5 Applications and Techniques
5.1 General Considerations
The application of the right light is paramount in lighting design. The simple golden rule for design considerations is to provide the right light to the right place at the right time. This rule is valid for all places where lighting for people is needed so that they can see and perform the visual tasks efficiently and in comfort. The specific lighting requirements of people and places vary according to the type of place, activity and people involved. The visual tasks can differ in character, location, size, colour, duration, dynamics and ergonomics. It is very important to assess these parameters and to formulate the right design objectives for the specific lighting application area. Once the task analyses have been completed and listed the required lighting design criteria can be selected and the lighting design process can start. See also the list of recommendations within the appropriate lighting application standards referenced in this book.
This section of the handbook gives an insight to the activities and visual tasks found in the various lighting application segments and gives advise on the important points to consider.
It recommends the most appropriate lighting design techniques and suitable lighting solutions. The list of application segments is not exhaustive but the main types covered include the lighting of indoor and outdoor industry, offices, education buildings, super and hypermarkets, roads, amenity areas, architectural elements and healthcare premises. For each case the lighting techniques employed should start by considering a holistic approach to design and should include PEC – performance, efficiency and comfort - attributes and fulfilment. This means addressing all the lighting design parameters and balancing the requirements and constraints to yield the best possible solution.
In the holistic framework the key elements for consideration are visual function, visual amenity, architectural integration, energy efficiency, installation costs and maintenance. The individual elements may not carry equal weight, but they
all need consideration separately and combined with each other. PEC extends this consideration to include the changing human factors and environmental challenges. By fulfilling PEC we ensure that quality lighting will be provided that gives effective light for visual performance, with high operating energy efficiency, be sustainable and kind to the environment, and give people comfort, stimulation and total satisfaction. It is well proven that good lighting is essential to mankind, without this the human activity will be seriously impaired and valuable energy and resource will be wasted. It is also important to recognise that this lighting not only illuminates the task but will also contribute to the quality of the visual environment and wellbeing of the people.
Much of the success of a lighting installation depends on making the right decisions at the design stage, selecting the right equipment and providing adequate instructions on how to operate, manage and service the scheme through it’s life.
In the section “Specific Techniques” guidance is given on techniques that are applicable to several application segments.
These include, lighting for display screen equipment, lighting for education, emergency lighting, road and amenity lighting, controlling obtrusive light, lighting for crime prevention, lighting for health, lighting controls, lighting maintenance and tunnel lighting. The consideration of these form an integral part of the design process to yield the most appropriate lighting solution.
Healthcare Section 5.6
Urban – decorative roadlighting &
amenity areas Section 5.9
Education Section 5.3
Sports lighting Section 5.11
Office Section 5.2
Super/
Hypermarket Section 5.7
Road lighting Section 5.8
Urban – architectural floodlighting Section 5.10
Industry – indoor Section 5.4 Industry – outdoor Section 5.5
Fig. 5.1 City plan showing the diversity of lighting needs. This section gives hints on lighting techniques for each of these application areas, helping the reader to tackle such everyday projects with greater understanding.
Techniques
General
Office lighting is a general term that covers many tasks. These tasks can use different mediums such as paper, computer screen, or involve face-to-face meetings. Additionally the tasks can vary in content and may be mainly clerical in nature or may be more specialised such as engineering tasks and CAD work. Points of note are:
Office workers tend to have a sedentary work routine. Therefore they will be looking in essentially the same direction for large amounts of time. Poor lighting can cause various health problems, from headaches due to discomfort glare to muscle strain due to sitting at an awkward angle to avoid reflections in computer screens or glossy publications. Care must be taken to design a lighting installation that minimises discomfort caused by lighting.
A balanced ambience creates a pleasant work environment. Ensuring light falls onto the walls and ceiling helps prevent dark surfaces creating an oppressive atmosphere. Generally, ensuring wall lighting levels are 50% of the horizontal task lighting level and ceiling levels are 30% of the horizontal task level will give a good balance. Careful use of wall-washing luminaires and indirect lighting can help produce a positive environment.
