## 4 Results and Discussion  
Table 2 shows the numbers of the measurement series, measurement duration, average temperatures and relative humidity values in the garage, the number of air changes, and average and maximum values of carbon monoxide concentration in the analyzed garage. The average values of carbon monoxide concentrations presented in Table 1 refer to the first 15 min and the entire 1 h period of the carbon monoxide recording. During the measurements, the average temperatures inside the garage ranged from 8.86 \({}^{\circ}\)C to 12.11 \({}^{\circ}\)C (Table 2) and the average air humidity values ranged from 47.95% to 88.30%. The garage was unheated. In Series 1, measurements were made without ventilation, with the supply fan turned off and the exhaust duct closed. Due to the permissible standards [38] of carbon monoxide concentrations in rooms where people stay, all one-hour average values of the measurement series do not meet the WHO assumptions [38]. In the case of a fifteen-minute measurement period, only Series 6 and 7 meet WHO standards [38] in terms of carbon monoxide concentrations. In the case of the NAAQS standard [37], only Series 7 meets the guidelines for permissible indoor concentrations for a one-hour interval. Figure 1 shows the relationship between the average hourly and maximum carbon monoxide concentrations as a function of the number of air changes for the range of air changes from 6 to 73 1 h measurement series with ventilation turned on (Series 2-7). The relationship between the average hourly and maximum carbon monoxide concentrations as a function of the number of air changes in the garage can be approximated by a power \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & & & & & **Average CO** & & \\
**Series** & **Measurement** & **Average** & **Average** & **Number of** & **Concentration** & **Average CO** & **Maximum** \\
**Number** & **Duration** & **Temperature** & **Relative** & **Per Hour** & **Measurement** & **Concentration** & **Value of CO** \\  & & & & & & **Period** & **over 15 min** & **Concentration** \\  & & & & & & **\(\epsilon_{\text{exp(avg)}}\)** & **\(\epsilon_{\text{exp(max)}}\)** & **\(\epsilon_{\text{exp(max)}}\)** \\ \hline - & **min.** & \({}^{\circ}\)C & **\%** & **1/h** & **ppm** & **ppm** & **ppm** \\ \hline Series 1 & 60 & 8.86 & 83.45 & 0 & 1151 & 350 & 2253 \\ Series 2 & 60 & 10.59 & 88.05 & 6 & 277 & 163 & 356 \\ Series 3 & 60 & 11.86 & 82.10 & 8 & 223 & 150 & 265 \\ Series 4 & 60 & 12.11 & 88.30 & 10 & 177 & 125 & 226 \\ Series 5 & 60 & 12.09 & 54.60 & 17 & 113 & 95 & 142 \\ Series 6 & 60 & 11.24 & 47.95 & 37 & 55 & 58 & 85 \\ Series 7 & 60 & 9.97 & 77.31 & 73 & 29 & 24 & 48 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Parameters of the measurement series: measurement duration, average temperature and relative humidity, number of garage air changes, average and maximum air concentrations of carbon monoxide. function. As the number of the air changes in the garage decreases, the carbon monoxide concentration in the garage increases. Figure 2 shows the dependence of the carbon monoxide concentration as a function of time and the number of air changes in the garage. With the ventilation turned off (Series 1), during the 60 min measurement, a linear increase in carbon monoxide in the garage was noted and did not stabilize in this time interval. After 60 min, the concentration of carbon monoxide was approximately 2253 ppm, which constitutes a direct threat to human life [36; 37]. In the case of an operating exhaust ventilation (Series 2-7), carbon monoxide increases first, and then the carbon monoxide concentration in the garage stabilizes to a constant value. The stabilization time depends on the number of air changes. The stabilization time of the carbon monoxide concentration decreases with an increase in the air changes in the garage.