Following the success of the Stela for mostly residential areas and the T-line for tunnels, Indal introduces a  new LED luminaire for traffic routes. The new luminaire  will enable savings on energy costs and CO₂ emissions from 10 to 40%. Considering that these installations involve high wattages, this adds up considerably. LED is about to experience new levels of success. “We can now offer a suitable LED solution for all situations,” says product manager Wim Visser proudly. “From the smallest alleys to the busiest highways.” The new launch involves two differently sized Luma luminaires: the Luma 2 and the Luma 3.Preview

Next step

LED lighting has the future, an opinion which is getting more support. While developing the new technology, Indal focused first on the Stela. “That was a conscious choice: with its application area – such as residential areas – with the largest potential for energy savings,” explains product manager Wim Visser. “These areas need huge numbers of lighting installations and relatively lower lighting levels. There you achieve your energy targets as quickly as possible. Another important factor was that these luminaires are located in residential areas and are therefore close to people and politics. That’s how we generated approval and acceptance for this new method of lighting – in terms of both lighting and appearance.”

“Then our T-line for tunnels clearly demonstrated the robustness and reliability of our technology. The system complies with all the special requirements (lighting and maintenance) for road tunnels. This took us to the next step: the move from residential areas to motorways. Which is how we arrived at the Luma concept.”

Luma is intended for use on access roads, ring roads, inter urban main roads and motorways. Visser: “Higher lighting levels are required on these roads. Depending on the road type, they now use 50 to 400 Watt SON-T lamps. The challenge was to cover that complete range with the Luma family – and that’s exactly what we did.”

Huge nominal savings

Compared to residential areas, small and efficient lamps are generally already used on traffic routes. Their light is easier to direct and to capture. Moreover, there are strict standards not just for lighting levels, but also for the degree of ambient lighting, so that the available light is utilised more efficiently. Those two factors mean that in percentage terms the energy savings achieved with the Luma are not as high as for the Stela, which often produces savings of over 60%.

However, the Luma is no less attractive. “People tend to focus on the percentages,” Visser explains. “But on traffic routes each lighting point requires higher wattages and therefore the absolute figures are counting. Of course, it’s difficult to generalise given the diverse wattages and lighting situations involved. But going from 50 up to 400 Watt, you can often end up with savings of around 10 to 40% (without dimming). Then we’re talking about huge numbers of kilowatts and enormous amounts of money and CO₂.”

However, certain problems had to be overcome. “In the Stela, the LEDs are positioned with reasonable spacing – at optimal thermal distance. For each LED, you have a particular lighting volume and depending on how much lumen you need for an application, you calculate the required number of LEDs. For traffic routes, you need much more lumen packages and LEDs. If we had kept to the same LED distances as in the Stela, we had ended up with luminaires three or four times bigger. That’s obviously not a practical option.”

Pulling strings…

The optical lighting technology in the Luma is called OPTIFLUX™. ‘Flux’ means flow of light and emphasises the fact that the system involves large lumen packages that are optimally captured with this technology. Three different lens-optics were developed to meet the requirements of the various M(E) lighting classes and road geometries. Those lenses are positioned close to each other, covered with a flat glass bowl. The printed circuit board (PCB) with LEDs is positioned in a white frame. The frame is made of highly reflective plastic and directs the little light that is shining to the side downward in the direction of the road.

Initially, it seemed as if the use of a glass bowl was going to reduce the lumen output per Watt, but during the design process we pulled all kinds of strings and looked at how the effects impacted each other. We kept going until we hit on the perfect balance: the lumen package, the energy efficiency, the size and shape of the luminaire, the operating life time, and so on. One very important choice was to make the bottom of the Luma very flat (with no parts sticking out), so that it complies with the important G4 glare class, where upward lighting must be avoided.

A maximum of 200 LEDs with 40,000 lumen can be installed in the Luma 3. That number is required to replace a luminaire with a 400 Watt SON-T lamp. If a lower lighting level is desired, you can use fewer LEDs or the same number of LEDs at a lower current. This can be done in steps of 20 LEDs every time.