Lamps with a colour-rendering index of 80 or more should be used to enhance visual performance and visual satisfaction.
If the positions of the workstations are known and fixed it is more efficient to design the lighting to supply the correct amount of lighting to the task, but less lighting to circulation areas. For areas that may be reconfigured lighting controls may be used to set the light levels for individual luminaires in an array of luminaires to achieve the same effect.
For rooms containing display screen equipment luminaires with suitable optical control to remove any bright luminance above 65° should be used.
Drawing office
Lighting for technical areas is critical to minimise errors. Any error in a drawing could be costly and potentially dangerous.
Although drawing boards are becoming less common some offices do still use them. In such cases the lighting should provide adequate light levels over a reasonable range of tilt angles of the board, and be positioned so as to minimise shadowing onto the board.
For CAD workstations luminaires should be chosen which have a minimal luminance at high angles from the downward vertical (e.g. angles close to the horizontal plane of the luminaire). When using indirect or direct/indirect luminaires care should be taken to ensure that the ceiling luminance is not too high as this can produce images on the computer screen.
Key luminaires:
Reception desk
Main objective is to provide visitors with a visible first point of contact and employees with a transition zone from exterior and interior lighting levels.
Light naturally attracts people so a well lit reception area and reception desk will help orientate visitors by giving them a visible point of reference.
Luminaires should be placed to help orientation by providing a luminous pathway
Entrances with high ceilings lend themselves to the use of uplighting or suspended lighting, both of which tend to provide good modelling.
Key luminaires:
Office
Conference rooms
Main objectives are to ensure that people have adequate light to perform their tasks (such as reading, writing), that any presentation aids used are clearly visible, and that modelling is suitable to allow good communication between people.
A good vertical illuminance component should exist to aid the visibility of wall-displays and improve modelling. Moderately strong modelling is desirable for formal communication, whilst softer modelling is more suitable for informal or close contact. Modelling is of special importance in areas that may be used by people with special needs who may utilise lip-reading or signing.
Specialised lighting for whiteboards may be installed to ensure good visibility for all participants. These luminaires should not cause glare for the user of the whiteboard and should be positioned to minimise shadowing during use. If audio-visual projectors are used the luminaires should not impede the projector beam and cause shadowing.
Flexible luminaire controls should be employed to allow the use of projectors or other audio-visual equipment and to set a luminous environment suitable for the meeting purpose.
Key luminaires:
General office
Main objective is to ensure that people have adequate light to perform their tasks quickly and accurately without any stress or strain caused by poor light levels or poorly positioned lighting causing visual disability or discomfort.
Whilst recommendations and standards define suitable lighting levels for office based work consideration should also be given to the demands of the task. For work involving small or complex detail lighting levels required for accurate working will be higher than those necessary for more general office tasks. If a minority of people in a large office perform these tasks local
Care should be taken when positioning luminaires and workstations to ensure that the worker does not create shadows on the task. Ensuring that all workstations are lit by more than one luminaire and from a variety of directions can prevent this occurring.
Tasks frequently involve the transfer of paper-based information onto a computer. In many instances special attachments are used to hold the paper next to the computer screen in a vertical or near vertical orientation. Therefore it must be ensured that the vertical illuminance is sufficient to allow good visibility of the paper-based task.
When writing, typing or reading paper-based material the contrast rendering factor (CRF) of the task is important. This indicates how effectively the lighting system minimises unwanted shiny reflections in the task. The CRF is sensitive to the geometry between the luminaires, task and observer and should either be calculated or measured. If the CRF is too low altering the lighting layout or moving the location of the task should be considered.
It should be ensured that light levels on the walls are suitable for comfortable use of notice boards, whiteboards, etc. However, overly aggressive or poorly designed lighting of shiny artefacts on the walls (such as whiteboards or glazed pictures) may result in some workers having problems with reflected glare.
When filing or retrieving information from a storage system it is frequently necessary to read information on a vertical surface, such as the front of a drawer of a filing cabinet. Therefore, adequate vertical illuminance levels should be provided.
Luminaires should be positioned to ensure that the user does not create shadowing over filing systems or copiers when standing in front of them.
