## 3 Results
### UHI Indirect Impact Evaluation  
#### 3.2.1 Cooling Demands Estimation Studies--Energy Use Intensity (EUI) Indicator  
The cases examined are summarized in Figure 20 and relate to a great extent to the ventilation strategy and the material properties. More specifically, Case#1 assumed a small inlet and outlet opening, whereas the rest of the parameters remained unaltered with the default property of an ETFE textile with no additional treatment or coating. For comparison on the air inflow impact, Case#2 considered a larger operable effective area, to evaluate whether the air inflow resulted in a reduction of the cooling loads or led to overheating of the cavity, while in Case#3, the cavity was assigned as only slightly ventilated with minimized vents open (in reality, a fully sealed cavity cannot be achieved with the current design). Figure 19: Comparative sun ray trace analyses of the proposed facade (left) and a typical facade in an urban street canyon, including the reflection towards the opposite building. Figure 20: Overview of the case studies and test parameters for the EUI calculation studies for the cooling loads. From Case#4 on, the SHGC of the translucent textile had a lowered value, and in Case#5, a smaller cavity size was tested. Case#6 explored the ventilation scenario for an only night-time ventilation to aid the exhaust of the accumulated heat that is trapped inside the cavity during the day, with a scheduled air exchange between the thermal zones. In Case#7, no natural ventilation was enabled through the cavity, with no direct air exchange between the thermal zones, but allowing only heat exchange through the construction and some air flow through the cavity to the top exhaust. Lastly, the Case#8 scenario explored the possibility to avoid the double skin function during the summer, eliminating the cavity effect and not allowing any natural ventilation or air exchange to the interior. In this case, the facade skin works only as an independent exterior shading device, without creating any in-between thermal zone. As for the existing single facade case study, to avoid complications with natural ventilation strategies, which was an unknown variable in this case, and to make comparison as objective as possible, the air loads system was assumed to be conditioned and mostly functioning through mechanical ventilation, while the glazing type was assigned as a generic double-pane window without low-e coatings. Additionally, in the cases where natural ventilation was enabled, it was set to be activated with a delta temperature setpoint at \(-2\)\({}^{\circ}\)C in relation to the cooling setpoint. A summary of the results for the cooling loads per area can be found in Figure 21, whereas the difference in percentage compared to the existing single facade was also calculated. The energy balance (in kWh) and the floor-normalized cooling load for the building (in kWh/m\({}^{2}\)) charts for the analyzed period are shown below for each corresponding case (Figure 22). Figure 21: Results of the EUI calculations for the cooling loads of the case studies shown in Figure 20.  
Figure 22: Cont. From the above studies, it can be concluded that during the cooling-dominated periods, the air inflow inside the cavity led to an overheating of the building due to the greenhouse effect inside of it. A higher amount of air inflow resulted, therefore, in an increase in the cavity temperature, as can be seen in Cases#1 and #2 with an increase of 21% and 21%. Figure 22: Energy balance charts (**left**) and EUI of the cooling loads charts (**right**) for each case study shown in Figure 20.  
57% of the cooling demands, respectively. The increase was also caused by the absence of additional solar control coatings on the textile surface, which is one of the variables that influenced the cooling demands value, as can be seen in Case#4, with a reduction of \(-13\%\), as a result of the reduction of the SHGC coefficient value.