Ventilation System Requirements for Conversion to Group Sow Housing
The animal environment and energy costs all are impacted by ventilation. When converting to a group-housed sow barn, retaining the existing ventilation system leads to over-ventilation in winter as they are designed for a higher animal density. This can chill the animals with negative impacts on performance and also increases energy costs as it is being overventilated by 33%, with energy consumption raised by 75%. Unfortunately reducing the ventilation does not work as the system needs reconfiguration in order to ensure proper air distribution throughout the room. Under-ventilating creates an unhealthy environment with increased levels of ammonia and carbon dioxide. In order to have a balanced environment, careful re-design of the existing ventilation system must occur. The horizontal flow ventilation system with air inlets on one side and exhaust fans on the other had the best performance. In-barn evaluation showed a 21% reduction in natural gas consumption during heating season and 14% reduction in electricity consumption relative to the unmodified ventilation system.