# Estimation of Thermal Radiation in Bed Mattresses
## 6 Conclusions  
In this study, we confirmed thermal radiation measurements through a real-scale model experiment on mattresses at different installation heights and compared the experimental and predicted calculation results. The results are as follows:  
1. When a fire occurs, if there is space under the mattress, the HRR, flame height, and thermal radiation may increase due to the fallen material accompanying the flame. Therefore, the results of this experiment based on different mattress installation heights provide information on the fire risk of mattresses.
2. When calculating the thermal radiation of solid combustibles, when the HRR is high and the flame forms rapidly, an international standard for estimating the thermal radiation of a calculation method that applies different configuration factors according to changes in flame shape is also necessary.
3. Although there are several techniques for estimating the thermal radiation risk, to apply them in practice, the type of combustible, the mass loss rate, the effective heat of combustion, the heat release rate, the combustion area, and the configuration factor must be suitably calculated.
4. In the direction of the heat flux meter, as in the analysis result of this study, when designing an experiment for fire risk evaluation, it is considered to be an appropriate method for fire risk assessment to design the direction of the heat flux meter to face the flame.  
This study examined the thermal radiation estimation methods for fires in an open space. The prediction of heat radiation for solid combustibles enables the estimation of the extent of flame spread, and the loss of heat radiation can lead to the extinction of flames. Therefore, it is absolutely necessary to establish an international standard for solid combustibles, as shown in the results of this study. Furthermore, as humans live in one space, if a fire occurs within a compartment, the risk is expected to increase due to thermal radiation from the smoke layer, the reflected emissivity from walls, and convective heat, in addition to direct radiation from the flames. As such, further research on estimating thermal radiation within a compartment is necessary.  
Conceptualization, K.-W.P., M.M., C.-G.C. and J.-J.J.; Data curation, K.-W.P. and J.-J.J.; Formal analysis, K.-W.P., M.M. and C.-G.C.; Funding acquisition, K.-W.P.; Investigation, J.-J.J.; Methodology, K.-W.P., M.M., C.-G.C. and J.-J.J.; Project administration, M.M.; Resources, J.-J.J.; Software, J.-J.J.; Supervision, C.-G.C.; Validation, K.-W.P. and M.M.; Visualization, J.-J.J.; Writing--original draft, K.-W.P.; Writing--review & editing, C.-G.C. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Research Foundation of Korea (NRF), grant number 2021R1A6A3A01086444, and by the Korea Institute for Advancement of Technology (KIAT) of Industrial Technology of the Ministry of trade, industry, and energy, Republic of Korea, grant number P162500261.  
Not applicable.  
We would like to express our gratitude to [PERSON], Department of Architecture, Faculty of Science and Technology, Tokyo University of Science, for participating in this experiment and providing advice.  
The authors declare no conflict of interest.