Magical cave illumination despite the harsh environment with OSRAM’s Duris P5

Just 40 minutes outside of Salerno, the river Negro disappears into a mountain and offers visitors an exciting experience with an unusual boat trip in a magical silence, broken only by the sound of an underground waterfall. The caves stretch for about three thousand meters into the massif of Alburni, where stalactites and stalagmites decorate the caves with stunning shapes and colors.

The Italian lighting specialist Lums was assigned to implement a new lighting system for the caves. The idea was to create a controllable multicolor LED based lighting system (RGBW) including low infrared and ultraviolet – not only to provide an even more colorful experience for visitors, but also to reduce the growth of algae and other unwanted elements inside the caves. This was achieved by using a mix of LEDs with specific wavelengths, especially by adding specific blue light to the mix. In addition the lighting system had to be designed to withstand the environmental challenges of an underground cave with high humidity and water.

To master this challenge Lums’ partner company Phaenomena, a certified OSRAM LED Light For You Partner, developed a new luminaire based on the Duris P5 white and color product line. The Duris P5 LED product family offers superior corrosion resistance for high-quality lighting solutions, and high maximum forward current of 200mA. The long lifetime at high temperatures and high currents (L70/B50 > 50,000h at Tj = 125ºC and If = 200mA) and a high efficacy of up to 110lm/W at 3000K make the LED ideal for high-quality professional lighting applications. The color line is available in “deep blue” (450 nm), “blue” (470 nm), “true green” (528 nm), “yellow” (590 nm) and “red” (615 to 625 nm) featuring a footprint of 2.6 x 2.2mm. At the heart of the different colors are state-of-the-art chip technologies, based on either the InGaN (Indium Gallium Nitrite) material system or InGaAlP (Indium Gallium Aluminum Phosphite) depending on the wavelength.

Phaenomena’s resulting product family Opera is a luminaire line available in different versions able to provide the right solution for different applications: floor, ceiling, wall or swivel. The body of the luminaire is extruded with anodized aluminium. It is equipped with the Duris P5 RGBW LED technology (Red, Green, Blue, White 4000-6000K). The LEDs are individually controllable via a DMX512 interface.

For the application at the Pertosa-Auletta caves this means that the cave guide can change the colors or turn off the light to let visitors experience the cave’s darkness for a few seconds – a feature that has been enthusiastically rated by visitors on TripAdvisor. In addition to the controllable colorful lighting, which enhances the visitor’s experience, the new lighting solution reduces the grown of algae as well as the energy consumption and maintenance costs, due to the long lifetime if the LED based luminaires, significantly.

Visitors are thrilled and have been leaving glowing reviews on TripAdvisor. A German visitor from Bremen says: “I was here 10 years ago and the atmosphere was completely different. The old lighting system was terrible – it has damaged the stones (…) but the new LED lighting system is amazing and provides a breath-taking scene. (..)”

“The project required an enormous engineering effort and the support of a company like Osram Opto Semiconductors” said Angelo Arato, CEO at Phaenomena. “We have chosen the Duris P5 line primarily for its superior robustness even in environments with high humidity typical of marine underground caves due to the innovative package technology.”

“The color Duris P 5 versions give our customers even greater freedom in designing luminaires, including the combination of the white and colored mid-power LEDs within one lamp”, explains Gabriele Giaffreda, Senior Sales Manager, at OSRAM Opto Semiconductors. “The use of the Duris power class also reduces system costs while improving the distribution of light and simplifying thermal management. Partners such as Phaenomena show, how creatively the resulting luminaires can be used to not only enable significant cost reductions for the end customer, but also to create magical illumination settings.”

For more information on the Duris P LED family of products and architectural lighting, visit https://ledlight.osram-os.com/applications/architecture-led-lighting/ and for more information on Phaenomena’s solutions and the project, visit http://www.phaenomena.it/grotte-di-pertosa-sa/

• Video: Grotte di Pertosa Auletta
• Luminaire phOpera