Here we’re focusing on light fittings which are used for residential roads, as opposed to other locations such as traffic routes, town centres, main roads, freeways and motorways.
In the European standard, EN13201, these residential roads are classified as P Class (P for pedestrian). The IES North American standard RP-8-14 has different classifications and the fixtures here would mainly be used for what are called ‘local’ roads in the US.
However, the standards are similar in that they both place the emphasis on horizontal and vertical illumination. The vertical illumination helps you recognise people’s faces. The horizontal illumination means you can clearly see objects when you approach them from any direction.
This compares with traffic route lighting where more emphasis is placed on the brightness (luminance) of the road surface and what can be seen directly in front of the driver.
The lighting recommendations in the standards are based on many factors such as traffic volume, the interaction and potential conflict of vehicles with pedestrians, the amount of parked cars, crime rate and whether it’s an urban or rural location.
Typically, average horizontal illumination values are 2 to 15 lux and minimum vertical values at face height are 0.6 to 10 lux. Uniformity is also important: shadows can make obstacles harder to see or they can be confusing for people with poor vision.
These engineering criteria are often quite strict. Furthermore, manufacturers offer a wide range of optical distributions, so you might want to use a professional street lighting designer to ensure your scheme complies.
It’s worth remembering that streetlights are rarely replaced (compared with, say, retail fixtures) and may have to last 30 years or more. For this reason, future proofing is especially important.
‘Smart cities’ is an unstoppable trend and you most probably will want to add controls and sensors (temperature, movement, illumination level etc) at a later date.
Make sure your lantern has good connectivity and is easily upgradeable. Examples are the ANSI 7-pin NEMA socket and the Zhaga System Ready, SR, socket.
Finally, remember that overall power consumption is always important. A few less Watts/Volt-Amps per lantern means big cost savings over the life of the installation. The total cost of ownership should be your guiding principle.
With a heritage extending back to 1923, CU Phosco has a long pedigree in streetlighting. This is an elegant looking streetlight. It’s narrow and with flowing curves rather than sharp angles. I particularly like the slightly tapered head of the lantern which is only 120mm (<5”) wide. There are two versions and light output ranges from 730 lumens to 4,250 lm.
You can see from its construction that a lot of effort has gone into the thermal management and this is reflected in the maximum operating temperature of 40C which is higher than many lanterns.
The driver is compatible with most central management systems (CMS) and there is an option of mini photocell and 7-pin NEMA socket. All in all, the P852K is a thoroughly well designed lantern.
If you’re looking for something that looks different, the Sephora is your answer. Basically, the lantern is disk shaped. It can be supplied either as a halo shape or central circle. These can be combined or stand-alone. For residential applications, you can have a halo of light (650mm, 26” in diameter) emitting anything from 1,000 to 18,000 lumens. Alternatively, you could have the circular centre of the halo (450mm, 18”), giving the same amount of light.
The sides of the Sephora can also be chamfered so it looks like an Olympic discus. There is a choice of either Comfort (for good vertical illumination) or Performance optics, five beam shapes and the lantern can be fixed with a side or bottom mount. There’s a trend for warmer light sources to be used in residential areas and the Sephora Comfort version is available in 2200K as well as 2700 and 3000K. The Performance version also offers 4000K.
The S-Line is specifically designed for residential roads and has a lumen output range of 1,000 to 4,000 lm, 13 to 34W. It weighs just 4kg (9 lbs) and is only 66mm (2.5”) deep. Where you want greater illumination, there is the larger R-Line which ranges from 5,000 lm and 32W up to 17,000 lm and 133W. The S-Line is smaller than many of the other streetlights.
It’s a nice, unobtrusive lantern. There is the option of a 4mm-thick tempered glass cover or a polycarbonate lens which gives it an IK10 impact resistance – useful in some residential areas! A perceived disadvantage of this lantern, although maybe not in practice, is the limited range of beam distributions. It can have a NEMA 7-pin socket and is also available with DALI control gear or pre-set dimming levels.
Streetlights have to last a long time, under all weather conditions, so it’s reassuring to know that both the managing director and technical director of Indo have a masters degree in engineering! They understand what’s required from a streetlighting lantern. The main feature that distinguishes the AIR1 from the other manufacturers is that it doesn’t have an LED driver. Many people consider that the driver, especially the wet electrolytic capacitor inside, is the component most likely to fail in an LED fixture.
