. To fill this gap, we developed a scaled-down model to replicate real-world conditions and conducted experiments to track the dynamic temperature changes between non-heated and heated rooms in different configurations. The heat transfer mechanism was analyzed, and a theoretical model was constructed to quantify the dynamic heat exchange. This model accounts for variations in both convective and radiative heat transfer between rooms. Initial findings suggest that heat transfer to a non-heated room below a heated space can reach 28 % of the total heat supplied, while heat transfer to an upper adjacent room can account for 16 %. The peak heat transfer is observed after 5–10 h of heating. These results provide valuable insights for optimizing space heating, promoting energy-saving practices, and improving indoor heating efficiency, alongside offering actionable recommendations for behavioral energy conservation.