Holophane Lighting Fundamentals

7/30/2019 Holophane Lighting Fundamentals

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T h e F u n d a m e n t a l s o f L i g h t i n g

HL-862 7/07

RESEARCH ANDDEVELOPMENT

LIGHTING BASICS

LIGHT SOURCES ANDLAMP CHARACTERIST

PHOTOMETRY

CALCULATIONS

COMPUTER TOOLS

LIGHTING QUALITY


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T h e F u n d a m e n t a l s o f L i g h t i n g

HOLOPHANE | THE FUNDAMENTALS OF LIGHTING

1893: BLONDEL PRISMS PATENTED

Prisms, when properly placed, control light.Holophane acquires rights to glass globes: 1895.

IndexIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Holophane Research and Development . . .3 - 5

Lighting Basics . . . . . . . . . . . . . . . . . . . . . . . . . . 6Luminous Flux

Luminous Intensity

Illuminance

Luminance

Exitance

Metric conversions

Light Sources and Lamp Characteristics . . .7 - 8Incandescent

Fluorescent

Induction

High Intensity Discharge

Mercury Vapor

Metal Halide

High Pressure Sodium

Low Pressure Sodium

Photometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Candlepower Distribution Curve

Coefficient of Utilization

Isofootcandle Chart

Spacing Criteria

The Zonal Cavity Method forIndoor Calculations . . . . . . . . . . . . . . . . . . 10 - 12

Methods of Calculating Illuminance

Zonal Cavity Method

The Lumen Method forOutdoor Calculations . . . . . . . . . . . . . . . . . 13 - 14

Utilization Curve Method

Point by Point Method

Visual 2.3 Professional Edition . . . . . . . . . . . .15

Lighting Quality . . . . . . . . . . . . . . . . . . . . . . . . 16

Introduction

Illuminance is light falling on a surface measured in footcandles or

lux. Distributed with an economic and visual plan, it becomes

engineered lighting and, therefore, practical illumination.

A lighting designer has four major objectives:

1. Provide the visibility required based on the task to be performed and

the economic objectives.

2. Furnish high quality lighting by providing a uniform illuminance

level, where required, and by minimizing the negative effects of

direct and reflected glare.3. Choose luminaires aesthetically complimentary to the installation with

mechanical, electrical and maintenance characteristics designed to

minimize operational expense.

4. Minimize energy usage while achieving the visibility, quality and

aesthetic objectives.

There are two parts to the solution of a design problem:

1. To select luminaires which are designed to control the light in

an effective and energy efficient manner.

2. To apply them to the project with all the skill and ingenuity

the designer can bring to bear from his or her ownknowledge and all the reliable sources available.

This primer has been developed to give the designer a useful

summary of basic lighting principles. It gives important data and

practical information on how to apply them. It offers the assistance

of the Holophane technical sales force, who have Visual application

software and SALE economic analysis software at their disposal.

The facilities and staff of the Holophane Technical Support Group

are also available.

In addition, it prefaces a selection of quality lighting products that

use the best design and manufacturing techniques of illumination

science and technology available today. Their use assures the

ultimate in lighting quality, economy, light distribution, energy

efficiency and glare control.

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The high-caliber performance characteristic of Holophane

luminaires is a result of quality in concept, research,

development and execution. This depends on a staff with

ability and integrity, along with the physical plant andequipment to carry on their work. The following are some

brief aspects of the more important activities and facilities

vital to the creation of quality Holophane lighting products

Photometers

The Holophane Photometry Lab follows standards set by the Illuminating

Engineering Society of North America.

A single-cell spinning mirror photometer (A) with the capability of

measuring every 1. A full-scale radial photometer (B) with a radiusof 25 that will accommodate up to an 8 long or 5 square luminai

There are photocells along the arc every 2 1/2, starting at 0 (nadir

up to 180 (zenith). Each luminaire that is tested is rotated to

measure up to 72 planes of data. The systems are fully automated;

the photocell readings are sent directly to an in-house computer

which generates Photometric Test Reports used for calculation and

analysis. Photometric reports are available in IESNA format on our

Web site for use in Visual and other lighting application programs.

Ballast and Electric Laboratory

Heavy-current laboratory will simulate various field power and load

situations. Ballasts are designed and tested to ensure that they operawithin applicable American National Standards Institute (ANSI) desig

limits. A properly designed ballast will optimize its own life while

providing full lamp life and light output.

