## 5 Calculating the MUA's Energy Demand
### Incorporation of Thermal Solar Panels to the TCP Panel Installation  
The energy savings gained by incorporating a system of thermal solar panels on the rooftop into the installation of air conditioning based on radiant floor TCP panels (OP3) will be analysed [39]. These solar thermal panels operate by heating the system's water in winter or cooling it in summer by means of an absorption cooling system [40; 41], or chemical energy (solar cold) [42; 43]. The solar radiation power data on the MUA's rooftop were collected during the complete year 2015 cycle, by  
Figure 11: CFD graphic of the applied radiant floor system based on TCP panels. Cross section of the MUA. Indoor air temperatures. 1 February 2015. 9:00 a.m. \begin{table}
\begin{tabular}{l c c c} \hline  & **OP1** & **OP2** & **OP3** \\ \hline Energy demand in summer kWh/m\({}^{2}\) & 89.79 & 67.43 & 35.91 \\ Energy demand in winter kWh/m\({}^{2}\) & 41.04 & 30.82 & 15.39 \\ Annual energy demand kWh/m\({}^{2}\)y & 130.83 & 98.25 & 51.30 \\ Annual CO\({}_{2}\) emissions in use stage & 50,071.91 & 37,603.22 & 19,633.17 \\
**Percentage** & **100.00\%** & **75.09\%** & **39.21\%** \\ \hline \end{tabular}
\end{table} 
Table 3: Calculation of energy demands and CO\({}_{2}\) emissions of the 3 OP. Figure 10: Computational fluid dynamics (CFD) graphic of the existent all-air system. Cross section of the MUA. Indoor air temperatures. 1 February 2015. 9:00 a.m.  
means of the pyranometer installed on the wireless monitoring system described above. Scheme 2 shows the radiation values obtained for the months of August and February. Table 4 shows the daily average values of energy collected each month, as well as total days of sunshine. These values were compared with other sources and recent publications that collected these values for the Spanish Levante; correlated values were obtained [42; 44]. The installation dimensioning was performed according to the load calculations using Design Builder (Table 2), after calibrating the model using the surface temperatures and indoor air temperature monitoring results. An installation of 230 m\({}^{2}\) of thermal solar panels is required for a yearly air conditioning energy demand of 98.25 kW/m\({}^{2}\)y with an installation of two 150 kW power heat pumps in cold mode in summer. Based on the usual performance of these facilities based on the sun, these panels contributed 62.2% to the system during energy demand peaks in summer in the case of maximum sunshine [20]. The installation performance of 230 m\({}^{2}\) of solar thermal panels, with a 38\({}^{\circ}\) latitude and a 45\({}^{\circ}\) inclination, was 71.4% [45]. Taking into account that overall installation performance was 84.5% [46], total energy contribution to the TCP panel radiant floor system, using water in winter, and a solar cooling system with energy storage by lithium chloride (LiCI) was 66,559 kWh/y. The results obtained by the Design Builder simulation were calibrated and corrected using these on-site solar energy results [13] and compared to other studies on thermal energy in similar climates [42; 47; 48]. The system's energy savings were of 60.79% compared to all-air convective systems