# Thermal Energy Storage for Building Load Management: Application to Electrically Heated Floor
## 3 Results
### Parametric Study
#### 3.1.3 Concrete on the Top  
Further simulations were performed to investigate the impact of the thickness of the upper (screed) layer of concrete on the thermal behavior of the building. Table 6 shows that as the concrete thickness on the top increases, the maximal operative temperature and the FST-at-8:00 p.m. increase. Moreover, the maximal FST, the maximal operative temperature and the drop of the operative temperature above 20 \({}^{\circ}\)C appears significantly later. In fact, with the increase of the concrete thickness, a higher amount of energy is stored and released. Finally, the increase of the concrete thickness increases the energy consumption until provide enough energy to have an acceptable TC (operative temperature higher than 20 \({}^{\circ}\)C until the end of the peak period from 6 cm of concrete). In summary, the screed layer thickness has an important effect on the EHF performance. It allows more energy to be stored thus provides a longer period of acceptable TC for the occupants.  
To compare the two concrete layers, the case with 4 cm of concrete on the bottom (and 10 cm on the top) and the case with 12 cm of concrete on the top (and 2 cm of concrete on the bottom) are  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{\
\begin{tabular}{c} **Thickness of** \\ **concrete on the** \\ **top (m)** \\ **(\({}^{\circ}\)C)** \\ \end{tabular} } & \multicolumn{3}{c}{**FST**} & \multicolumn{3}{c}{**Operative Temperature**} & \multirow{2}{*}{
\begin{tabular}{c} \(E\) \\ **(kWh/Day)** \\ \end{tabular} } \\ \cline{2-2} \cline{4-7}  & **Max** & **Daytime** & **\(T_{\text{floor\_surf}}\)** & **at 8:00** & **Max \(T_{\text{op}}\)** & **Daytime** & **Daytime** \\  & **(\({}^{\circ}\)C)** & **max (\(h:m\))** & **pm (\({}^{\circ}\)C)** & **(\({}^{\circ}\)C)** & **(\(h:m\))** & **(\(h:m\))** & **(\(h:m\))** \\ \hline
0.02 & 28.46 & 4:12 am & 19.02 & 22.46 & 7:56 am & 3:52 pm & 90.54 \\
0.04 & 28.21 & 4:37 am & 20.82 & 22.67 & 8:54 am & 6:28 pm & 93.41 \\
0.06 & 28.12 & 4:44 am & 22.09 & 22.85 & 9:33 am & 8:29 pm & 95.49 \\
0.08 & 28.13 & 5:31 am & 23.05 & 23.02 & 10:13 am & 10:01 pm & 97.18 \\ \hline
0.10 & 28.16 & 6:19 am & 23.85 & 23.22 & 10:39 am & 10:50 pm & 98.71 \\ Reference Case & 28.16 & 7:04 am & 24.58 & 23.43 & 11:25 am & 11:21 pm & 100.15 \\
0.14 & 28.26 & 7:50 am & 25.20 & 23.61 & 11:48 am & 11:37 pm & 101.79 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Results of the parametric study: Impact of the top layer concrete thickness.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{\
\begin{tabular}{c} **Thickness of** \\ **Concte on the** \\ **Bottom (m)** \\ **(\({}^{\circ}\)C)** \\ \end{tabular} } & \multicolumn{3}{c}{**FST**} & \multicolumn{3}{c}{**Operative Temperature**} & \multirow{2}{*}{
\begin{tabular}{c} \(E\) \\ **(kWh/Day)** \\ \end{tabular} } \\ \cline{2-2} \cline{4-7}  & **Max** & **Daytime** & **\(T_{\text{floor\_surf}}\)** & **at 8:00** & **Max \(T_{\text{op}}\)** & **Daytime** & **Daytime** \\  & **(\({}^{\circ}\)C)** & **Max (\(h:m\))** & **pm (\({}^{\circ}\)C)** & **(\({}^{\circ}\)C)** & **(\(h:m\))** & **(\(h:m\))** & **(\(h:m\))** \\ \hline
0.02 & 28.16 & 6:19 am & 23.85 & 23.22 & 10:39 am & 150 pm & 98.71 \\ Reference Case & 28.16 & 7:57 am & 25.34 & 23.65 & 11:59 am & 11:41 pm & 101.17 \\
0.08 & 28.15 & 8:26 am & 25.70 & 23.71 & 12:11 am & 11:46 pm & 101.79 \\
0.10 & 28.04 & 8:29 am & 25.88 & 23.69 & 12:13 am & 11:47 pm & 102.08 \\
0.12 & 27.95 & 8:25 am & 25.98 & 23.66 & 11:52 am & 11:48 pm & 102.04 \\
0.14 & 27.89 & 8:19 am & 26.04 & 23.64 & 11:43 am & 11:49 pm & 102.01 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Results of the parametric study: Impact of the lower layer concrete thickness.  
compared. The results are really close. Thus, the concrete thickness has a significant impact on the performance, not the position of the concrete regarding the EHF.