Ammonia control by ventilation in semi-closed type poultry house

The objective of the present study is to control NH3 gas by ventilation in semiclosed type poultry house and to analyze the NH3 control effect of ventilation through experiments. The authors performed experiments in a commercial semi-closed type poultry house in summer, autumn and winter season. In summer season, eight ventilating fans were operated continuously all day for the purpose of lowering the inside air temperature. As the results, the NH3 gas concentration was kept enough low (4-7ppm). In autumn season, two or four ventilating fans were operated almost continuously. The NH3 gas concentration was about 6-10ppm. In winter season, ventilation was limited in order to keep the inside air temperature above 15 degrees C. Two or three ventilating fans were operated for only about fifteen minutes per hour in the nighttime. NH3 gas concentration of 36ppm was observed when the ventilating fans were not operated. On the other hand, the fifteen minutes ventilation brought about decrease of 10-15ppm in the NH3 gas concentration, indicating the NH3 control effect of ventilation in poultry house.