Electrical Contracting News (ECN) October 2016 - Page 51

LIGHTING I n commercial and industrial buildings, lighting typically accounts for around 20 per cent of total electricity usage and in some cases the figure can be as high as 50 per cent. It is therefore hardly surprising that lighting is a prime target for efficiency savings. It is not only a key factor in the design of new buildings but a popular retrofit option for facilities striving to reduce their energy consumption. Where lighting systems are 15 to 20 years old, the adoption of newer technology can bring the running cost of lights down by 50 per cent or more. It’s an appealing proposition. However, the appetite for energy savings should not be allowed to overshadow the need for a holistic appraisal of lighting requirements in a large industrial or commercial building and a thorough understanding of the expenditure involved. Therefore, it is vital to answer a number of key questions that will help ensure that any upgrade or replacement of a lighting system delivers not only an efficient but an effective outcome. 1. What is the space used for? It is surprising how regularly this simple but vital consideration is overlooked. Establishing an answer to this question is an important starting point for any SPECIAL FEATURE Consideration should also be given to the occupants of the building. prospective installation. Lighting must be designed to assist occupants in whatever task they are undertaking. In some manufacturing environments, for example, it is vital that workers are able to identify subtle differences in the colour of materials. If the light offers poor colour rendering, as may be the case with the yellow tinge of an older high pressure sodium installation, it could inhibit that task. Instead, a more modern light source with good colour rendering is crucial. Another factor that typically influences the quality of light in a building is the extent to which replacement lamps have been mixed and matched over the preceding years. 2. What is the effect of lighting on building occupants? Consideration should also be given to the occupants of the building. Poor lighting will have a detrimental effect on an individual’s ability to perform tasks. Evidence also strongly suggests that it can contribute to depression (especially in the winter months) and can even lower productivity. On the plus side, appropriate and suitable lighting has many positive benefits, particularly where employees are fully engaged in the process. According to the HSE, studies have shown that giving workers in open plan offices control of lighting can increase job satisfaction and, at the same time, decrease stress. Indeed, a growing body of research underlines this important link between lighting and wellbeing. Lighting for People, a research paper that was produced as part of the European Union’s programme for research and technological development, has drawn together a wealth of research to demonstrate just how important