Key luminaires:
Office
Schemes
Office lighting
Scheme: Meeting room, 4.4m x 4.4m x 2.8m Luminaire(s) used: 9 Corsa 200 2x26W TC-D Desk: Eav = 468 lux ; Emin/Eav = 0.86
Scheme: Circulation routes, 2.8m wide x 2.8m high Luminaire(s) used: Indi-Quattro 2x36W TC-L on 3m centres
Desk: Eav = 255 lux ; Emin/Eav = 0.41
Scheme: Boardroom, 7m x 6.5m x 2.8m
Luminaire(s) used: 12 Corsa 200 2x26W TC-D and 16 Chalice LV 50W Desk: Eav = 479 lux ; Emin/Eav = 0.62
Recessed MenloSoft luminaires lighting a large open plan office. The appearance of the luminaire gives a lively feel to the ceiling, which might otherwise appear uninteresting. A good distribution of light prevents walls appearing dark and uninviting.
Pendant Planor luminaires lighting a small office area.
Small offices frequently feel enclosed and cramped. The light distribution from the luminaire lights the ceiling and walls, making the space feel larger and more cheerful, and the fittings seem to float in the space.
Recessed luminaires controlled by the SensaLink system (see Section 6.1). The luminaires have integrated detectors allowing them to adjust the lighting levels according to the amount of daylight flowing in from the large window on the edge of the office.
Quattro T Line luminaires with reflector optics in a large open plan office. This minimises potential problems of the lighting causing reflections in computer screens (see Section 6.2) and allows a clean uncluttered feel to the ceiling. Care needs to be taken to prevent dark walls and ceiling making the room feel gloomy and uninviting.
Office
Techniques:
General
The purpose of a school or college building is to provide a facility that aids and promotes learning for all age groups in a safe and fulfilling environment. The lighting should support this aim in all teaching and ancillary areas.
Luminaires need to be physically robust, not easily damaged, and easy to maintain
The ambience of different areas should be suitable for the activity performed there. For example by treating an art or music room as more than just another classroom the lighting can contribute to providing an inspiring atmosphere.
Additional consideration should be given to any uses of the teaching space for extra-curricular activities or adult learning classes. If a large number of older students use the space light levels should be suitable, taking into account deterioration of the eye with age.
Emergency lighting will be required in many parts of the building.
Entrance hall
Main objective is to provide visitors with a visible first point of contact and students and staff with a transition zone from exterior and interior lighting levels.
Light naturally attracts people so a well lit reception area and reception desk will help orientate visitors by giving them a visible point of reference.
Luminaires should be placed to help orientation by providing a luminous pathway
Entrances with high ceilings lend themselves to the use of uplighting or suspended lighting, both of which tend to provide good modelling.
Key luminaires:
Corridors/Staircases
Main objective is to allow students and staff to move around the building safely.
As corridors and staircases are also main exit routes for emergency situations good emergency lighting with way-guidance is necessary. Points of note are:
Bright ceilings and walls can make corridor areas seem more open and appealing.
Wall mounted fittings can model peoples faces better.
Luminaires should be placed to help orientation by providing a luminous pathway
For walls with an interesting texture using luminaires with a significant downlight component positioned close to the wall can create an interesting effect.
Stairs should be well lit and glare free. Lighting should prevent heavy shadowing of steps, but must allow sufficient contrast for people to easily identify changes in level.
Display lighting in corridors should be glare free for corridor users. Special care is needed near stairs to prevent display lights causing glare to people on the staircase.
Key luminaires:
Classrooms/Lecture halls
Main objectives are to ensure that students and staff have adequate light to perform their tasks (such as reading, writing), that students can see any teaching aids used (such as a whiteboard or projected information), that modelling is suitable to allow good communication between students and staff.
A good vertical illuminance component should exist to aid the visibility of wall-displays and improve modelling. Moderately strong modelling is desirable for formal communication, whilst softer modelling is more suitable for informal or close contact. Modelling is of special importance in areas for students with special needs who may utilise lip-reading or signing.
