You likely don't need the fan. Hot side/ cool side holes usually will move air by convection all by its self. Racks are a complex arrangement a careful balance between temps airflow and ambient air temps. The fan is fine if it doesn't tank the ambient air temp inside the tubs. Typically very few talk about or understand the important nature of AIR temps. Racks often do not do well in cool rooms so I am guessing yours is heated? if so the fan should be fine if not I'd ditch it.