This, therefore, can have a significant effect on the life of the installation. Not having a driver also means the fixture can be smaller. Being able to dim streetlights is a crucial aspect for saving energy and a criticism often made of driverless LED fixtures is that they cannot be dimmed. The Indo technical data sheet states that the AIR1 can be dimmed to 50 per cent but this is conservative. In fact, for most installations it will dim down to just 25 per cent. E.g. 40W to 10W. It also has a constant light output function which is becoming a common requirement of streetlighting projects nowadays.
Another neat feature is the option of an integrated solid state photocell. Unusually, this faces downwards. It can be pre-set or programmed to different lighting levels. E.g 50 per cent output after midnight.
This lantern has been particularly designed to keep the LED chips and driver as cool as possible. The Arialed Mini will operate at an ambient of 50C (120F). Orangetek has accomplished this in a rather unusual way in that the cooling fins are upside down and air passes around them through multiple slots in the body of the lantern. This arrangement also has the advantage that dust or leaves cannot accumulate in the gaps between the fins. Thus the upper face of the lantern is smooth. It has also been designed with the so-called ‘circular economy’ in mind. The individual components, such as driver and LED module, are easily replaceable and upgradeable whereas the aluminium body may last 40 years.
The lumen output ranges from 1,250 to 9,200 lm with a limited range of four standard light distributions but the company offers a bespoke lens development service for special applications. Bearing in mind its residential use, it’s good to see that Orangetek offer side and rear baffles.
The DigiStreet range, from its initial concept, has been specifically designed to be inter-connected and upgradeable. There's a complete family from the Mini with just 10 LEDs to the Large with 120. There’s also a choice of 20 optical distributions so you could most probably illuminate a whole new city using just the DigiStreet. For residential applications, we looked at the Micro which has either ten LEDs (8 to 21W) or 20 LEDs (19 to 41W).
This gives a range of 1,200 lumens to 6,000 lm, more than enough for this type of application. A useful feature is the service tag on the lantern. This QR code label enables you instantly identify the configuration of the driver and optics and includes installation and diagnostic information. The DigiStreet is supremely upgradeable; everything about it is designed to be future proof. For example, all the major components can easily be replaced.
Of course, as this is Philips, the luminaires are built to be connected to the well-established Interact City Touch lighting management system where you can measure, monitor and manage the complete lighting installation.
Thorn has been manufacturing luminaires for 90 years and they are one of the reliable, go-to companies whenever you think of streetlighting. There are several residential lanterns from Thorn but I’ve chosen the Flow because it looks different from many of the others. The name Flow refers to both its shape but also the way people and traffic move through urban areas. It is available with a warm 2700K light source with a colour rendering index (CRI) of >80 which makes it an ideal choice for residential areas and urban centres. Other colour temperature options are 3000 and 4000K.
There’s a choice of 14 optical distributions and the light output ranges from 1,700 to 13,600 lumens. It’s designed to be compatible with all radio frequency systems on the market and there are other options such as Dali, bi-power, power-line and Zumtobel Group Services’s own lighting control system, InCity.
You can immediately see that this has been designed by someone who understands the requirements for a streetlight. The fins on the top are open at one end so that rain and dust cannot collect in the channels. The glass over the LEDs is contoured so that the light passes straight through rather than some of it being lost through internal reflection, which can be the case with a flat glass.
WE-EF designs its lenses in-house and it uses the layered illumination approach so that if one LED fails, rather than produce a darker area on the road, the illumination level is just slightly reduced. There are six beam distributions and none emits any upward light. The body is powder-coated marine-grade aluminium; the stainless steel fixings are polymer coated and the whole unit is factory sealed so it doesn’t need to be opened during installation. The model we looked at is the 520 and is the smallest at just 14W which delivers 1,600 lumens.
There are more powerful versions of this unit giving 5,400 lm. Ultimately, the VFL500 series goes all the way to 144W.
- Top streetlight manufacturers, including CU Phosco, DW Windsor, Pudsey Diamond, WE-EF, Acrospire and LEDvance will be unveiling their latest products at LuxLive 2018. The show takes place on Wednesday 14 November and Thursday 15 November 2018 at ExCeL London. See the full programme and register free HERE.