New lighting will pay back its costs in just over two years
New lighting and controls in the headquarters of the South East England Development Agency will repay its investment in just over two years through energy savings.
‘We asked ABS Consulting to recommend what practical and most efficient measures we could take to cut our excessive energy use which would give use the greatest return on investment. Eliminating wasteful use of lighting by automatic lighting management was the clear winner,’ says Fiona Crann, head of facility at the South East England Development Agency’s (SEEDA) 5-storey headquarters building in Guildford. To put that recommendation into practice, an Ex-Or MLS digital managed lighting system has been installed throughout the building to eliminate the unnecessary use of office lighting. The scheme has helped SEEDA meet its ISO 14001 environmental responsibilities and cut electricity consumption by up to 15% — representing an annual energy cost saving of £7000 to £9000 and paying back the capital cost in just over two years. The previous luminaires were installed when the building was first constructed in 1989, and the 600 to 650 lx they delivered was much higher than actually required. ABS recommended that efficient lighting control and more up-to-date fittings should reduce the illuminance to 400 lx. In addition, lighting control would ensure that lights came on only at times when they are needed. ABS specified Ex-Or for the lighting controls on the basis of excellent results with previous projects. Electrical contractor Edmund Services carried out the work over six weeks and out of hours to minimise disruption. Existing recessed LG2 Cat 2 fittings with two 36 W lamps were replaced by T5 ALD Lighting Fusion luminaires with four 14 W lamps and the Ex-Or MLS digital managed lighting system throughout the building. The Ex-Or system ensures that lights remain on only when needed and automatically ensures that light is delivered at optimum levels. Detectors share information on occupancy and light levels to provide lighting tailored to the needs of occupants, in conveniently configured work zones. The system detects the presence of occupants and measured ambient light to regulate luminaire output. It also ensure that lights in key circulation areas are kept on. Staff in some areas of the building have hand-held remote control devices to control their light levels for particular types of work. Luminaires revert to the original settings when individual control is no longer required. Fiona Crann says, ‘The difference is incredible. Dimming and switching of the lights is indiscernible. No longer do the lights blaze endlessly and needlessly outside office hours just because people have forgotten to switch them off. But most interesting of all, by involving the staff in these changes and demonstrating our commitment to energy savings and sustainability, they are now finding other ways themselves of saving energy — for example, by checking their IT equipment and monitors are switched off when they have finished using them. ‘Before-and-after metering measurements were taken in the first wing to be converted, and they showed an immediate cut in electricity use of 20%. Because each wing has different levels of natural light, we expect to achieve a building-wide saving of up to 15%. This will give us a payback of just over two years — a creditable return on investment indeed.’
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