Variabilities in determining air exchange rates in naturally ventilated dairy buildings using the CO2 production model

Sensitivity studies on the calculation of AER were performed by varying the indoor and outdoor sampling points, sampling duration and animal parameters used for the calculation. The sensitivity results were compared to the best available data approximation (BADA), which is based on the best knowledge of these parameters. All factors were evaluated and ordered in terms of their influence on AER calculation and uncertainty. The results show that the sampling duration and the number and location of indoor sampling points have the largest effects on AER uncertainty. Data on milk yield and days since insemination have the lowest influence on AER uncertainty. The information collected in this long-term study is very important for planning measurement campaigns in the future.