The objective of this study is to establish boundary conditions to evaluate the cooling capacity of the Cooling Radiant Ceiling Panel (CRCP) considering the environment of a room equipped with the CRCP. The current study investigated the boundary conditions and derivation techniques from previous studies. Based on the results of the analysis, a heat transfer model was derived for a room fitted with CRCP. In addition, the heat transfer model was used to derive the factors affecting the cooling capacity of the CRCP and each factor was simulated and verified through this model. The effects of these factors on the capacity of the CRCP was established by using various boundary conditions. To verify the validity of the simulation model, the experimental results were compared with the cooling capacity for a specific case. As a result, it was established that even for the same panel, there was a variance in the cooling capacity of the CRCP based on the boundary conditions and that the influence of the surface exposed to the outdoors had more implications. Consequently, this study presents the influence factors to be considered when designing CRCP.

In this paper, a novel combined radiation-convection floor heating system is shown. This study uses practice-based learning and investigated the thermal performance of a combined radiation-convection floor heating system with a water heat pump system by evaluating the thermal environment and energy consumption in an experimental test. A new method that analyzed the thermal performance of four different controls was developed and applied. The results of the surface temperature distributions demonstrated that Mode 1, which uses only convection, had the lowest floor temperature and was thus considered inappropriate for occupants who sleep on the floor. By contrast, Modes 2, 3, and 4 showed high floor surface temperatures as hot water was supplied to the radiant heating panel. The predicted mean vote (PMV) results suggest that radiant floor heating is not appropriate for intermittent heating. In other words, occupants of single residences who return home at night will experience a long period of discomfort if they heat their room using floor heating. In this case, Mode 1, which is convection heating, and Modes 3 and 4, which represent mixed modes provide a more comfortable environment. The difference between this experimental study and previous research is that four different control modes for a combined radiation-convection system were evaluated based on the same location of the equipment in a laboratory. Furthermore, we studied the long-term real-scale thermal performance using panel and energy consumption.

As small obsolete buildings are exposed to high fire risks, governments are trying to evaluate their fire risks and preferentially improve fire protection performance for high risk buildings, however, the evaluation manpower and time are insufficient compared to the rapidly increasing number of obsolete buildings. Therefore, this study aimed to derive major fire risk index (FRI) evaluation items as part of developing a platform to quickly and efficiently evaluate fire risks in dense areas of small obsolete buildings utilizing spatial information convergence technology. To this end, 20 preliminary evaluation items specifically tailored to dense areas of small obsolete buildings were derived through a field survey, investigation of FRI evaluation items from existing works, and expert pre-reviews. Based on the derived 20 preliminary items, an importance survey was conducted with a total of 181 fire safety experts including fire officers, university professors, researchers, industry experts, and fire insurers. As a result, a total of 12 major evaluation items (e.g., outdoor fire extinguisher, distance to 119 Safety Center, building structure, building cladding, illegal alterations, illegal parking, and liquefied natural gas cylinder) were derived. Results can help to evaluate the fast and efficient fire risks in dense areas of small obsolete buildings.

Given the increasing severity of climate change, we propose a small-scale carbon capture, utilization, and storage (CCUS) system applicable to domestic household boilers. The device is designed to be easily attached to existing boiler piping without requiring structural modifications. We conducted experiments using a custom-made acrylic chamber to evaluate the performance of the proposed system in capturing carbon dioxide. The solution with the highest CO₂capture performance was selected through comparative experiments with various absorbent solutions. The results suggest that the proposed CCUS device can reduce direct emissions from residential buildings. This study provides a practical solution to reduce carbon emissions from households and facilitate carbon reuse.

This study investigated the impact of the plenum load on the cooling capacity of ceiling radiant cooling panel (CRCP) systems. A two-dimensional simulation model using Physibel BISCO was developed to represent a small room (3.8 m (L) × 2.9 m (H)) equipped with CRCPs. To analyze the plenum load impact depending on the CRCP type (top insulation, and open-or closed-type installation), three cases were considered: closed-type with top insulation (Case 1), closed-type without top insulation (Case 2), and open-type without top insulation (Case 3). The simulation results showed that the presence of the plenum load increased the plenum air temperature and caused the CRCP to absorb part of the plenum load, consequently leading to the enhanced cooling capacity of the CRCPs. When the plenum load increased to 10%-20% of the room load, the cooling capacity was enhanced by 7.9% ~ 16.8%, compared to the case without a plenum load. This implied that CRCPs could be undersized when they are designed without considering the plenum load. Furthermore, the cooling capacity showed a greater enhancement in the CRCPs without top insulation (Cases 2 and 3) than in those with top insulation (Case 1). Particularly, a higher cooling capacity was obtained with a higher water temperature when applying CRCPs without top insulation. The results suggested that open-type CRCPs without top insulation would be a good cooling solution for a room with a plenum because they are suitable for removing the plenum load even at relatively high water temperatures.