A Feasibility Study on the Insulation Reinforcement Effect of the North-Facing Apartment Wall

Korean apartment buildings are traditionally designed with a strong preference for south-facing orientations and balcony extensions are common.The south-facing faades of the dwelling units benefit from solar heat gains during winter owing to the low solar altitude at noon, resulting in relatively low heating loads.In contrast, north-facing faades do not receive direct solar radiation, which inevitably leads to greater heat losses compared with other orientations.Therefore, examining the thermal characteristics of north-facing rooms and quantitatively identifying the effects of the insulation reinforcement of north-facing walls are important for establishing energy-saving strategies for new construction and renovation projects.Accordingly, this study focused on a typical flat-type apartment unit, and the thermal environment and heat transfer during the heating period in rooms facing north were extensively investigated.Additionally, the heating energy-saving effects resulting from the insulation reinforcement of the north-facing walls were evaluated.Consequently, the north-facing room was scarcely influenced by direct solar radiation, and its average indoor temperature in winter under non-heating conditions was approximately 5 lower than that of the south-facing room.Although the south-facing room experienced almost no heating load, even during winter, the north-facing room exhibited heating loads of approximately 3-6 kWh/m 2 in January-February and December.Insulation reinforcement of north-facing walls reduced the heating load by approximately 7.2-7.9%for the entire dwelling unit, whereas a reduction of 15.8-17.2%was observed when the analysis was limited to a north-facing room.Based on these results, the insulation reinforcement of north-facing walls is expected to be highly effective in reducing the heating energy consumption.