# Improvement of the Chimney Effect in Stack Ventilation
## 3 Measurement Setup and Equipment  
The measurement system was designed for the constant monitoring of indoor climate conditions, ambient climate conditions and airflow velocity in vent inlets and outlets. It included sensors, port data acquisition modules, a network switch and a PC computer (Figure 6). All sensors were wired directly to the data acquisition modules which registered the measured data, which in turn were connected to the PC computer via a 16-port Ethernet Switch. The measurement data management software LBX 2012 of LAB-EL [13] was installed on aPC computer. The data collected in the module data acquisition was automatically transferred to the SQL database located on a PC computer. The sensors and the data acquisition modules worked in a real-time mode, while the data management software was synchronized with the data acquisition module at each probe time step. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Element** & **Thickness** & **Thermal Conductivity** & **Emissivity** \\  & **d [m]** & \(\lambda\) [W/mK] [12] & **e [—]** \\ \hline Window joinery & 0.024 & 1.4 & 0.95 \\ External wall & 0.38 & 0.77 & 0.84 \\ Chimney wall & 0.12 & 0.77 & 0.84 \\ Glass wall & 0.005 & 6 & 0.95 \\ Air gap & 0.04 & 0.025 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The material and thermal parameters of the partitions in the ventilation system. Figure 6: The measurement system in the test building. The test apartment was divided into rooms with lightweight internal walls. The door between the rooms was open. Air velocity and temperature were registered in the vent inlet (V1 and T1) and outlet (V3 and T3). In the indoor zone, indoor climate conditions were monitored and measured. Air temperature (T2) was measured in the kitchen. The barometric pressure was registered in the kitchen (P2). All sensors were located in the rooms at the height of 1.6 m from the floor level. Thus, proper information about realistic climate data of the local climate conditions is important [14]. A Local Climate Station was built (WDTI6);the climate station measured wind velocity W [m/s], wind direction WD [\({}^{\circ}\)], pressure P [Pa], relative humidity H [%] and temperature of the ambient air T\({}_{\text{amb}}\) [\({}^{\circ}\)C] as well as solar radiation I\({}_{\text{sol}}\) [W/m\({}^{2}\)]. To perform the measurements, components of the LAB-EL products line [13] were used. At the climate station, the omnidirectional wind anemometer LB-747 with the measurement range of 0.5 m/s to 90 m/s and accuracy of 2% was used. The omnidirectional wind anemometer LB-747 of the climate station was located on the roof of the building at the height of 9.69 m above the ground level and 2.05 m above the roof ridge. The barometric pressure was measured with LB-716, which worked in the absolute pressure mode within the range of 2-200 kPa and accuracy of \(\pm\)0.5 kPa. Temperature and relative humidity were measured with the thermo-hygrometer LB-710R. Its temperature range was \(-\)40-85 \({}^{\circ}\)C with the accuracy of \(\pm\)0.1 \({}^{\circ}\)C and its relative humidity range was 99% with the accuracy of \(\pm\)2.0%. In the study, the visible radiation sensor type LB-901 (LITE2--Kipp&Zonen - The Netherlands) was used, with the measurement range of 0 W/m\({}^{2}\) to 2000 W/m\({}^{2}\) and an accuracy of 5%. In the indoor zones, barometric pressure was measured with LB-750, which worked in the absolute pressure mode within the range of 0.1-120 kPa and accuracy of \(\pm\)0.1 kPa. The CO2 concentration was measured with LB-854 sensors. They measured the range of the CO2 concentration from 0-10,000 ppm (accuracy \(\pm\)5%) and of the temperature from \(-\)15-100 \({}^{\circ}\)C (accuracy \(\pm\)0.2 \({}^{\circ}\)C). Air velocity and temperature were registered in the vent inlet and outlet. Due to complex airflow characteristics in the vent inlet (long rectangular shape) and potential flow direction changes, the air velocity measurement was difficult.