Why would you not go the other way with the fans now that it is in cased in a room? Suck the air through the miners and exhaust them to the outside?
Focused inlet with filters make an over-pressure in the whole building, and all the outlets can be whatever gaps etc.
Reverse things and you will have unfiltered (dusty) air seeping in everywhere, not very nice in the spring with all the pollen in the air.