Heat balance and tracer gas technique for airflow rates measurement and gaseous emissions quantification in naturally ventilated livestock buildings

► The heat balance showed slightly acceptable results through summer seasons and unsatisfactory results through winter seasons. ► The CO 2-balance showed unexpected high differences to the other methods in some cases. ► The tracer gas technique showed reliable results compared to heat balance and CO 2-balance. Experiments were performed to study the airflow rates (AFRs) in a naturally ventilated building through four summer seasons and three winter seasons. The AFRs were determined using heat balance (HB), tracer gas technique (TGT) and CO 2-balance as averages of the values of all experiments carried out through the different seasons. The statistical analyses were correlation analysis, regression model and t-test. Continuous measurements of gaseous concentrations (NH 3, CH 4, CO 2 and N 2O) and temperatures inside and outside the building were performed. The HB showed slightly acceptable results through summer seasons and unsatisfactory results through winter seasons. The CO 2-balance showed unexpected high differences to the other methods in some cases. The TGT showed reliable results compared to HB and CO 2-balance. The AFRs, subject to TGT, were 0.12 m 3 s −1 m −2, 1.15 m 3 s −1 cow −1, 0.88 m 3 s −1 LU −1, 56 h −1, 395 m 3 s −1 and 470 kg s −1 through summer seasons, and 0.08 m 3 s −1 m −2, 0.83 m 3 s −1 cow −1, 0.64 m 3 s −1 LU −1 39 h −1, 275 m 3 s −1 and 328 kg s −1 through winter seasons. The AFRs are not independent values, rather they were estimated for specific reference values, which are: area, cow and LU as well as rates. The emission rates through summer seasons, subject to TGT, were 9.4, 40, 3538 and 2.3 g h −1 cow −1; and through winter seasons were 4.8, 19, 2332 and 2.6 g h −1 cow −1, for NH 3, CH 4, CO 2 and N 2O, respectively.