# Improvement of the Chimney Effect in Stack Ventilation
## 2 Test House  
The test building wasa two-store, two-apartment residential house located in Gdansk (northern Poland), a region of cold climate. The apartment, with a floor area of approximately 50 m\({}^{2}\), was selected for the measurement campaign (Figure 2a). The apartment was located on the first floor and consisted of a bathroom, bedroom, kitchen, living room and corridor. To simplify the ventilation system configuration, the bathroom, bedroomand corridor were excluded from the measurement space and isolated from the rest of the apartment (Figure 2b). The indoor test space was limited to the kitchen. The test apartment was inhabited during the measurement campaign. The residents' activities were registered mainly in the morning and in the evening (after 5:00 p.m.). The test house was a heavy-weight building. The floor slabs were made of concrete. Stone materials are used for both sides of the cavity walls. The building was erected in the 1950s and thermally renovated in 2012. Table 1 provides the U-values overview of the main structural components. The test apartment was equipped with astack ventilation system in configuration with air inlets and chimneys ducts. Air inlets are small appliances mounted in the casement or window frame, which enablecontrol of the fresh air inflow to the room. They were invented and introduced in the 1960s in Scandinavian countries [12]. In Poland, this type of inlet gap (Figure 2(a)) is obligatory in the case of usage of stack ventilation in configuration with multi-chimneys ducts. The air inlet into the chimney duct was equipped with a controllable vent grill, which was located 0.15 m below the room ceiling. The measurement system was limited to the kitchen (Figure 1(b)) with a usable area of 15.75 m\({}^{2}\) and an air volume of 40.95 m\({}^{3}\). The configuration with one air inlet (rectangular inlet gap in a window frame) and one air outlet (a chimney duct in the kitchen) allowed for the reduction of the unknown parameters influencing the air exchange process. The used air was removed through a vent with dimensions of 0.14 \(\times\) 0.14 m (Figure 2(b)). During the measurement timeperiod, all windows were closed. The doors inside the test apartment were closed during the nighttime and during the residents' worktime. \begin{table}
\begin{tabular}{c c c} \hline
**Element** & **Details** & **U-Value** \\ \hline \multirow{2}{*}{External wall} & Cavity wall with (inside to outside): limestone inner layer, thermal insulation, brick outer layer & 0.18 W/(m\({}^{2}\)K) \\ \multirow{2}{*}{Door} & Wood & 1.10 W/(m\({}^{2}\)K) \\ \multirow{2}{*}{Windows} & Double panel glazing & 0.90 W/(m\({}^{2}\)K) \\ \hline \end{tabular}
\end{table} 
Table 1: Overview of construction details for the base case building from 2012. Figure 2: The residential family test house: (**a**) vertical section and (**b**) cross-section of the first floor. In the test room, there was a single-chamber PVC window with dimensions: 4/16/4 [mm]. The room had two doors, each leading to a heated room. While the residents were not present, the door was tightly closed. The chimney was made withtraditional technology, with full ceramic brick. This is a description of TYPE I (Figure 4). The chimney protruded above the roof slope to a height of 1.04 m. The building wall was made of solid ceramic bricks with a total thickness of 0.38 m. Partition walls weremade of solid ceramic bricks, 0.12 m thick. In TYPE II, parts of the chimney protruding above the roof surface were enclosed with a transparent wall (float glass) with an air gap thickness of 0.04 m (Figure 4(a)). Glass with a thickness of 5 mm was used for the housing. In TYPE II, the remaining elements of the ventilation system did not change. The material and thermal parameters of the partitions in the ventilation system are presented in Table 2.  
Figure 4: Test room and stack ventilation system, TYPE I.  
Figure 5: Test room and stack ventilation system, (**a**) TYPE II, (**b**) TYPE III. Figure 3: Inlet gap (**a**) and outlet vent (**b**) in research.