Education
To help in the visibility of written text and diagrams a high contrast rendering factor (CRF) should exist at all desks.
Specialised lighting for blackboards and whiteboards should be installed to ensure good visibility for all students. These luminaires should not cause glare for the user of the blackboard or whiteboard and be positioned to minimise shadowing during use. If audio-visual projectors are used the luminaires should not impede the projector beam and cause shadowing.
For rooms containing display screen equipment luminaires with suitable optical control to remove any bright luminance above 65° should be used Flexible luminaire controls should be employed to allow the use of projectors or other audio-visual equipment. Flexible controls can also maximise the benefits of daylight by dimming selected luminaires under good daylight conditions.
Key luminaires:
Laboratories/Workshops
Main objectives are to ensure that students and staff have adequate light to perform their tasks (such as science experiments or craft projects) and that the lighting aids good visibility and therefore safety. Points of note are:
Light falling on any position should be from multiple sources to prevent heavy shadowing of the task by the student. However a general drift of light should be present to help with modelling, as patterns of light and shade are essential to allow objects to be correctly discerned and to create an interesting environment.
Good colour rendering is required.
For areas using machinery high frequency control gear should be used to prevent any problems with stroboscopic effects resulting in rotating machinery appearing to be stationary.
Key luminaires:
Sports halls
Main objectives are to ensure that students and staff have adequate light to safely participate in sporting activities. These may require visibility of relatively small objects moving at high speed, or visual conditions suitable for the use of gymnastic equipment.
Points of note are:
All required sports should be defined and a design produced for the most stringent requirements.
A good component of vertical illuminance should exist to aid the modelling of objects and people.
Good colour rendering aids in the discrimination of team colours and sporting equipment such as balls, etc. against the hall background.
The lighting should illuminate the entire three dimensional space, allowing high objects to be easily seen.
The infinitely variable viewing positions of sports participants require good glare control.
Luminaires should be robust and have protection against stray objects striking them (such as a wire guard to protect the lamps). Ideally luminaires should be designed and mounted to minimise the risks of object becoming trapped within or behind them.
Lighting controls should be flexible to produce optimum conditions for all required sports.
Key luminaires:
Assembly halls
Main objectives are to produce a suitable visual environment for all activities required within the space. These may be school meetings, rehearsals and performances of school productions, a space for formal written examinations, or others. Points of note are:
This is a place where the school presents itself to visitors at open events such as school open days, meetings with parents or school productions and concerts. Lighting should be designed to project a suitable image for the school.
Education
Lighting control should be flexible to allow for lighting suitable for public meetings, and also lighting that provides the flexibility of a small theatre for public productions and concerts.
Lighting should have no flicker to minimise possible stress in examination conditions.
Lighting should prevent shadowing of the task by the student, such as question papers in formal examinations. Lighting should also gives a good CRF to ensure good visibility of written text and diagrams.
Generally a viewing direction is defined by the hall design. Glare free viewing in this direction should be ensured under all lit conditions.
For areas designed for presentations or performances, such as staging, good vertical illuminance and colour rendering are required to aid in modelling and discrimination.
Key luminaires:
Scheme: Circulation routes, varies x 2.7m high Luminaire(s) used: Chalice 190 2x26W TC-D on 2.4m Floor: Eav = 143 lux ; Emin/Eav = 0.22
Scheme: Storeroom, 1.7m x 3.5m x 2.8m Luminaire(s) used: 1 Diffusalux II 1x35W T16 Floor: Eav = 96 lux ; Emin/Eav = 0.88
Scheme: Classroom, 7.5m x 5.5m x 2.6m
Luminaire(s) used: 6 Omega BD/MB 4x18W T26 and 2 Punch 1x58W T26 lighting front board
Desks: Eav = 518 lux ; Emin/Eav = 0.70
Schemes
Classrooms
Education
Sche me: Ci rculation routes, varies x 2.7m high
Lumi naire(s) used: Ch alice 190 2x26W T C -D o n 2.4m ce ntres.
Lumi naire(s) used: Ch alice 190 2x26W T C -D o n 2.4m ce ntres.