1. An air handler comprising:a first enclosure having a first interior volume;
a plurality of air distribution modules affixed to the first enclosure; and
a controller in operable communication with at least one of the plurality of air distribution modules; wherein each of the plurality of air distribution modules comprises:
a second enclosure having a second interior volume, an upstream end, and a downstream end, the second enclosure configured to be coupled to a conduit, wherein the conduit is to be downstream of the downstream end of the second enclosure; and
a fan disposed within the second enclosure at the upstream end of the second enclosure, wherein the controller is operative to cause the fan to move air through the second enclosure, wherein the fan disposed within the second enclosure is positioned within the first interior volume of the first enclosure.