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Lighting Design GuideMains LightingLighting Design GuideMains LightingDesign GuideMains Lighting00

00Huddersfield LightingLeisure CentreDesignHuddersfield Mains Lighting2LIGHTING DESIGN GUIDEGuidewww.eaton.eu

00Lighting Design GuideContentsMains Lighting Design Guide4Lighting Design4Uniformity and Rations of Illuminance4Glare4Colour and Room Reflectance4Energy Efficiency4Special Considerations4Lumen Method Calculations5Polar Intensity Curves6Utilisation Factors Chart6Illuminance Cone Diagrams6Cartesian Diagrams7Isolux Diagram7Interior Lighting Design Guide8Wall and Ceiling Illuminance8Certificate of Conformity9Luminous Environment10Luminance Distribution10Illuminance10Glare12Lighting in the Interior Space12Colour Appearance and Colour Rendering12Flicker and Stroboscopic Effects12Additional Benefits of Daylight13Variability of Light13Practical Scheme Design13Lighting Design Software16Building Regulations18LIGHTING DESIGN GUIDEwww.eaton.eu3

00Lighting Design GuideMains LightingLighting DesignDesigning a basic lighting scheme requiresthe consideration of many factors, not justthe achievement of a desired lighting level.Basic objectives must first be established,such as:– What sort of tasks will be performed inthe area?– What ‘mood’ needs to be created?– What type of lighting will create acomfortable environment?There are also standards and legislation thatneed to be complied with. For example:– How energy efficient must the lightingbe?– How will Building Regulations affect thedesign?– Is emergency lighting required?When all of these objectives andrequirements have been established, theycan be expressed as a series of lightingcriteria in order to facilitate a quality lightingdesign. Criteria that would normally beconsidered are:Level of IlluminationIllumination levels for a wide variety ofenvironments and tasks can be found in BSEN 12464-1: 2011 and the society of lightand lighting’s code for lighting. The levelsstated are maintained illuminance, whichis the minimum average illumination levelthat should be achieved at the point ofscheduled maintenance.Uniformity and Ratios of IlluminanceThe combination of luminaires selectedshould evenly illuminate the working planeand appropriately illuminate walls andceilings in relation to the task illumination,so that a pleasant and comfortableenvironment is achieved. In specific4LIGHTING DESIGN GUIDEwww.eaton.euareas, increased directional lighting maybe required to create a defined or moreintimate environment.GlareThe acceptable level of glare shouldbe established as appropriate for theapplication, using information inBS EN 12464-1: 2011 and the SLL code forlighting.Colour and Room ReflectanceThe colour appearance of the lampsshould be chosen for the applicationand complement the interior colourscheme, which should be chosen with anappreciation of the reflectance values thatwill be achieved. Lamps should be selectedwith appropriate colour rendition propertiesas detailed in EN12464-1 and for colourdiscrimination and reduction of eye fatigue.Energy EfficiencyLuminaires should be selected thatmeet the requirements of the BuildingRegulations Part L. The distributioncharacteristics should also match therequirements of the criteria above.Special ConsiderationsCertain applications require additionalconsiderations, such as the addition ofdisplay lighting, the arduous nature of theenvironment or the use of Display ScreenEquipment. Luminaires should be selectedand the design completed with theseelements in mind, where appropriate.After these criteria have all beenconsidered, a lighting scheme calculationcan be undertaken. The most popularmethod of establishing the quantity ofluminaires required, the illumination levelachieved and the luminaire layout, is touse computer software created specificallyfor lighting design. It is important to

