Moisture balance and tracer gas technique for ventilation rates measurement and greenhouse gases and ammonia emissions quantification in naturally ventilated buildings

Experiments were performed to study the ventilation rates in a naturally ventilated animal building through four summer seasons and three winter seasons. The ventilation rates were determined using moisture (H2O) balance, tracer gas technique (TGT) and CO2-balance. The statistical analyses were correlation analysis, regression model and t-test. Continuous measurements of gaseous concentrations (NH3, CH4, CO2 and N2O), temperature and relative humidity inside and outside the building were performed. The H2O-balance showed reliable results through winter seasons and acceptable results to some extent through summer seasons. The CO2-balance showed unexpected high differences to the other methods in some cases. The TGT showed reliable results compared to H2O-balance and CO2-balance. The air exchange rates (AERs) were 37.2, 61.6 and 63 h−1 through summer seasons, and 40.3, 38.9 and 60.5 h−1 through winter seasons subject to H2O-balance, TGT and CO2-balance, respectively. The emission rates through summer seasons, subject to TGT, were 191, 855, 73,877 and 45.6 g d−1 AU−1; and through winter seasons were 88, 463, 55,976 and 47.3 g d−1 AU−1, for NH3, CH4, CO2 and N2O, respectively.

► The H2O-balance showed reliable results through winter seasons and slightly acceptable results through summer seasons.
► The CO2-balance showed unexpected high differences to the other methods in some cases.
► The tracer gas technique showed reliable results compared to H2O-balance and CO2-balance.