How many ways can you light under a shelf? Well, there are quite a few actually.
Maybe because I don’t like shopping, it never occurred to me that the biggest market for under-shelf lighting is retail. I spoke to one multi-million turnover company and all they make is under-shelf lighting. That’s it.
The buzz phrase is RDL, which refers to retail display lighting – or refrigerated display lighting, depending who you ask. It’s cool either way!
We looked at lots of clever technology this month, ranging from products incorporating royal blue LEDs to ones with electrically conductive composite materials.
As always when deciding what luminaire to buy, you need to think about the function and appearance of the lighting. Do you want a continuous line of light or single points? Do you want the lighting effect to have lots of sparkle or be uniform and shadow free? Colour rendering is obviously important for retail applications but may not be for other commercial uses.
Mounted or recessed?
Surface mounting luminaires is easier but they can be visible unless set a long way back. Recessing them means the shelf has to be thicker. In either case, when shelving extends the full height of the wall, most but not all, light sources can be seen.
There is a huge range of luminaire types, so it’s better to look for the particular features you want. Also, most manufacturers offer a range of products for under-shelf lighting and we have had to choose just one product to review. I could have filled this article with products from just one manufacturer!
The main criteria we’ve looked at are lighting quality, product range and construction.
8point3 LED Sabre Architectural
This luminaire caught my eye because you can change the CCT simply by swapping the diffuser. In fact, it’s a lot more sophisticated than that. Light is produced by 455nm royal blue LEDs which excite the phosphor on the underside of the polycarbonate diffuser. It’s the ultimate in remote phosphor technology. The benefit is that the phosphor runs very cool and has a totally uniform appearance along its length and around the 260° beam. Best of all, if you want to change the CCT, you just swap one diffuser for another. It is also an extremely efficient way of producing white light: the 4000K version emits over 100lm/W with a CRI of over 80. The 2700K version has a CRI of 90. The Sabre can be made in bespoke lengths from 300mm to 5m. It can be driven over a wide range of power ratings to achieve between 600 lm to 4,000 lm per linear metre. You could even use it in cove lighting and still be Part L compliant.
Aurora CB104 Cabinet Light
This is a simple, budget range 500mm light bar from Aurora, one of the biggest manufacturers there is. It is surface mounted and is 20mm wide x 14mm high. You can connect the bars together continuously up to 5m. The transformer is remote. The 550mm long 3000K light bar is rated at 8W and emits 338 lm (the colour-rendering index isn’t quoted in their datasheet and wasn’t available as we went to press). It may not be the most exciting looking under-shelf lighting unit, but it is keenly priced, does the job and will most probably sell by the shedload.
This is completely different from any of the other luminaires in this review. In essence, it is a complete shelving system, just 4mm thick, which has integrated LED panels. It doesn’t fit neatly into any category of luminaire but shelf display is probably closest. The technology is in the composite material which comprises two layers of aluminium with a plastic insulation layer in between. A remote power supply feeds 24v to the edges of the aluminium. Light is emitted from a square array of LEDs embedded in the composite material. The 10W lighting array we tested is 80mm x 80mm and the standard 2800K version emits 964 lm with a CRI of 85. Other versions are available rated at 5w and 10W. CCTs of 4000K and 5000K are an option. An extra feature is that since the supporting frame can act as a busbar, individual shelves can be repositioned, added or replaced without any rewiring.
iGuzzini has a huge range of products under the Underscore name; I counted 16 different recessed and surface profiles. The range is designed as much for aesthetic architectural applications as functional lighting. The diffuser on the Underscore 6 is just 6mm wide and is intended for use where you want a long, ultra-slim line of continuous light. For more functional lighting, you can obtain much greater light output with the Underscore 15. Various power ratings are available, but you can achieve 1350 lm at 20W per linear metre for the highest power unit. If you want colour changing, there is the Underscore 18 which has RGB LEDs. For stylish shelf lighting, go for the Underscore 15. Suffice to say that if you want a continuous line of light, you’ll be able to produce it with Underscore. As their literature say, you can illuminate or decorate.
KKDC Tana SP
KKDC are much loved by lighting designers for the wide range of colour temperatures, colour consistency and high CRI. The Tana SP (16mmx 16mm, by no means the smallest available) is the latest addition to the range. A neat feature of all the KKDC luminaires is that the aluminium extrusion has a ‘return’ underneath which conceals a direct view of the light source. Most LEDs are also angled at 45° so that more light is directed rearwards into the shelf space. The model we tested has a totally homogeneous diffuser and closely spaced LEDs so you achieve a very uniform line of light. Coupled with the concealed snap-in mounting clips and hidden through-wiring, you can achieve long, continuous runs of light.
Lumenal have a range of linear LED systems, designed and manufactured here in the UK. The triangular (approx 30mm on the short sides) shaped Velorum has been specifically designed to fit the slotted steel shelf units used in supermarkets and retail gondolas. Typically, the Velorum would replace 21W T5 fluorescent units although it can be made to custom lengths to suit the particular widths of the shelving. There is a choice of clear, semi or fully frosted or coloured lenses and diffusers. The gear is remote and various output drivers can be used to achieve either the maximum light output or the lowest power consumption.
Osram Slim Shape LED 1
This surface-mounted luminaire really is slim. It is curved in section and is only 12mm at its deepest point. The ribbed aluminium sides and opal diffuser make it ‘disappear’ even more. However, to achieve this shallow appearance, the gear has to be remote and is supplied with two 1.5m flying leads. It’s an attractive looking unit and it even has a tiny (6mm x 6mm) on/off button on the end. You would choose this luminaire in locations where it is likely to be seen. The 3000K LEDs inside would also suit this market but the CRI is a bit lower than you might expect at 75. The 13W unit which is 400mm long emits 680 lm and there is an 8w version at 420 lm. Osram also makes a beefier under-shelf unit with integral gear and asymmetric light distribution called the LDV Linear.
PJR Engineering Mini Remote T2
PJR Engineering are a well-established UK company who not only have their own range of fluorescent luminaires but have been making ‘specials’ for designers and consultants for years. You have most probably seen their luminaires in an award-winning scheme and not been aware of it. We chose the T2 batten unit with remote ballast simply because it is so small for a fluorescent luminaire, being just 20mm x 20mm in section. PJR also make a slightly larger one with integral gear. Obviously, the length varies with the wattage of the T2 lamp, but an 11W unit is about 425mm and a warm white emits 620 lm with a CRI of 80-90. Why T2? People have been prophesying the demise of the T2 for decades, but the reason for choosing it is that the technology is so well established. Also, unlike almost all LED luminaires, you can replace the light source at the end of its life.
This is another complete system designed for under-shelf lighting and is aimed squarely at T5 applications, but with more flexibility. The aluminium section is quite small, 12mm x 22m and it can be built up from module lengths as small as 140mm or in multiple sections within an extrusion. These modules can then be connected in a variety of ways and spacings using plug and play cables. Typically, the system emits 680 lm per linear metre, with a CRI of 80-90. Although the InteGrade can suit most retail applications, there is a lot of emphasis in the Philips literature about use in chiller cabinets and refrigerated displays. An interesting feature of the InteGrade, not found on many other systems, is the rotational mounting bracket allowing for 15° steps.