Thermal Laboratory

Heat testing facility where luminaires and components are subjected

to heat conditions well in excess of their normally expected exposur

under field use. While this laboratory is used for research and

development of luminaires, a significant part of its activities is direct

to the meeting and maintenance of Underwriters Laboratories

requirements.

Holophanes Electric and Thermal Labs are UL certified and are

audited annually for compliance.

B

B

A

A

D

D

C

Research and Development


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1900: HOLOPHANE DIBDEN PHOTOMETER

WAS INTRODUCED

Holophane engineers developed the first method tomeasure light intensity and distribution.


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Vibration Laboratory

Stability of equipment under a variety of vibration loadings is

rigorously tested to meet specifications and field-use conditions.

This assures product reliability when luminaires and poles aresubjected to various wind conditions.

Water Spray Facilities

Resistance to water penetration is evaluated in this closed cycle

water spray system. Luminaires can be tested for standard UL

wet-location and outdoor marine suitability. Also, a special

100-gallon per minute, 100-psi spray can be used to test such

severe conditions as those found in tunnels.

CAD System

A Computer Aided Design system is used for the precise design

of optical and fixture components to assure precise light control

and manufacturing tolerances from all the elements that make

up the luminaire assembly.

Light and Vision Center

A facility for teaching principles of lighting design and calculation,

as well as a center for the consideration of lighting problems in

consultation with recognized experts in the field.

Seminars on lighting for industrial, retail and roadway

applications are conducted, as well as schools for electrical

distributors and utility personnel. Contact your local Holophane

representative for a schedule.

Lighting Demonstration Center

In this laboratory, complete luminaires and systems are installed for

measurement and visual evaluation of performance. The room is highly

flexible, and mounting heights can be altered to duplicate various

lighting conditions.

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R e s e a r c h a n d D e v e l o p m e n t

E

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G

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1906: IESNA WAS FORMEDThree prominent Holophane engineers were

instrumental in the formation and earlyorganization of the Society.

H

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Outdoor Lighting Laboratory

A street and parking lot area arranged for the measurement and visual

evaluation of a variety of lighting systems, including sign lighting. Outdoo

architectural, historical and municipal luminaires may also be examined inan adjacent park-like setting

Lighting Design Department

A department staffed with professional lighting designers and engineers,

to aid consultants and users in reaching their lighting decisions. The

department uses various lighting analysis programs for their lighting

designs.

Optical Laboratory

A visual evaluation facility to aid in the optical design of high quality light

control elements of Holophane luminaires.

Materials Laboratory

A facility for the testing of materials for strength, corrosion resistance and

other properties related to luminaires.

Model Shop

A complete wood and metal working shop for the preparation of model

and working prototypes of luminaires under design.

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1920: THEBIRTH OF HIGH BAYLIGHTING

Holophane develops high bay lighting, whichwould be used to effectively light large factories.

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An understanding of some of the fundamental terms in lighting technology is basic

to good design practice. The more important terms and concepts are reviewed here

for this purpose.


Lighting Basics

1 fc 1/4 fc

D = 1 ft.

D = 2 ft.

Luminous fluxLuminous flux is the time rate of flow of light asmeasured in lumens. It is a measure of the totallight emitted by a source and is most commonlyused for measurement of total lamp output.

Luminous intensity (I)The candela is the unit of intensity (I) and isanalogous to pressure in a hydraulic system. It issometimes called candlepower and describesthe amount of light (lumens) in a unit of solidangle. This unit of solid angle is called thesteradian. It will be seen from Figure 1 that asthe light travels away from the source the solidangle covers a larger and larger area; but theangle itself remains the same, as does theamount of light it contains. Intensity therefore, ina given direction is constant regardless ofdistance. See Figure 1

Illuminance (E)Illuminance is the quantity of light reaching aunit area of surface and is measured in footcandlesor lux. As the area covered by a given solid angle

becomes larger with distance from the source,the included light flux remains the same. Theillumination density of light on the surfacedecreases, therefore, with the square of thedistance. Illuminance is defined by the intensity() in candelas directed toward point P, divided bythe square of the distance (D) from the source tothe surface.

This formula holds only if the receiving surface isperpendicular to the source direction. If light isincident at some other angle, See Figure 2, theformula becomes:

where E = illuminance in footcandles (fc) or luxI = intensity in candelas (cd) toward point P

D = distance in feet or meters

O = angle of incidence

Luminance (L)Luminance, often called brightness, is thename given to what we see. Brightness is asubjective sensation varying from very dim ordark to very bright. Objectively it is referred toas luminance, defined as intensity in a givendirection divided by a surfaces projected areaas seen by the observer. The surface may be aluminaire surface or a reflecting surface, suchas a wall or roadway.

