Energy-efficient enclosure cooling in cool but dusty environments

>Air/air heat exchangers recirculate the air inside the enclosure, cooling it using the cooler ambient air which is passed over a cross-flow heat exchanger. The two air flows are kept entirely separate, thus ensuring any dust, dirt or other contaminants are kept away from the electrical or electronic equipment.  

>The greater the difference between the internal and external air temperatures, the more heat may be removed from the cabinet.

>Rittal air/air heat exchangers need less maintenance than fan-and-filter units, in part thanks to their individual controls for the internal and external fans and easy-to-remove cassettes. The internal temperature within the enclosure is also constantly displayed so users can tell at a glance that the unit is operating optimally.  If temperatures within an enclosure get too high then a floating fault signal will sound to alert the user immediately about an impending problem.