Abstract: A fan enclosure that has manifolds connected to the inlet and outlet of the fan that provides an airtight connection. The manifolds, once connected to the enclosure, provide a pass through of the enclosure for the fan, thereby not requiring the enclosure to be pressurized. A condensate bypass can be installed both on the discharge manifold and the fan impeller body. Both condensate bypasses can be piped to the inlet manifold, preventing moisture accumulation in the fan and the enclosure. The fan enclosure helps prevent contamination and explosive gas in the air stream from coming in contact with the fan motor's electrical components and bearings. The fan enclosure reduces the contamination of the impeller bearing, does not draw or push air through the electrical conduit connected to the enclosure, and the enclosure is not required to be airtight to preform properly.