The direct luminance, or brightness, of luminaireat various angles of view is a major factor in thevisual comfort evaluation of an installation using

those luminaires. In general, it is desirable tominimize the brightness of ceiling mountedluminaires at the high vertical angles, 60-90.When the intensity is in candelas, and theprojected area is in meters, the unit of luminanceis candelas per square meter (cd/m2).

Exitance (M)It is often desirable to calculate the amountof light reflected from room surfaces. Thetotal amount of light reflected, regardless ofdirection, is Exitance. Exitance = illuminancex reflection factor

Where E = Illuminance in footcandles

= the reflection factor of the surfaceexpressed as the percentage oflight reflected

M = the resulting exitance in lumensper square foot

Metric systemAs the U.S.A. moves toward conversion to themetric system to conform with the scientificfields and the rest of the world, our illuminationengineering will convert to the InternationalSystem of Units (SI). Only the terms involvinglength or area, illuminance and luminance, areaffected. Illuminance (E) is stated in lux (lumensper sq. meter) in the metric system. 1fc = 10.76lux. Luminance (L) is stated in nits (candelas persq. meter) in the metric system.

D

I

P

I = (lumens)(steradians)

E =I

D2

M = E x

E = I cos OD2

1930: LOWBAYPRIMARYSOURCE FORINDUST

FACILITIES

Holophane developed the first reflector specificallydesigned to utilize mercury vapor lamps.6

Figure 1

Figure 2


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IncandescentAn incandescent filament lamp is the light source most commonly used inresidential lighting. Light is produced in this source by a wire or filament beingheated to incandescence (emitting light) by a flow of current through it. Theshort life and low efficacy (lumens per watt) of this source limit its use mostlyto residential and decorative commercial lighting. Efficacy varies with wattageand filament type, but generally ranges from 15 to 25 lumens per watt forgeneral service lamps.

The incandescent source does, however, produce light in a well accepted warmtone. It is more convenient than other light sources because it can be run directlyon line current and therefore does not require a ballast. It can also be dimmedusing relatively simple equipment. It is available in different bulb sizes, shapesand distributions to add a decorative touch to an area.

FluorescentThe fluorescent lamp produces light by activating selected phosphors on theinner surface of the bulb with ultraviolet energy, which is generated by a mercuryarc. Because of the characteristics of a gaseous arc, a ballast is needed to startand operate fluorescent lamps.

The advantages of the fluorescent light source include improved efficacy andlonger life than incandescent lamps. Efficacies for fluorescent lamps rangeanywhere from 50 to 100 lumens per watt. Their low surface brightness andheat generation make them ideal for offices and schools where thermal andvisual comfort are important.

The disadvantages of fluorescent lamps include their large size for the amount oflight produced. This makes light control more difficult, which results in a diffuse,shadowless environment. Their use in outdoor areas becomes less economicalbecause light output of a fluorescent source is reduced at low ambienttemperatures.

InductionInduction lamps are electrodeless fluorescent lamps driven by high-frequencycurrent, typically between 250kHz and 2.65mHz, usually via an externalgenerator. They are available in limited wattages and are known for exceptionalong service life: up to 100,000 hours. Lamp efficacies typically range from 64to 88 lumens per watt. Color rendition with induction lamps is very good.Although not easily optically controllable in a luminaire because of the large lamsize, induction lighting is often employed in applications where luminaires maybe very difficult to access or where maintenance costs are a strong factor in thlighting design and installation. Initial system purchasing costs are high compato the best HID or fluorescent systems.

High Intensity Discharge (HID) and LPSHigh intensity discharge sources include mercury vapor, metal halide, and highpressure sodium (HPS) lamps. Light is produced in HID and low pressure sodiu(LPS) sources through a gaseous arc discharge using a variety of elements. EachHID lamp consists of an arc tube which contains certain elements or mixtures oelements which, when an arc is created between the electrodes at each end,gasify and generate visible radiation.

The major advantages of HID sources are their high efficacy in lumens per wattlong lamp life and point-source characteristic for good light control. Disadvantag

include the need for a ballast to regulate lamp current and voltage as well as astarting aid for HPS and some MH and the delay in restriking after a momentapower interruption.