Lighting Design GuideMains Lighting00remember that all the criteria above muststill be considered prior to using computersoftware, if a satisfactory scheme is to beproduced.The maintenance factor is a multiple offactors and is determined as follows:Lighting design can also be achieved usingpublished photometric data, such as thatincluded on the product pages of thiscatalogue. Average illumination via thelumen method of calculation can providefast results that can then be assessed andfacilitate more detailed design of the mostappropriate option if required.Where:Lumen Method CalculationsThis method uses the utilisation factortables created from photometricmeasurement of each luminaire. Firstly,the Room Index (K) of the space must becalculated, which is the relationship andmeasure of the proportions of the room:K LxW(L W) x HmWhere:L length of roomW width of roomHm height ofluminaire aboveworking planeThe result is used in conjunction with roomreflectance values to obtain a specificutilisation factor for the surface illuminatedfrom the tables.This can then be used as part of thecalculation to determine the averageilluminance level, using the followingformula:E LLMF x LSF x LMF x RSMFLLMF lamp lumen maintenance factor the reduction in lumen output afterspecific burning hoursLSF lamp survival factor - thepercentage of lamp failures afterspecific burning hoursLMF luminaire maintenance factor - thereduction in light output due to dirtdeposited on or in the luminaireRSMF room surface maintenance factor the reduction in reflectance due todirt deposition in the room surfacesGuidance on calculating each of thesefactors is provided in the SLL code forlighting. Alternatively, contact our technicalsupport and application department foradvice.Finally, the luminaires must be spaced inthe room such that acceptable uniformity isachieved. The maximum spacing to heightratio, SHRmax, provides the maximumspacing permissible between luminairesin both transverse and axial directions, incomparison to the mounting height andshould not be exceeded if acceptableuniformity is to be achieved.F x n x N x MF x UFAWhere:EFnNMFUFAMF average illuminanceinitial lamp lumensnumber of lamps in each luminairenumber of luminairesmaintenance factorutilisation factorareaLIGHTING DESIGN GUIDEwww.eaton.eu5

00Lighting Design GuideMains LightingUsing Photometric DataThis catalogue includes a number of different formats of photometric data, to assist inlighting design.Polar Intensity CurvesThis illustrates the distribution of luminousintensity, in cd/1000 lm, for the transverse(solid line) and axial (dashed line) planes ofthe luminaire. The curve provides a visualguide to the type of distribution expectedfrom the luminaire, e.g. wide, narrow,direct, indirect etc, in addition to intensity.Utilisation factors show the proportionof the luminous flux from the lamp thatreaches the working plan. This is for thespecific luminaire and allows for surfacereflectivity and Room Index. The UF is usedin average lumen calculations to calculatethe average illumination level for an areawith a specific luminaire.Cat. No. LCTL414Zcd/1000lm120 120 90 90 LOR:ULOR:DLOR:0.860.090.85SHR nom: 1.75SHR max: 1.7910060 60 20030030 30 Utilisation factors / TM5ReflectancesRoom IndexC W F0.75 1.0 1.25 1.5 2.0 2.570 50 20N/A 66 72 76 81 8570 30 20N/A 60 66 71 77 8170 10 20N/A 56 62 67 73 7850 50 20N/A 64 70 73 79 8250 30 20N/A 59 65 69 75 7850 10 20N/A 56 61 66 72 7630 50 20N/A 63 68 71 76 7930 30 20N/A 58 64 68 73 7630 10 20N/A 55 61 65 70 740 0 0N/A 53 58 62 67 71BZ-class1 22 2223.0 4.0 5.087 90 9284 87 9081 85 8884 87 8981 84 8678 82 8581 83 8578 82 8376 80 8273 76 78333 Illuminance Cone DiagramsUsually used for spotlights or lamps withreflectors, the diagram indicates themaximum illuminance, E lux, at differentdistances, plus the beam angle of the lampover which the luminous intensity dropsto 50%. The beam diameter at 50% peakintensity, relative to distance away, is alsoshown. 6LIGHTING DESIGN GUIDEwww.eaton.eu

00Lighting Design GuideMains Lighting Cartesian DiagramsGenerally used for floodlights, this indicatesthe distribution of luminous intensity, incd/1000 lm, for the horizontal (solid line) andvertical (dashed line) planes of the luminaire.The diagram provides a visual guide tothe type of distribution expected from theluminaire e.g. narrow or wide beam etc, inaddition to intensity. The associated dataillustrates the beam angle to 10% peakintensity. Isolux DiagramsThe contours provide the points of equalilluminance, in lux, on the floor or wallplane, from a specific stated mountingposition.The diagram can be used to assess thedistribution characteristics of the luminairein addition to determining lighting levels. The society of light and lighting produce a number of design guides (LG) for specificapplications which offer useful design advice for best practice approach to illuminatingthese areas. A sample of the available guides are: Lighting Guide 02: Hospitals andHealthcare Buildings, Lighting Guide 04: Sports Lighting, Lighting Guide 05: Light forEducation, Lighting Guide 07: Office Lighting and Lighting Guide 08: Lighting for Museumsand Art Galleries.Useful Website Addresseswww.sll.org.uk - The Society of Light and Lightingwww.cibse.org - The Chartered Institution of Building Services Engineerswww.bsi-global.com - British StandardsLIGHTING DESIGN GUIDEwww.eaton.eu7

