Embodiments of an enclosure assembly to enhance cooling of a hydraulic fracturing direct drive unit (DDU) during operation are included. The enclosure assembly may include an enclosure body extending at least partially around an enclosure space to house the DDU for driving a fluid pump. The enclosure assembly may include one or more heat exchanger assemblies connected to the enclosure body for cooling a process fluid associated with one or more of the DDU and the fluid pump, and which may be configured to draw air into the enclosure space from and external environment, toward one or more radiator assemblies to cool the process fluid, and along an airflow path through the enclosure space. One or more outlet fan assemblies may be operative to discharge air from the enclosure space to the external environment to maintain a desired temperature of the enclosure space.