Over recent months I’m sure you have seen a number of calls in the media for firms not to neglect their environmental objectives as a result of the uncertainty in the economy. These calls have come from a wide range of sources and especially from professionals working in our sector – the built environment.
Welcome though these calls are, it often seems that these sentiments ignore a very important principle; namely, that environmental friendliness and cost savings are not mutually exclusive. In fact, saving energy and saving money are often the same thing.
Some things never change, though. The ongoing and underlying problem with lighting in far too many of our buildings is that their lighting schemes work to a lowest common denominator, providing what is good enough rather than what is best on a number of different levels.
For example, while providing 400 lux throughout an office might provide you with a good basic level of light at a relatively low cost, it may also be counter-productive in a number of ways – not
least in terms of environmental impact, where calculations based on return on investment should overwhelm considerations of purchasing costs.
The problem can be systemic. As a facilities manager, you’ll have heard this argument many times about all aspects of buildings, but too often, decisions about lighting design are left too late in the design process. So, when and if the budget becomes tight, this can lead buyers to focus on accepting something that may not be right for them or the environment. Cost – and specifically initial purchase cost – then becomes the most significant factor. This is what lies behind the popularity of the fluorescent tube, which is at the very least a cheap and effective solution.
Green guidance
One of the most important developments in this area in recent years has been linked to the much-publicised 2006 Building Regulations, which set certain duties and standards with regard to energy efficiency. However, there is scope to develop schemes that easily exceed the requirements of the regulations and already the DFES issues guidance that goes well beyond them for new and refurbished schools.
The capacity to exceed the minimum requirements is not just limited to schools, of course. The choice of lamps, luminaires and control gear will determine results, so it is extremely worthwhile getting professional advice for individual schemes, the complexity of which is beyond the scope of this short guide.
A good first port of call for extended guidance is CIBSE, although it is also wise to consider relevant standards such as EN 15193-1 (energy performance of buildings, energy requirements for lighting part 1: lighting energy estimation) or EN 15251 (indoor environmental criteria for design and calculation of energy performance of buildings).
When it comes to making decisions about the installation, the good news is that a well designed and managed lighting scheme will be beneficial not only for the environment but also for the balance sheet. These two important objectives are often intertwined in many aspects of the debate about the environmental impact of commercial buildings, and this is particularly true of lighting schemes.
Simple decisions about light fittings and building controls can have an enormous impact. For example, by specifying eco-tubes – which have a different internal pressure from standard fluorescent tubes – you can expect to save around 10 per cent of your energy costs in a typical installation. A simple notepad calculation based around a typical life expectancy for the fitting of 20,000 hours reveals that installation of eco-tubes for most users
will pay back the initial installation costs within four years.
You can go one step further. Reflex eco-tubes direct more light downwards so provide around 50 per cent more useful light per tube; this means that specified well, they can save installation costs and about one-third of running costs.
Similarly, never assume that all areas within an office require the same specification. Obviously, the provision of natural light should influence decisions, but it is also worth bearing in mind that different types of work require different types and levels of light. As the recent refurbishment by Claremont of Leeds BuildingSociety’s HQ illustrates, many modern offices have different areas for computer work, meetings, break-out space, relaxation areas and so on. Intelligent decisions taken on this basis can have a significant bearing on energy costs.
It may also be worth bearing in mind that return on investment does not just refer to physical hardware but also human capital. A well-lit interior, preferably with lots of daylight, can result in significantly higher productivity and significantly lower levels of illness and absenteeism.
Easily the most talked-about technological development in lighting design over recent years has been LED lighting. Many of its proponents argue that it is ecologically superior to other types of light fittings, and in some ways they are right. Certainly the fact that mercury is absent from the manufacture of LED fittings is positive, but in most cases LED is not yet up to the efficiency of fluorescent and other traditional high-energy fittings will almost invariably perform better than LEDS.
That should change over time, but the rule of thumb for now is that while LED may be a welcome part of an environmentally-friendly lighting scheme, we should keep an open mind when it comes to any specific project.
Of course, some solutions are technical and some are not. The management of light fittings, for example, is just as important as the hardware itself. At the most obvious yet all too often neglected level, we should use as much natural light as possible and remember to turn the lights off when they’re not in use.
Products exist that help to manage these important factors. For example, motion sensors will turn off lights when they are not needed, and daylight compensation controllers can automatically vary light levels depending on the availability of daylight in different parts of the office.
Any such scheme should also bear in mind the differing needs of individuals. Some people are mushrooms, requiring very little light to function, while others only seem to flourish under bright lights. Photocells are available which can provide a degree of personal control, but in many cases the only solution is a bit of give and take from everybody. Most organisations work well on this grown-up basis.
Cost, cleaning, maintenance and asset management are all big factors, and you should also look at issues such as whole-life costing and performance. For example, you can specify to a certain lux level, but through usage lamps can reduce in their performance, especially if they are of inferior quality. You must also take care that specifications are not so complex that you need to stock 35 types of lamp.
The road to environmentally-friendly lighting does not depend on good intentions alone. There is a strong business case to be made for effective schemes, and enlightened management will look
at whole-life costs, not just initial installation costs.
Further information
Mike Lear is product manager – lighting, HVAC & pipe systems, RS Components, www.rswww.com
General guidance on lighting in different types of buildings is available from the Society of Light and Lighting, a part of CIBSE www.cibse.org
www.claremontgi.com