Light Sources and Lamp Characteristics

Light Sources and Lamp Characteristics

One of the first decisions in the design

of a good lighting system is the choice of

a light source. A number of light sources

are available, each with its own unique

combination of operating characteristics.

A few of the lamp characteristics that a

lighting designer should consider when

choosing a light source include efficacy,

or lumens per watt; color; lamp life; and

lamp lumen depreciation, or the percent

of output that a lamp loses over its life.

Although there are hundreds of lamps on the market today, they can be categorized by construction andoperating characteristics into three main groups: incandescent, fluorescent and high intensity discharge (HID).HID lamps can be grouped into three major classes: high pressure sodium, metal halide and mercury vapor.Another type of lamp, low pressure sodium (LPS), shares some characteristics of HID lamps. Induction lampsare a special type of fluorescent.

1930S: FIRST VAPOR-PROOF FIXTURES FOR

HAZARDOUS AREAS

Holophane introduced the first fixture ideal for acidplants, distilleries, oil refineries, and power plants.


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Mercury Vapor (MV)The mercury vapor source was the first HID lamp developed, filling the needfor a more efficient, yet compact, high output lamp. When first developed, themajordisadvantage of this lamp was its poor color rendition. The color of thedeluxe white lamp is somewhat improved through use of a phosphor coated

bulb wall.The life of mercury vapor lamps is good, averaging 24,000 hours for most largerwattage lamps. However, because the output diminishes so greatly over time,economical operational life is often much shorter. Efficacy ranges from 30 to 60lumens per watt, with the higher wattages being more efficacious than the lowerwattages.

As with other HID lamps, the starting of a mercury vapor lamp is not immediate.Starting time is short, though, taking 4-7 minutes to achieve maximum outputdepending upon the ambient temperature.

High Pressure Sodium (HPS)In the 1970s, as increasing energy costs placed more emphasis on the efficiencyof lighting, high pressure sodium lamps (developed in the 1960s) gainedwidespread usage. With efficacies ranging from 80 to 140 lumens per watt,

these lamps provide about 7 times as much light per watt as incandescent andabout twice as much as some mercury or fluorescent. The efficacy of this sourceis not its only advantage. An HPS lamp also offers the longest life (24,000+ hrs.)and the best lumen maintenance characteristics of all HID sources.

The major objection to the use of HPS is its yellowish color and low colorrendition. It is ideal mainly for some warehouse and outdoor applications.

Metal Halide (MH)Metal halide lamps are similar in construction to mercury lamps with the additionof various other metallic elements in the arc tube. The major benefits of this changeare an increase in efficacy to 60 to 100 lumens per watt and an improvement incolor rendition to the degree that this source is suitable for commercial areas.

Light control of a metal halide lamp is also more precise than that of a deluxemercury lamp since light emanates from the small arc tube, not the total outerbulb of the coated lamp.

Pulse-start metal halide lamps have several advantages over standard (probe-start)metal halide: higher efficacy (110 lumens per watt), longer life, and betterlumen maintenance.

A disadvantage of the metal halide lamp is its shorter life (7,500 to 20,000 hrs)as compared to mercury and high pressure sodium lamps. Starting time of themetal halide lamp is approximately the same as for mercury lamps. Restrikingafter a voltage dip has extinguished the lamp, however, can take substantiallylonger, ranging from 4 to 12 minutes depending on the time required for thelamp to cool.

Low Pressure Sodium (LPS)

Low pressure sodium offers the highest initial efficacy of all lamps on the markettoday, ranging from 100 to 180 lumens per watt. However, because all of theLPS output is in the yellow portion of the visible spectrum, it produces extremelypoor and unattractive color rendition. Control of this source is more difficult thanwith HID sources because of the large size of the arc tube. The average life oflow pressure sodium lamps is 18,000 hours. While lumen maintenance throughlife is good with LPS, there is an offsetting increase in lamp watts, reducing theefficacy of this lamp type with use.


1940S: HOLOPHANEEARNS E AWARD

FORWARCONTRIBUTIONSHolophane was very involved in the war effort, from sta

to finish, lighting war plants, airplane hangars, anddeveloping signaling equipment for submarines.

L i g h t S o u r c e s a n d L a m p C h a r a c t e r i s t i c s

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Photometry means the measurement of light. The term photometry

is often used to define any test data which describe the characteristics

a luminaires light output. The most common type of photometric da

include candlepower distribution curves, spacing criteria, luminaireefficiency, isofootcandle charts, coefficients of utilization and luminan

data. The purpose of a photometric report is to accurately describe th

performance of a luminaire, to enable the designer to select the lighting

equipment and design a fixture layout which best meets the needs of

the job.

