How the colour of your racking can cut your energy costs
Graeme Shaw, Technical Application Manager at Zumtobel Lighting looks at the relationship between light, colour and energy resource within a data centre application and the direct impact this can have on reducing energy consumption in Data Centres.
For data centre operators, energy efficiency is the primary objective, as any specifier working on a mission critical facility knows to be true. But what if you knew another way to optimise the efficiency of your facility and cut your costs without purchasing more products? After all, any positive impact on your PUE must be a good thing, right? Well, those extra savings may just be found in a place where you least suspect. In fact, the colour of racking has a direct impact on a data centre’s lighting energy consumption and, ultimately, the operator’s bottom line.
Good lighting quality is required for a variety of reasons, but perhaps the most critical reason is to enable technicians to read data displays and legends on equipment in order to make accurate observations and changes. When light shines on a black surface, the colour appears saturated and absorbs more lumens. White, on the other hand, has a significantly higher reflectance value, meaning more light is distributed throughout the space and, crucially, requires a lower lumen package to achieve the TIA recommended lux levels for data centres.
Black is the most common finish for IT equipment in data halls but, unfortunately, this colour actually works against producing an optimised lighting design within a data hall. This is because, to overcome the inefficient light reflectance of a black surface, the only solution is to use more light fittings, which in turn, leads to a higher capital and operating cost.
The solution
Development and operating costs can be reduced during project design stage if the colour of IT equipment/racking is specified as white rather than defaulting to the industry standard, black. This would represent a 37% reduction in the number of luminaires required at initial install coupled with a 37% lifetime reduction in the lighting system power usage.
Model 1- black IT equipment
| Equipment Reflectance | Av. Horizontal Illuminance | Av. Vertical Illuminance | Power per m² | Qty of luminaires |
| 4% black | 506 lux 0.6 Uniformity | 232 lux @ 0.33 Uniformity | 4.31 | 104/ 562m² |
Model 2- white IT equipment
| Equipment Reflectance | Av. Horizontal Illuminance | Av. Vertical Illuminance | Power per m² | Qty of luminaires | |
| 85% white | 1009 lux / 0.63 uniformity | 718 lux / 0.45 uniformity | 4.31 | 104/ 562 m² |
Conclusions
| Model | Equipment Reflectance | Av. Horizontal Illuminance | Av. Vertical Illuminance | Power per m² | Qty of luminaires |
| 1 | 4% black | 506 lux @ 0.6 uniformity | 232 lux @ 0.33 uniformity | 4.31 | 104/ 562 m² |
| 2 | 85% white | 600 lux @ 0.45 uniformity | 418 lux @ 0.44 uniformity | 2.7 | 65/ 562 m² |
The luminaires used in the modelling scenarios above are from the Zumtobel Tecton C range with 4000k LED & split optic technology, supporting enhanced illumination on vertical surfaces
Conclusion
If you were designing the interior of a data centre and chose to opt for white racking instead of black, the number of luminaires required could be reduced by up to as much as 37%. Additionally, there would potentially be another 37% of savings realised in the energy used for lighting. So not only do you save at the design stage where you need less light fittings to achieve the same lux levels, but you also save the energy which those luminaires would have consumed throughout their lifecycle. That’s a lot of savings in both the short and long term.
As a lighting manufacturer which has supplied to many data centres, we are inevitably asked the question, ‘why do I need so many luminaires?’ and that’s when we begin the racking colour conversation. Imagine if the walls of your home were painted black. Even with identical sources of natural and artificial light, it’s the same principle. You require more luminaires to achieve the same levels of light.
Lighting may only consume a fraction of the total energy used within a data centre but its impact and cost savings go far beyond the cost of the lighting. In addition to saving energy and reducing costs, an efficient lighting system can offer data centre operators a solution to, minimise maintenance and maximise safety.
Zumtobel UK Details
Tel: 01388 420042 Email: Email: info.uk@zumtobelgroup.com Web: https://z.lighting/en/zumtobel/
UK Media
Emma Cronin
Marketing Communications & Events Coordinator
Phone +44 (0) 7785 248642
https://z.lighting/en/zumtobel/
About Zumtobel
We are passionate about designing and producing the highest quality of light. Our work is driven by the knowledge that the right light can create the right environment for people to thrive when tailored to their individual needs. Guided by a unique design approach, we continuously push our boundaries in search for perfection through unique and timeless design. As we develop the next generation of lighting, we build on our family heritage to refine the aesthetics of light and shape the lighting of tomorrow. With a special blend of passion, grace and avant-garde ideas, we turn light in to an experience and remain committed to the goal of improving the quality of life through light. Zumtobel is a brand of the Zumtobel Group AG with its headquarters in Dornbirn, Vorarlberg (Austria).
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