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Lighting in the retail and leisure sectors has two fundamental functions; apart from the basic requirement to provide illumination, it must make products and services look more appealing to customers. Indeed, display and specialist lighting for hotels, health clubs, shops and particularly supermarkets is fundamental to the success of those operations. Studies show good lighting creates a positive ambiance that will result in more sales This relationship between the practical and the aesthetic is fundamental to the success of any lighting design.

1. Energy issues

Supermarkets and large shops are reconsidering the use of daylight in a move to reduce energy bills and improve their environmental profile. This move away from large areas of energy-intensive lighting creates the need to focus on more sophisticated ways of achieving an attractive result.

Additionally, the new Part L imposes greater constraints on display lighting than the 2002 version. It requires lighting to have an initial efficacy of no less than 15 lamp-lumens per circuit-watt, including any transformer or ballasts. Additionally display lighting must be capable of being switched off when not required and less intense forms of lighting should be used for safety or cleaning activities. As energy prices increase this will become an increasingly significant issue for building operators.

2. Technologies

Luckily new technology is on hand to help the specifier meet the requirements of the regulations. The use of LEDs, compact fluorescents, fibre-optics and better controls can go a long way to delivering exciting and energy-efficient displays.

LEDs, for example, are becoming more powerful and are available in many colours including bright white. They offer very long life - some say they will outlive the building they are in. Several manufacturers offer fittings consisting of clusters of LEDs, which can be used as an alternative to energy-intensive and heat-emitting metal halide lamps.

In contrast, LEDs are very cool running and enable light to come from many point sources; these can be linked together to create lines or shapes.

LEDs are also available pre-mounted in strips to give evenly distributed illumination in flooring or wall panels. Units can also edge-light glass or perspex, delivering a constant or changing colour.

Fibre-optic lighting can deliver a range of effects.

The fibres can be woven into mats, carpets and curtains or built into fixtures and fittings. Fibre-optics can also be used where temperature can be an issue, such as with food displays. Due to their long life they can also be permanently built-in.

Fibre-optics can be used in wet areas or in inaccessible details as the lamp can be located some distance from the ends of the fibres. One light source can feed a large number of fibre optic bundles, delivering light in a pattern or distributed evenly. These can create colour effects and have a built-in filter system.

Small fluorescent tubes smaller than a pencil - typically 8 mm in diameter - are available. These are a strong source of light and are useful to illuminate small spaces such as display cases, or for more general illumination where they can be hidden within an edge detail.

3. Safety lighting

Some of these technologies can also be used for safety applications.

Escape routes require a minimum level of illumination as set out in BS 5266. Additionally, the clear definition of building elements, as required by disability regulations, can conflict with design aspirations. The balance for the designer is to ensure both aspects are covered.

Lighting in stairs and circulation must be modelled around the stair geometry. LEDs built into stair nosings, handrails and edges can create dramatic effects and ensure the safety of users.

4. Practical issues

All equipment must be capable of being safely maintained. This can be difficult owing to a number of factors. Consider the location and the manner in which the bulb would need to be replaced. High-level lighting can prove costly and difficult to maintain - closing a significant area of any commercial premises is normally not an option.

Consider using long-life LEDs or fittings that can be lowered to change bulbs. Many businesses change bulbs on a programmed schedule although this can be wasteful of resources.

Remote sources using fibre-optics reduce the need to disrupt displays. To reduce their lighting load, supermarkets and some large shops are considering the reintroduction of roof lights to save energy.

If in doubt, a risk assessment needs to be drawn up to identify the issues and help define a safe solution.

Control systems are becoming more sophisticated - the use of wireless or control signals sent through the main electrical wiring make the control of individual fittings easier and more cost effective. Controls can also save energy by reducing or switching off unwanted fittings to a pre-programmed sequence or in response to a range of parameters.

5. Key points

Consider the technologies from several aspects, not just aesthetics:

• Many small sources of light are often much better that a single, big-bang approach
• Energy conservation is climbing up the agenda, especially with clients
• New regulations should be seen as a design opportunity.
• Specialist help should always be considered at the detailed design stage.