Scaled experimental study of a ventilation system featuring partition jet and pit exhaust

In the context of current intensive livestock farming development, we present a novel energy-efficient ventilation method, named as the partition jet and pit exhaust (PJPE) system, for multi-story pig facilities. The objective is to overcome the limitations of traditional ventilation methods, e.g., mixing ventilation sidewall air supply or tunnel ventilation, in managing heat stress and air quality. Isothermal and non-isothermal experiments were conducted in a 1:2.5 scaled pig pen model to study the airflow distribution characteristics and ventilation effectiveness of the PJPE system. The results demonstrate that the PJPE system enables rapid delivery of fresh air to the animal-occupied zone (AOZ). With the Archimedes numbers (Ar) of supply air ranging between 0.0025 and 0.0052, the jet maintains low air temperatures near the pig's back. Compared to traditional pig house ventilation methods, the PJPE demonstrates better heat removal efficiency (HRE), with an average HRE of 1.20. Additionally, the PJPE effectively inhibits the upward diffusion of ammonia from the slurry pit. These findings indicate that the PJPE system presents a viable, energy-efficient alternative for environmental control in high-density pig housing, highlighting its potential for advancing animal welfare and productivity in intensive livestock farming.