Following is a review of the more frequently used types of photometric data

Candlepower distribution curveThe photometric distribution curve is one of the lighting designers most valuable

tools. It is a cross-sectional map of intensity (candelas) measured at many differevertical angles. It is a two-dimensional representation and therefore shows data foone plane only. If the distribution of the unit is symmetric, the curve in one plane sufficient for all calculations. If asymmetric, such as with street lighting and fluoresceunits, three or more planes are required. In general, incandescent and HID reflectunits are described by a single vertical plane of photometry. Fluorescent luminairerequire a minimum of one plane along the lamp axis, one across the lamp axis anone at a 45 angle. The greater the departure from symmetry, the more planes thare needed for accurate calculations. See figure 1

Coefficient of utilizationA coefficient of utilization refers to the ratio of lumens which ultimately reach thework plane to the total lumens generated by the lamp. CU figures are necessary fhand calculating average illuminance levels and are provided in one of two ways:

CU table or a utilization curve. A utilization curve is usually provided for unitsintended for outdoor use or units with a distribution radically asymmetric. A CUtable is provided for units which are used primarily indoors. Use of CU data will bdiscussed in the section covering calculation methods. See figure 2

Isofootcandle chartIsofootcandle charts are used to describe the light pattern produced by a luminairThese charts are derived from the candlepower data and show exact plots or lineof equal footcandle levels on the work plane when the fixture is at a designatedmounting height. Use of isofootcandle charts in determining illuminance atdesignated points will be discussed in the point calculations section. See figure 3

Spacing criteria

Spacing criteria provide the designer with information regarding how far apart luminairmay be spaced while maintaining acceptable illumination uniformity on the workplane. Criteria for spacing are generally conservative; they take into account the direccomponent of illumination only and ignore the indirect component of light, whiccan contribute significantly to the uniformity. However, used within its limits, aSpacing Criterion can be useful. To use the Spacing Criterion, multiply the netmounting height (luminaire to work plane) by the Spacing Criterion number. Thisratio is used predominantly with the Zonal Cavity Method of calculation.

Photometry

Photometry

PHOTOMETRIC TEST REPORTHOLOPHANE CORPORATIONHOLOPHANE RESEARCH & DEVELOPMENT CENTERNEWARK, OHIO 43055

DISTRIBUTION DATA

VERTICAL

ANGLE

CANDLE

POWERZONAL

LUMENS

ZONAL

LUMENS

ZONAL

DEGREES

TOTAL

EFFIC.

OUTPUT DATATEST OF HOLOPHANE

BL2X250MHXXM PRISMGLO MENTOR

POSITION OF LAMP Set Position

LAMP 250W Coated MH LUMENS 23000

WATTS 250 BULB TYPE E-28

TEST DISTANCE 25 ft. S.C. 1.8

TESTED BY CERTIFIED BY

MANAGEROFENGINEERING

TEST NO.

030 30

6060

90 90

120 120180150 150

42343

0 23055 2236 213

10 214215 2158 61220 2140

25 2153 99730 230635 2451 154040 264545 2771 2146

50 261655 2212 198560 172465 1324 131570 1015

75 818 86580 72485 677 73990 67595 745 813

105 1063 1124115 1917 1903125 2063 1851135 1646 1275145 1252 786

155 881 408165 572 162175 431 41180 341

0-30 1822 8.930-60 5671 27.760-90 2919 14.20-90 10411 50.8

90-180 8363 40.80-180 18774 91.6

600 CD/DIV

fc

cc

w

RCR

0123456789

10

.99 .99 .99 .92 .92 .92 .79 .79 .79

.85 .80 .77 .78 .75 .72 .67 .64 .62

.73 .67 .61 .68 .62 .57 .58 .54 .50

.63 .56 .50 .59 .52 .47 .50 .45 .41

.56 .48 .42 .52 .45 .39 .44 .39 .34

.49 .41 .35 .46 .38 .33 .39 .33 .29

.44 .36 .30 .41 .33 .28 .35 .29 .25

.39 .31 .26 .36 .29 .24 .31 .26 .22

.35 .28 .23 .33 .26 .21 .28 .23 .19

.32 .25 .20 .30 .23 .19 .26 .20 .17

.29 .22 .18 .27 .21 .17 .24 .18 .15

20%

80% 70% 50%

50% 30%10% 50%30%10% 50%30% 0%

Coefficient of Utilization

Isofootcandle chart

150W HPS at (10) 3.05m mountingTest No. 34673

HOUSESIDE

STREET SIDE

Ratio=Distanc

ealong/Mountingheight

Coefficientsofultilization

(dashedcurves)

