Altis G5: A Deep Dive into Thermal Control and Wind Resistance for High-Performance Lighting

Throughout the development process of Thorn’s powerful Altis G5 floodlight solution, many critical factors were taken into account - wind resistance and thermal management being two key considerations.

Thermal management is crucial as it ensures the luminaire operates within safe temperature ranges. Without proper thermal control, the lifespan and performance can be significantly impacted.

Altis G5’s unique pin block heatsink design optimises the product performance and protects the luminaire from the forces of nature. With up to 256,000 lumens available, Altis G5 is often installed within sports, industry, and transportation applications at high levels, where wind speeds can become a powerful force and this added protection is a must.

We spoke to Thorn’s Principal Engineer for Thermal Management, Pier Angelo Favarolo to discuss the importance of the Altis design details and how the team at Thorn has considered every aspect to ensure optimal performance and durability. 

What are the thermal challenges when it comes to managing up to 256,000 lumens delivered by Altis?

“To manage such a high luminous flux we have worked on different aspects of Altis. On the one hand, the high optical efficiency of the luminaire guarantees that light absorbed into the luminaire and converted into heat is kept to the absolute minimum. On the other hand, the heat generated by the LEDs needs to be dissipated efficiently to allow all components to operate within the required temperature range.”

How was thermal management optimised in the development of Altis G5?

The whole cooling chain of Altis has been revised for this latest generation of Altis G5, from the LED module to the heat sink. The heat sink has been redesigned from scratch in order to improve performance and efficiency and to allow the installation in different positions. Many technical investigations were conducted to define the pin block concept for the Altis G5 heatsink design. We then optimised the geometry of the pins, both their individual size and shape and the overall layout pattern, to improve the airflow and to offer the customer the possibility to install the luminaire in different positions.

How was windage optimised in the development of Altis?

The shape of the luminaire and of the pins was optimized to reduce the drag forces. This design means less impact force on the luminaire solution from high winds, and therefore less mounting infrastructure needed to be able to install the Altis G5 at height. Furthermore, one of the unique features of Altis, is the possibility of tilting independently every single light module. Whilst this is key to add flexibility to the lighting design, especially for a sports field where each module can be specifically angled and adjusted on site, this feature is also critical to offer the possibility to optimize the configuration of the luminaire by reducing the drag area. As a result of the in-depth development process which led to the unique design of the Altis G5 pin block heatsink, we are very proud to have been granted an IP patent for this feature.

How did thermal optimisation influence the design of the Altis remote gearbox?

The Altis power supply is a compact unit that must deliver approximately 1.8 kW to the LED modules. Although the driver is very efficient, it still generates some heat that needs to be dissipated. Conventional units usually use longitudinal fins to dissipate this heat. Such a geometry has some disadvantages because it only works effectively in a few positions. For the Altis G5 power supply, we developed a unique heatsink design we call fish-bone, which is designed to work effectively in all positions, giving the customer many installation options and supporting ease of installation.

Why is windage important for sports applications?

Windage (or draft) is the force generated on an object by the wind blowing on it. Outdoor luminaires are exposed to various weather conditions, including high winds. Windage forces can exert significant pressure on the luminaire, potentially causing damage or even failure if not designed accordingly. Furthermore, reducing the impact of windage can reduce the demand on mounting infrastructure, such as poles and columns. Windage optimisation can deliver a major cost saving to customers.

What does SCx mean and how is it calculated?

SCx (drag area or windage area) is a relevant parameter when considering windage on outdoor luminaires and is the product between two quantities: S and Cx.

S: This represents the projection area (expressed in square meters) of the luminaire when viewed from the direction of the wind. It's essentially the silhouette of the luminaire as seen by the wind.

Cx: this is the aerodynamic drag coefficient. It's a dimensionless number that quantifies the resistance of an object to motion through a fluid. A lower Cx indicates a more streamlined shape with less wind resistance. This quantity only depends on the shape of the object and not on its dimensions. For example, two spheres with different radius have the same drag coefficient.

For this reason, the SCx takes into account both the shape (Cx) and the dimension (S) of the luminaire.

How do you create project-specific windage calculations?

As part of our services package available, the use of CFD (computational fluid dynamics) software allows Thorn to test and optimize the configuration of Altis (i.e. the tilt of the frame and of every single light module) by minimizing the SCx in accordance with the desired light distribution. This approach is very important for refurbishment projects to ensure that the existing mounting systems are adequate to hold the new luminaires.

By carefully considering both thermal management and wind resistance, Thorn's Altis luminaire sets a new standard for outdoor lighting in challenging environments. With a unique design that has been granted two IP patents that ensure longevity and adaptability, Altis not only delivers great lighting performance but also provides peace of mind to customers who require reliable and efficient solutions for sports venues. In-house Thorn R&D is a huge asset to our services package, offering customers the chance to have calculated and optimised thermal and windage performance as part of a turnkey solution. As Thorn continues to innovate, the future of outdoor illumination looks brighter than ever.

For more information on Altis, visit the product page.

Thorn Lighting been involved in sports lighting for years. From lighting the most prestigious stadiums in the world, to transforming communities with small projects at local tennis clubs and athletics tracks. Find out more in our dedicated space for Sports Lighting.