This synthesis sets out design principles for air filtration in swine facilities, covering positive and negative pressure approaches, filter bank placement, seal requirements, and infiltration management. It carries the 5.5 percent sampling rule for positive pressure barn filter banks and states the Dee 2009 result correctly, at 2.92 miles or 4.7 kilometres, with virus remaining viable at that distance.
It functions as an entry point to the primary literature rather than as a substitute for it. The engineering framework for positive pressure design comes from Ramirez and Hoff in 2016, covering fan selection, static pressure budgeting and filter bank sizing. The siting evidence comes from Smith, Holck and Carman in 2019, who found that placing a filter bank near an exhaust outlet significantly reduced filter lifespan and who established the 5.5 percent sampling proportion as representative. The efficacy case comes from Desrosiers and Cousin in 2023 and the herd studies behind it.
One figure requires care where this material is used alongside its companion sheets. The confirmed outer distance for infectious PRRSV recovery is 9.1 kilometres, reported by Otake and colleagues in 2010. The 9.2 kilometre figure that appears in some derived material belongs to Mycoplasma hyopneumoniae from the same study, not to PRRSV. Both organisms were recovered at distance in that work, and the two results are separate. Anyone building a case from secondary design guidance should check the distance figures against the source papers before they are quoted.