Systems and apparatuses include an apparatus including an intake defined by an intake aperture, an intake baffle, and an intake floor structured to couple to an intake portion of an enclosure roof, the intake extending along at least eighty percent (80%) of a width of the apparatus on a first side, an exhaust defined by an exhaust aperture, an exhaust baffle, and an exhaust floor structured to couple to an exhaust portion of the enclosure roof, the exhaust extending along at least eighty percent (80%) of the width of the apparatus on a second side opposite the first side, a partition panel isolating the intake from the exhaust, and an engagement mechanism structured to couple the apparatus to a generator set.