Field performance evaluation of a ventilation system: A swine case study

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building and how they work as a system. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep-pit swine finishing building with two 1,000-head rooms. Exhaust fans connected to the manure pit and wall fans were operated at various stages as a negative-pressure ventilation system. A computerized controller activated exhaust fans, a ventilation curtain actuator, heaters, stir fans, and a spray cooling system. Gravity-controlled baffled ceiling inlets were evenly spaced in the building to provide good air distribution during cold and mild weather conditions. Following the review of current conditions and operating parameters, performance deficiencies were identified and recommendations were given regarding controller settings, inlet settings, and the transition to natural ventilation. Specific recommendations included changing minimum ventilation speed settings of fans based on animal size, removing inlet stops during warmer weather to avoid premature transition to natural ventilation, a change in how fans were staged, a change in setpoint, and the specific temperature at which the cooling system was engaged.