## 5 Result Analysis
### Case 4  
In Case 4, the nominal thermal load in the heat flow frontier condition, as mentioned in Section 4, and provided by the data center room, is \(q_{adm}=0.340\). As in previous cases, the maximum and minimum air flow velocity were applied. The scale was changed for Case 4 and it does not present the maximum value existing in the other three cases. The reason is that this case study has lower temperatures and small differences would not be perceptible. By focusing on a narrower scale, it is possible to differentiate between slight changes in temperature.  
The result of simulations for the minimum level of air flow velocity and the obtained temperature field predictions can be seen, respectively, in Figures 17 and 18 for the \(y\) and \(z\) planes.  
Figure 16: The results of the field of temperature in the \(x\)–\(y\) plane through the: (**a**) \(z_{adm}=0\); (**b**) \(z_{adm}=0.244\); (**c**) \(z_{adm}=0.489\); and (**d**) \(z_{adm}=1\).  
Figure 17: The results of the field of temperature in the \(x\)–\(z\) plane through the planes: (**a**) \(y_{adm}=0.100\); (**b**) \(y_{adm}=0.485\); and (**c**) \(y_{adm}=0.900\).  
In the planes shown in Figure 17, it can be observed that the greater development of hot spots occurs at the terminations of the rows of the server racks. The temperature fields of the \(x\)-\(y\) planes (Figure 18) represent the temperature prediction for a usual thermal load with minimum air flow velocity. Due to the normal operation of the server racks, the air flow velocity is insufficient to avoid the formation of hot spots in several server racks. In the extraction zone, hot spots are not expected since the average dimensionless temperature does not exceed \(T_{adm}=0.125\).  
Figure 19: The results of the field of temperature in the \(x\)–\(z\) plane through the planes: (**a**) \(y_{adm}=0.100\); (**b**) \(y_{adm}=0.485\); and (**c**) \(y_{adm}=0.900\).  
Figure 18: The results of the field of temperature in the \(x\)–\(y\) plane through the planes: (**a**) \(z_{adm}=0\); (**b**) \(z_{adm}=0.244\); (**c**) \(z_{adm}=0.489\); and (**d**) \(z_{adm}=1\).  
By analyzing both Figures 17 and 18, it can be assessed that the server racks at the end of the rows reach higher temperatures, meeting the dimensionless temperature value of \(T_{adm}=0.400\). The hot aisles are expected to reach the maximum average mean temperatures, \(T_{adm}=0.120\).  
The result of simulations for the maximum level of air flow velocity and the obtained temperature field predictions can be seen, respectively, in Figures 19 and 20 for the \(y\) and \(z\) planes.  
By observing Figure 19, it is possible to assess that the values obtained in the dimensionless temperature range of the server racks do not exceed the value, \(T_{adm}=0.160\). In the extraction zone, the simulations show that hot spots are not foreseen to occur, since the value of the dimensionless temperature field does not exceed the value of \(T_{adm}=0.06\).  
Figure 20 shows the absence of hot spots, since the inlet air flow velocity proves to be oversized for this case study, which naturally leads to the prediction of low values in the extraction zone. It can be seen that server racks at the end of the rows are very close to the values of the central server racks, since the scale does not present the maximum value existing in the other three cases. Thus, it can be seen that there are no hot spots in any server rack. The value of the temperature range in the extraction zone is almost identical to that of the inlet air temperature.