LED technology is fully in line with the trend right now. We encounter little light-emitting diodes more and more in daily life. For good reason: LEDs are significantly more energy-efficient than lightbulbs or halogen lamps – even in energy-saving form – and even have longer service life. Moreover, they have an attractive appearance and can be integrated into modern designs in many ways due to their small size. But where there is light, there is not just shadow, but also heat. In order to dissipate this heat, manufacturers generally use cooling elements made of aluminium. “At high light intensity this strictly passive cooling quickly reaches its limits,” explains Jochen Wolber, Export sales Manager Fans at ebm-papst St. Georgen.
If the lamp is to shine more brightly, the cooling element also needs be enlarged to provide more capacity. “But for many users, this is out of the question,” said Wolber. After all, not only the design would be extremely limited by this, but the weight of a lamp would increase massively – both an absolute criteria for elimination for many applications. As it was in the case of Philips: the electronics firm is currently upgrading existing street lights throughout Europe to LED technology as part of a retrofit. In the existing housings of the lanterns, there are now new insides. The dimensions must not change at all. Therefore, the product designers decided in favour of working together on an active cooling variant with ebm-papst: a small fan dissipates the additional heat, and the cooling element retains its compact size.
The core principle is well known, as cooling computer hardware functions in this manner. “That, however, didn’t help us much”, Wolber admits. “After all, these applications don’t have an especially reliable reputation on the market due to the existence of many cheap products.” In terms of durability above all, potential customers must first be convinced of the quality of ebm-papst products. But even the 90,000 hour service life of the street lamps required by Philips is fulfilled without problems by the axial fan implemented – even in the open air.
It affects industrial lamps even more. The Korean steel giant Posco hangs these in its plants. The dust whirling around does not just ensure that the LEDs with 17,000 lumens at approximately 230 watts have to light extremely brightly. Furthermore, the dust has partly magnetic properties and would quickly attack the electronics and bearings of the ventilation system without the necessary coatings. Working together with ebm-papst, the developers integrated a function in the fan to reverse the direction of rotation. If required the air flow could clean an integrated dust filter. “Such customized developments are not an exception for LED technology, but rather the rule,” explaines Wolber. “We can’t simply reach in the drawer and pull out the finished fan.”
Even applications that at first glance appear simple bring their own challenges. A series of spots from light specialist Zumtobel hang in museums and retail stores, for example. The ambience is, of course, much easier to cope with. However, these lamps have an overall round shape – the traditional square-cut fan housing thus had to be adapted to this form.
The variety of these applications shows how wide the field of applications for LEDs is. “And we find ourselves just at the beginning of the development,” emphasised Wolber. In his opinion, the market will grow even more significantly if the trend of energy-saving lighting spreads world-wide. ebm-papst estimates the growth in the coming years will be about 35 percent.