Indal introduces two Luma’s. The Luma 3, at 1 meter length, is the larger of the two and can be equipped with a minimum of 100 and a maximum of 200 LEDs. The Luma 2, at  80 centimetres length, can accommodate a minimum of 60 and a maximum of 120 LEDs. That fits in nicely with the maximum of 52 LEDs in the Stela Wide.

Thermal management

As everybody knows, LEDs can get very hot. That means that extra focus must be directed at the thermal management. The heat development takes place at the back of the LED. A careful choice of thermal resistance, for example, and clever positioning of the LEDs increase the cooling options. If the maximum number of LEDs is not necessary, the LEDs are positioned further away from each other. “We devised the optimal patterns for this. Nowadays we manufacture the PCBs for the LEDs ourselves in our factory in Emmen, so that gives us great flexibility.”

The luminaire housing was designed in such a way (it includes an aluminium temperature buffer) that the heat of the LEDs spreads evenly over the housing. Just like the Stela, the heat is discharged into the open air through the housing. This is called the COO-LED™ principle. To create enough capacity for the heat dissipation, the surface of the top of the luminaire is enlarged with slightly curved ribs. Both the luminaire housing and the ribs are optimally rounded and designed that water easily drains off.

The Luma is fully dust-proof and waterproof and complies with IP 66. Moreover, in closed position, the LED module is protected by an eXtra gasket (XIP).

L-tune: tuning customer’s needs…TRIPLE-C in the best manner

The Luma is equipped  equipped with programmable drivers. The amount of milli-amperes to drive the LEDs can be defined very accurately. Which lumen package do I need exactly? You can build and tune this in several ways. To do this, we developed a calculation tool (L-tune) that specifies the options in Luma depending on the customer’s wishes. With a low current level, you can achieve the highest energy savings and probably also the best Total Costs of Ownership – and it’s also good for the operating life time, of course.

But then you need more LEDs. If you use a higher current, you may achieve your technical lighting requirements with much fewer LEDs. That means that you could get the same result with the smaller Luma 2 instead of the Luma 3. That’s less energy-efficient, but if your investment budget is the deciding factor, it’s probably the best solution.”

“We assess every customer’s situation individually. This methodology fits seamlessly with our TRIPLE-C philosophy – leaving the choice to the customer. So the customer is free to choose the perfect balance between Comfort, Care and Costs.”

CONSTAFLUX

Another new novelty that Visser believes will be very popular among many road authorities is called CONSTAFLUX. This clever system has been made possible thanks to the use of the programmable driver.

Normally, the lumen output of a LED falls back during its life time from 100 to approximately 80%. A lighting design is usually based on the lowest value, in this case 80%. The other 20% of the initial period is therefore actually superfluous lighting and thus wastes energy.

“We approach it differently: we programme the driver based on that 80% as the technical lighting value. At the start, the driver produces less current and gradually increases the current during the operating life time, so that the amount of lumen remains constant. On balance, that means extra energy savings of 25 to 35% on top of the savings made by the Luma itself. “We believe that many customers will opt for CONSTAFLUX, not least because they are sure of recover their investment.”

Fit & Forget

With the Luma, the concept of Fit and Forget is now within reach. Wim Visser explains: “People tend to think in terms of standardised solutions, because lamps always had to be replaced regularly. But with the tuning that we now have, the customer can choose the solution that suits best. In your lighting calculations, you determine how much lumen and which lens-optic you need. Then you can calculate the options; if you want the LEDs to last for, say, 80,000 operational hours, without replacement. Then L-tune presents you with the option of more LEDs and less current, making the system extremely efficient, or the option of fewer LEDs and more current, which is less efficient. It’s entirely up to you which Luma you use, with how many LEDs and on which milli-amperage, and with or without a dimmer and CONSTAFLUX. And that’s exactly how we build the Luma, according to the customer’s specifications in our own factory.”

“When you follow the Fit and Forget philosophy, you are not buying a luminaire – you are buying a system for life. With today’s traffic routes, where the availability of the road is a vital factor and you want to minimise road lane closures for maintenance or replacement activities, there’s a growing need for Fit and Forget. The Luma is now finally making that possible.”