https://doi.org/10.6110/KJACR.2024.36.10.481

Ho Jeong Woo ; Do Jin Lee ; Ji Ho Park ; Sangmu Bae ; You-Sik Lee,Y ujin Nam ;

Recently, officetel building fires are continuously occuring as the number of single-person households is increased. Since officetel buildings are designed with a focus on economics and sales, it is difficult to evacuate for occupants during fire events. Therefore, architectural plans are needed for evacuation of occupants in officetel buildings. This study aimed to propose improvement methods for horizontal evacuation in officetel buildings based on analysis results of domestic and international egress codes. Fire risk and horizontal evacuation performance were quantitatively evaluated using simulation models by comprehensively considering building materials, rooms, occupants, and fire characteristics of officetel. Architectural plans included width of corridor, width of exit door, and arrangement of exit based on building and egress regulations. Available safe egress time (ASET) was increased when corridor and exit door were wider and required safe egress time (RSET) was decreased due to elimination of bottlenecks. However, to ensure safe evacuation performance for occupants, widths of corridor and exit door need to be improved beyond building regulations. The central spaced arrangement was appropriate for center core type officetel buildings. The central spaced arrangement had a constant distance from all rooms, causing fewer bottlenecks than other arrangements.

https://doi.org/10.6110/KJACR.2024.36.10.490

Seungmin Jang ; Jinkyun Cho ; Wonseok Oh ; Jeongan Park ; Cheolwoong Shin ; Jinho Kim

This study investigated the integration of HEPA filters with air conditioning systems to improve indoor air quality, focusing on fine particulate matters (PM10 and PM2.5) recognized as carcinogens by the WHO. In South Korea, particulate matter levels increase from winter to spring due to domestic emissions and cross-border pollution. HEPA filters were attached to existing air conditioners. Their particulate removal efficiency and clean air delivery rate (CADR) were measured in a control chamber. Preliminary tests showed a 22% reduction in airflow with filters installed. Filters achieved a high efficiency of 93%. In a low airflow mode, the air conditioner with a HEPA filter achieved a CADR of 1.44 m³/min and a particulate removal efficiency of 61%. In a high airflow mode, the air conditioner with a HEPA filter achieved a CADR of 1.83 m³/min and a particulate removal efficiency of 70%. These results suggest that integrating HEPA filters with air conditioning systems can significantly enhance air purification, especially in high-occupancy areas such as classrooms, offices, and lecture halls. This approach not only optimizes the use of existing air conditioning infrastructure, but also offers a practical solution for improving indoor air quality during periods of high particulate matter levels. Future research needs to focus on large-scale implementation and effects on cooling efficiency and noise levels.

https://doi.org/10.6110/KJACR.2024.36.10.500

Jaedeok Ko ; Seongjun Jeon ; Ji Hwan Jeong

This study experimentally investigated the influence of a suction pipe material of a non-adiabatic capillary tube commonly employed as an expansion device in a majority of household refrigerator-freezers on refrigeration system performance. An experimental refrigeration system was constructed utilizing system components from an actual domestic refrigerator using R-600a as a refrigerant. Two non-adiabatic capillary tubes that were identical in shape and joint method but with different suction pipe materials (copper vs. aluminum) were employed as test samples. These capillary tubes were alternately installed and subjected to identical operating conditions for testing. Upon utilization of both non-adiabatic capillary tubes, performance indicators such as refrigerant mass flow rate, cooling capacity, and coefficient of performance showed no significant disparities. Consequently, this study demonstrates that using either capillary tube to an actual household refrigerator-freezer would not result in any substantial differences in the appliance’s power consumption.

https://doi.org/10.6110/KJACR.2024.36.10.507

Yu Jun Jung ; Hak Su Kim ; Hee Young Kim ; Jin Doo Kim ; Dong Ho Kmi

This study aimed to analyze energy balance of a paper drying process to apply a high-temperature heat pump. Energy consumption for the paper drying process was analyzed in two ways based on paper production data and hood air balance. Paper production data, including product production speed, size, basis weight, and moisture content, were used to analyze moisture evaporation amount and its corresponding energy consumption for drying. In addition, the drying energy consumption used in the paper drying process was analyzed based on data of flow rate, temperature, and humidity of the hood's exhaust/supply air. As a result, the energy consumption calculated by the two methods showed similar values. Based on this result, the amount of steam corresponding to each location in the paper drying process was calculated. Based on the amount of steam, it is expected that process locations that can be replaced by industrial heat pumps can be identified in the future.

https://doi.org/10.6110/KJACR.2024.36.10.513

Seajoong Kim ; Sumin Kim

A Study on Pollutant Emission Patterns from Composite Finishing Materials and Indoor Air Quality Improvement through Flush-Out