## 2 Experimental Setup
### Measurements' Instrumentation  
Many measuring devices were positioned inside and around the compartment to capture as many changes as possible to the fire dynamics, flow field through the openings, external plume size, and external radiation due to the effect of the location and size of the horizontal opening. The HRR was measured using the oxygen consumption method, and the calculations were based on the method proposed by [PERSON] [32] with an estimated error of \(\pm\)10% for complete combustion conditions. This error increases in the case of incomplete combustion and/or sooty exhaust gases and carbon monoxide. As presented in Figures 8 and 9, four thermocouple (TC) trees were placed at each corner of the compartment at 50 mm away from each wall. The TCs were of 1.5 mm Type K (estimated negligible measurement error), with five TCs at each corner distanced 100 mm from each other, the roof, and the floor. Thin Skin Calorimeters (TSCs) were used to capture the incident radiative heat flux at different locations around the compartment. The TSCs were in-house designed according to the description, calibration, and estimated uncertainties are presented in details in [33]. In short, the main uncertainties are associated with the assumption of uniform temperatures in the compartment and uniform heat flux distribution onto the solid elements, the radiative effect on the thermocouple bed, and the complexity of estimating the heat transfer coefficient (e.g., convective term). A total of 13 TSCs were mounted at distances of 300, 450, and 650 mm from the top of the door: one TSC at 150 mm from the top center of the back wall, three TSCs at 150, 300, and 450 mm from the top middle side of the left wall. To ensure correct measurements via the TSCs, two water-cooled heat flux gauges were placed at 600 mm from the top of the door, and another was placed at 150 mm from the middle of the side wall. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Total Horizontal** **(m\({}^{2}\))**}} & \multicolumn{1}{c}{**Equivalent Four-Corner Openings**} & \multicolumn{1}{c}{**Equivalent Central**} & \multirow{2}{*}{**Percentage of the Total Roor Area** **[**\%**]**} & \multirow{2}{*}{**Repeated** **[**Number of Times**]**} \\
**Total Horizontal** & **(m\({}^{2}\))** & **(m\({}^{2}\))** & & & \\
**Openings Area** & **[Case Naming]** & **(m\({}^{2}\))** & & & \\
**(m\({}^{2}\))** & **C: Corner** & **[case Naming]** & & & \\
**CL: Closed** & **S: Slot** & & & \\ \hline
0.0 & [CL] & & & Yes \\
0.0025 &
\begin{tabular}{c} (0.025 \(\times\) 0.025) \(\times\) 4 \\ [C\({}_{-}\)0.0025] \\ \end{tabular} & - & 0.4\% & NO \\ \hline
0.01 & \
\begin{tabular}{c} (0.05 \(\times\) 0.05) \(\times\) 4 \\ [C\({}_{-}\)0.01] \\ \end{tabular} &
\begin{tabular}{c} 0.6 \(\times\) 0.02 \\ [S\({}_{-}\)0.01] \\ \end{tabular} & 2\% & NO \\ \hline
0.04 & \
\begin{tabular}{c} (0.1 \(\times\) 0.1) \(\times\) 4 \\ [C\({}_{-}\)0.04] \\ \end{tabular} &
\begin{tabular}{c} 0.6 \(\times\) 0.07 \\ [S\({}_{-}\)0.04] \\ \end{tabular} & 7.4\% & NO \\ \hline
0.09 & \
\begin{tabular}{c} (0.15 \(\times\) 0.15) \(\times\) 4 \\ [C\({}_{-}\)0.09] \\ \end{tabular} &
\begin{tabular}{c} 0.6 \(\times\) 0.15 \\ [S\({}_{-}\)0.09] \\ \end{tabular} & 16\% & NO \\ \hline
0.16 & \begin{tabular}{c} (0.2 \(\times\) 0.2) \(\times\) 4 \\ [C\({}_{-}\)0.16] \\ \end{tabular} & \
\begin{tabular}{c} 0.6 \(\times\) 0.27 \\ [S\({}_{-}\)0.16] \\ \end{tabular} & 29.6\% &
\begin{tabular}{c} Yes \\ [1\({}^{*}\) S\({}_{-}\)Poly] \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Experimental cases. Figure 8: Instrumentations’ locations plan view (note: not to scale).