Nowadays lighting operation costs becomes more and more significant to a company. Historically, high-intensity discharge lamps have been the light sources of choice for warehouses. Here is a case study for demonstrating that fluorescents can replace HID high bays in storage applications from LUX Magazine.
Riegens Lighting was given the unenviable task of relighting a warehouse with alternative sources throughout, with the goal of cutting energy use. The refurbishment of The Retail Supply Group (RSG) warehouse at Coleshill in the West Midlands gave Riegens a chance to show that T5 fluorescent tubes can be a cost-effective alternative to HID.
Mark Streeter, Riegens’ senior project engineer, told Lux: ‘RSG proves that a switch to fluorescent lighting can be a cost-effective alternative to HID luminaires for high bay applications in warehouses.’
RSG encompasses Glopac, an established UK packaging supplier, and Greenpac, an ‘eco-friendly’ packaging and textiles firm. It was essential for a company with such well-defined green credentials to behave in an environmentally responsible way.
No Re Wired Needed
Riegens set out to design a lighting scheme for the warehouse that would not only reduce energy consumption but also meet Cibse guidelines. The aim from the start was to use the same number of luminaires as the previous scheme.
The original fittings were installed only three years ago and the client did not want to incur any rewiring costs.
Riegens’ tests demonstrated that replacing the existing 400W metal halide lamps with Riegens HB-ECO 4 x 54W fluorescents – with 4000K tubes – would save signficant amounts of energy.
HB fittings are part of Riegens’ power-saving ECO range. They can be surface mounted or suspended, and can be controlled by signals from sensors to minimise running costs.
HB-ECO fittings are available in two or four-lamp options, with a choice of 40, 50 or 80W PLL lamps for large open areas.
HB-ECO’s asymmetric reflectors are designed to optimise light distribution.
All Riegens’ tests were checked and veryfied by an M&E consultant from the Carbon Trust, which provided an interest-free loan to finance the project.
The figures showed a saving of £17,170 a year on energy bills and 85.1 tonnes of carbon dioxide, based on the Carbon Trust’s criteria.
Streeter says: ‘These savings were on a point-for-point replacement basis, and did not include the contribution from the passive infrared sensors mounted to every fitting. Because the warehouse has plenty of daylight and has minimal use I would estimate a further 50 per cent energy savings.’
All fittings were equipped with an built-in presence and daylight sensor from Ex-Or and Dali control gear. The sensors were commissioned on site to the ensure adequate lighting.
Streeter says the Carbon Trust consultant’s checks ‘gave the client confidence to believe the savings’.
He adds: ‘If the Carbon Trust veryfication hadn’t been in place, the main problem would have been to convince the client of the saving because they have no electrical engineering knowledge. This I think is true with many end users we deal with.’
Greenpac director Liam Knowles says: ‘We are delighted with the signficant increase in light levels, coupled with immediate energy savings achieved through this replacement system – which is fully inline with and reinforces Greenpac’s philosophy.’
‘By taking advantage of The Carbon Trust government grant, we have identi ed signficant projected energy savings, providing an anticipated payback calculation of up to three years maximum.’