The Centre de développement du porc du Québec has compiled a fact sheet to give an overview of air filtration. Two studies from the University of Minnesota are summarized. The first study demonstrates that the effectiveness of an air filtration system to keep out pathogens also relies on good biosecurity procedures. Secondly, the type of air filter used was shown to be inconsequential on effectiveness. Two things to consider when choosing an air filtration system are the filter type and the air inlet type. The filters can either be mechanical or antimicrobial; and the air inlet type can be lateral, modular ceiling, or continuous linear. To make an air filtration system effective unfiltered air has to be prevented from entering, so the building should be as air tight as possible. Fan shutters can be made air tight by the use of an anti-backdraft system: a home-made air-chute, or a NoBackDraft damper are two options. Other topics such as cost and the impact on ventilation are also addressed in the fact sheet.