An embodiment includes a cooling unit, including: a housing configured to attach to an enclosure opening in a sealed manner, where the enclosure houses heat generating electrical equipment; the housing including: a first ambient side area including a compressor, condensing coils, and an ambient air intake and outlet; a first enclosure side area situated above the first ambient side area and including an electrical box that includes one or more relays and a digital controller; a second enclosure side area extending along the rear side of the housing and communicating with the first enclosure side area, including an impeller, an enclosure air intake, an enclosure air return, and evaporator coils in fluid communication with the condenser coils; and a second ambient side area including an impeller and one or more hot air exhausts; where all components of the cooling unit are non-sparking and non-arcing; and where the first and second ambient side areas are sealed off from the first and second enclosure side areas. Other embodiments are described and claimed.