The air quality ofbroiler cagesis mainly affected by the content of harmful gases and dust. Harmful gases and dust seriously affect the health of chickens. Controlling the air quality of the chicken farm is a key part of safe production. The dust in the house is mainly derived from the skin and feathers of the chicken, as well as the droplets generated during coughing and tweeting. However, the source of dust in flat and caged chicken houses is different, and the grass in the flat chicken house can also produce a large amount of dust.

The requirement for ventilation in the house is that it does not affect the temperature inside the house and keeps the harmful gases in the house to a minimum. The amount of ventilation is determined according to the heat balance calculation and the control requirements of the harmful gas concentration. The gas exchange amount of the house can be calculated according to the total weight of the final chicken, that is, the ventilation required per kilogram of chicken weight is calculated as 0.115m3/min. This is used to calculate the number of air purifiers required.