# Experimental Investigation and Optimization of a Glazed Transpired Solar Collector
## 2 Materials and Methods
### Integration of the Optimized GTC into a Building Facade  
#### 2.2.1 Experimental Set-Up and Protocol  
This second experimental study is performed by means of a full-scale experimental building, using a light container-type structure (6 m \(\times\) 2.4 m \(\times\) 2.5 m). The optimized GTC (with a distance between the perforated plate and the glass of 30 mm), according to the results presented above, is mounted on the facade of the container (Figure 6).  
Figure 5: GTC global efficiency.  
This experimental set-up was also located near the CAMBI Research Center, within the premises of the Faculty of Building Services Engineering--Technical University of Civil Engineering Bucharest.  
The container was characterized by low thermal inertia but with relatively good thermal insulation according to the data in Table 6.  
The same type and number of measuring devices were mainly used as in the previous experimental study (see Table 1 and Figure 1). Their position was mostly the same, too (e.g., thermocouple's location within the GTC; see Figure 1). The sensors of the weather station were installed on the left corner of the container in order not to influence or obscure the measured parameters (Figure 7).  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Envelope Component** & **Thermal Resistance (m\({}^{2}\)\({}^{\circ}\)C/W)** \\ \hline wall & 1.47 \\ floor & 0.30 \\ roof & 1.47 \\ window & 0.59 \\ door & 0.82 \\ solar wall & 1.33 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Thermal resistance—container envelope components.  
Figure 6: GTC on the facade of the experimental building.  
Figure 7: Installation of the weather station sensors on the container.  
The data acquisition was achieved this time using a much larger storage memory data logger (Almemo 5690-2) to allow the monitoring over longer periods of time. The data logger and the fan power supply were installed in the container, next to the GTC (Figure 8).  
The experimental building was equipped with an air conditioning unit (2.6 kW capacity)--Figure 9. This equipment is used for the heating of the experimental building, operating in \"air-to-air\" heat pump mode.  
A Strohm power meter socket was employed to record the energy consumption of the air conditioner during the experimental investigations (range: 1-3680 W; uncertainty: \(\pm 1\%\)).  
The value of the airflow rate through the GTC is correlated with the required fresh air of the experimental building. Consequently, the imposed airflow rate was 72 m\({}^{3}\)/h, meaning 2 h\({}^{-1}\)ACH (air changes per hour)--suggested outdoor air ventilation rate [56]. In order to achieve this low airflow rate, the GTC was equipped with an EBM-Papst 4184N/2X variable-speed fan and Rohde & Schwarz HMP2020 programmable power supply (output voltage 0-32 V DC; output voltage resolution 1 mV; voltage stabilization \(\leq\) 0.01% + 2 mV;  
Figure 8: Installation of the data logger and the fan power supply in the container.  
Figure 9: Air conditioner.  
output current 0-10 A; output current resolution 1 mA; and current stabilization \(\leq\) 0.01% + 250 uA)--Figure 8.  
The objective of the experimental study was to compare the energy consumption for ventilation of the experimental building (container) without/with a GTC. The measurements were performed in April-May 2021. It should be specified that no experimental investigations were conducted during rainy days.  
Finally, in order to facilitate the comparisons, the GTC was completely covered by a white panel (with the exception of air intake) to study the configuration without the GTC (Figure 10). In this way, equivalent operating conditions were obtained for ventilation (the same airflow rate, pressure loss, and therefore, similar fan energy consumption).