Using an air filtration system has been shown to be effective in reducing the risk of PRRSv contamination, but high clogging rates make maintenance and cost impractical in most commercial barns. This study tested the effect of various prefilters at the exhaust outlet, and the effect of ionizing systems. The study took place in a 108 gilt quarantine barn, and spanned 25 days (except for one 35 day trial). The inlets were  equipped with a 15 layer Noveko antimicrobial filter. The outlets had either a StuffNix prefilter with an ionizing system, StuffNix without ionizing, MERV-13 prefilter with an ionizing system, or MERV-13 without ionizing. Following one of those options was a  Noveko prefilter, and then a 10 layer Noveko antimicrobial filter. An ionization system reduced particle concentration by 43-60%, total bacteria by 83%, and dust mass concentration by 64%. The StuffNix prefilter reduced dust mass concentration by 29-38%, quantity of particles by 3-39%, and total bacteria by 6-9%. The MERV-13 prefilter reduced dust mass concentration by 47-80%, quantity of particles by 81-96%, and total bacteria by 89-96%. With the StuffNix prefilter, the prefilter did not clog, but the antimicrobial filter did. The MERV-13 prefilters performed well in autumn conditions, as both the prefilter and the antimicrobial filters did not clog. The MERV-13 system with the ionizer filter a different quantity of air than without an ionizer, so cannot be compared. For this study, it was determined installing a filtration and ionizing system would provide a savings if the other option was to build a detached quarantine unit. Overall, the MERV-13 prefilter and antimicrobial filter system was the most effective at filtering out dust and bacteria, and remaining unclogged. However, additional studies in summer conditions, and to compare using an ionizer or not will need to be conducted.