One of the limits to the development of LED technology is certainly heat dissipation. In the LED, as there is no infrared emission, this occurs only through its body, from this to the printed circuit, from the printed circuit to the radiator and finally to the environment; the first phases occur by conduction and the last by conduction, convection and radiation.

The considerable energy required for ambient lighting and the thermal transmission chain constitutes a limit to the size and power of the lamps; just look at the research efforts underway to reproduce old incandescent lamps with LEDs.

In street and industrial lamps, as there are no major limits to size, this problem does not exist; however, the most commonly used solutions, also due to their simplicity, present some limitations, let’s take for example the case of an LED lamp whose heat dissipation principle is shown in the drawing below:

If we consider a product with an interdistance between LEDs of 25mm, the radiation surface is approximately 51cm² per LED, equivalent, in the case of LEDs from 1.25W to 40cm2/W. This value is sufficient if the entire 40cm² surface is capable of transmitting heat by radiation, conduction and convection but this is not what happens in the type of radiator illustrated. Regarding radiation, in fact, the fins influence each other because the emission of each one ends up on the others, reducing efficiency by over 50%. Regarding conduction/convection, the air circulation, which occurs mainly from the bottom upwards, inside the fins is almost non-existent with a consequent reduction in efficiency of 60/70%.

Overall, the finned radiator loses between 55% and 60% compared to the exposed surface, so the theoretical 40 cm²/W is reduced to a real 15 cm²/W, i.e. well below the optimal value.

In addition to this, heat sinks finned upwards become a receptacle for dirt and, in the case of the presence of birds, they could almost completely lose their dissipation characteristics, not only that, all heat sinks that expose the dissipating surface exclusively upwards, they are extremely critical during summer days. The radiator, placed under the sun for many hours, reaches temperatures even higher than 100° with consequent serious problems for the LEDs. Let’s not talk about the case in which, for unforeseeable reasons, the lamp were to remain on during a sunny summer day, in this case the temperature of the LEDs could exceed 150° with consequent damage to them.

From our 40 years of experience in this field we have created a patented solution which integrates the heat sink into the lamp body and, in addition to providing a notable dissipation surface, avoids all the problems described. As can be seen from the drawing, the lamp body, entirely made of aluminium, surrounds the printed circuit that carries the LED, also made of aluminium, and dissipation occurs in all directions.