Mimicking Indoor Climate Dynamics and Ammonia Emissions in a Pig Housing Compartment Using Artificial Pigs and an Automatic Urea Spraying Installation

Abstract

The study aims to develop a test platform (TP) compartment that could mimic diurnal variations in indoor climate and NH₃ emission in a real pig compartment and to compare diurnal indoor climate and NH₃ production between two TP compartments and a real compartment. The objectives were achieved by using a real and TP compartment followed by an ad hoc test that used two TP compartments and another real compartment. The TP had two compartments equipped with mock-up pigs as heat source and automatic urea solution spraying installation to mimic pig urination at the pen floor. The study evaluated indoor climate and NH₃ production in a 4-day comparative test between a TP and a real compartment followed by a 3-day comparative test between two TP compartments and a real compartment where exhaust and slurry pit NH₃ concentrations, ventilation rate, indoor temperature and relative humidity were simultaneously measured. The TP reproduced comparable diurnal measured parameters in the real compartment. The TP compartment overestimated NH₃ emissions in the real compartment by 23% (R² = 0.27) in the first experiment. In the second experiment, the two TP compartments overestimated NH₃ emissions in the real compartment by 38% (R² = 0.36) and 44% (R² = 0.37). The overestimated NH₃ emission in the TP was probably due to differences in urea solution vs. pig urine chemistry and floor fouling characteristics. The two TP compartments when compared showed similar diurnal trends in NH₃ concentration and emission rate with hourly averages of 11.5 ± 4.1 vs. 11.6 ± 2.8 ppm and 13.2 ± 3.0 vs. 12.1 ± 2.9 g/h, respectively. The study shows the TP could simulate indoor climate dynamics and NH₃ emissions trends in a real compartment and therefore could be used to study NH₃ volatilization processes and emission reduction techniques studies on relative emission basis.