00Lighting Design GuideInterior LightingUsing Photometric Data (cont.)There is a wide range of lighting applicationstandards and guides available to aid thedesigner in creating a comfortable andefficient working space.The recent updated edition of BS EN12464-1:2011, which not only sets astandard for illumination levels for specifictasks but, also provides advice on howto achieve a lighting solution to meet thehuman need. Also the SLL lighting designguides provides a very good source ofguidance for the design of working spaces,and can be considered as best practice.Lighting guide (LG) 7 is possibly the onemost commonly referred to, but it is oftenmisunderstood being used to specifyluminaires rather than the total environmentof the space.LG7 was written to supersede the originalLG3 which had very restrictive cut offcriteria for the luminance of luminaires.With the development of improved andflatter VDT screens this could be relaxed,allowing for higher luminance values fromthe luminaire. The increase being 3000cd/m2 or 200 cd/m2 if the screen type isunknown. This can be increased up to 1500cd/m2 and 500 cd/m2 respectively if positivepolarity software only is used. LG7 alsorecommends values for the wall and ceilingilluminance, which are based on a directpercentage of the working plane level.The intention being to alleviate the “cavelike” appearance that the single use ofthe original Category 2 cut off luminairesproduced.The LG7 lighting guide for officelighting was amended in 2012 to alignwith EN12464-1. This changed therecommendation for the wall and ceilingilluminances to be a percentage of thatof the working plane to specific levels8LIGHTING DESIGN GUIDEwww.eaton.euof illumination (lux) with a minimumuniformity.In addition the recommended range for thecd/m2 for luminaires at the relevant cut offangle was changed and now has a rangeof 1000-1500 cd/m2 for screens havingluminances (brightness) of less than 2000cd/m2 which increases to 3000 cd/m2 forscreens with higher luminances.It must be stated that LG7 is often referredto as being guidance for luminaires but itwas written as a complete guide for lightingof the office environment, taking intoaccount the total need of the occupants tocreate pleasant working space.Recommendation for Wall and CeilingIlluminanceThe guide provides recommendations toaddress the dark and gloomy effect thatcan be created by ‘categorised’ louvres,including the sharp wall cut off and brightscalloping. To avoid this, walls and theceiling should be lit as follows:- The average wall illuminance above theworking plane should be at least 75 luxwith a uniformity of 0.1- The ceiling average illuminance should beat least 50 lux with a uniformity of 0.1The other misconception is that officelighting is all about creating a uniformlighting level across the whole space.What is needed is uniform lighting acrosseach task area, which normally consists ofrelatively small areas on each desk. Thelighting in the wider office space can, andindeed should, vary somewhat to createvisual interest. Even the most dedicatedoffice worker looks up from his or her workfrom time to time, and when they do they

Lighting Design GuideInterior Lightingneed to see an interestingly lit office spaceand, ideally, a more distant view out of awindow.If the building and the visual requirementsof the users of an office space areunderstood and all possible lighting optionsare considered, a lit environment can becreated for each office space that not onlyprovides the required levels of lighting foreach task but also provides an interestingand stimulating lit environment for peopleto work in.This is a direct quote from the introductionof LG7 which goes on to discuss the wholedesign process. The overall intention ofthe guide has not been fully utilised bythe majority of users and the reliance on a“single luminaire solution” has still beenwidely requested. The single luminaireapproach when used in regular arraysto produce a high level of uniformityacross the whole working space can be incontradiction to the original intent.If designing to LG7 the certificate ofconformity should be used to show thecriteria of the design.00EN12464-1:2011The lighting design