The packing density in enclosures is increasing and calls for high-performance climate control systems. One economical way to dissipate heat loads with the aid of ambient air from the enclosure is the use of fan-and-filter units - a combination of fan and dust filter. By developing a new high-end variant of it TopTherm fan-and-filter series, which is now available as a complete EC version, Rittal offers more opportunities for ventilating enclosures in an energy-saving way. They are equipped with pressure-resistant diagonal technology, as well as intelligent control and monitoring functions. The unit has brushless DC motors that have 2.5 times more motor efficiency than the conventional shaded-pole motors used in fan-and-filter units. Due to the electronic conversion (commutation) of the AC into DC voltage, the speed of the fan can be controlled by voltage regulation. The EC solution permits energy savings of up to 63 percent compared to a standard AC fan-and-filter unit with a shaded pole motor. Further savings are possible by means of an infinitely variable speed control with an interface built into the fan. The control of the fan with 0 to 10 V or a PWM (pulse width modulation) signal is performed either via the Rittal EC controller or by a PLC (programmable logic controller). The optional EC controller, which can be mounted on a top-hat rail offers a range for setting the target temperatures (5° to 55°C), an external temperature sensor to measuring the actual temperature, and a status LED to indicate the operating status. In addition, an alarm relay reports such errors as over-temperature, fan defect, circuit interruptions, and sensor breakage. Up to four EC fan-and-filter units can be connected to the control unit.