8

7

6

5

4

3

2

1

02 1 0 1 2 3 4 5

.1

.2

.5

1

2

5

Ratio = Distance across/Mounting height

.8

.7

.6

.5

.4

.3

.2

.1

0

Figure 1

Figure 2

Figure 3

1950S: THEREVOLUTIONARY WALLPACK UNIT

The first fixture to rest tightly against the wall, eliminatingprotruding surfaces in tunnels and underpasses.


10/16HOLOPHANE

| THE FUNDAMENTALS OF LIGHTING

1970S: THEREVOLUTIONARY HIGH MASTSYSTEMS

Holophane develops the first lighting system to raise anlower for ground-level servicing.

Zonal Cavity Method for Indoor Calculations

Methods of calculating illuminanceIn order to design a luminaire layout that best meets the illuminance and uniformityrequirements of the job, two types of information are generally needed: averageilluminance level and illuminance level at a given point. Calculation of illuminance

at specific points is often done to help the designer evaluate the lighting uniformity,especially when using luminaires where maximum spacing recommendations arenot supplied, or where task lighting levels must be checked against ambient.

If average levels are to be calculated, two methods can be applied:

1. For indoor lighting situations, the Zonal Cavity Method is used with datafrom a coefficient of utilization table.

2. For outdoor lighting applications, a coefficient of utilization curve is provided,the CU is read directly from the curve and the standard lumen formula isused.

The following two methods can be used if calculations are to be done todetermine illuminance at one point.

1. If an isofootcandle chart is provided, illuminance levels may be read directlyfrom this curve.

2. If sufficient candlepower data are available, illuminance levels may becalculated from these data using the point-to-point method.

The following sections describe these methods of calculation.

Zonal Cavity Method

The Zonal Cavity Method (sometimes called the Lumen Method) is the currentlyaccepted method for calculating average illuminance levels for indoor areas,unless the light distribution is radically asymmetric. It is an accurate hand methodfor indoor applications because it takes into consideration the effect that inter-

reflectance has on the level of illuminance. Although it takes into account severalvariables, the basic premise that footcandles are equal to luminous flux over anarea is not violated.

The basis of the Zonal Cavity Method is that a room is made up of three spacesor cavities. The space between the ceiling and the fixtures, if they are suspended,is defined as the ceiling cavity; the space between the work plane and thefloor, the floor cavity; and the space between the fixtures and the work plane,the room cavity.

Once the concept of these cavities is understood, it is possible to calculatenumerical relationships called cavity ratios, which can be used to determinethe effective reflectance of the ceiling and floor cavities and then to find thecoefficient of utilization.

There are four basic steps in any calculation of illuminance level:

1. Determine cavity ratios

2. Determine effective cavity reflectances

3. Select coefficient of utilization

4. Compute average illuminance level

hcc

hrc

hfc Floor

Workplane

Luminaires

Ceiling Ceiling Cavity

Room Cavity

Floor Cavity

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11/16Zonal Cavity Method for Indoor Calculations

1980S: THEGRANVILLE SPARKS A ROMANCE

WITH HISTORICALLYSTYLED STREET LIGHTING

The acorn, a turn-of-the-century replica, offers the lookof yesteryear with state-of-the-art technology.

Step 1: Cavity ratios for a rectangular space may be calculated by using

the following formulas:

Step 2: Effective cavity reflectances must be determined for the ceiling

cavity and for the floor cavity. These are located in Table A (see below) underthe applicable combination of cavity ratio and actual reflectance of ceiling,walls and floor. The effective reflectance values found will then be cc(effective ceiling cavity reflectance) and fc (effective floor cavity reflectance).Note that if the luminaire is recessed or surface mounted, or if the floor is thework plane, the CCR or FCR will be 0 and then the actual reflectance of theceiling or floor will also be the effective reflectance.

Step 3: Coefficient of utilization: With these values of cc, fc, and w (wallreflectance), and knowing the room cavity ratio (RCR) previous ly calculated,find the coefficient of utilization in the luminaire coefficient of utilization (CU)table. Note that since the table is linear, linear interpolations can be made forexact cavity ratios and reflectance combinations.

Ceiling Cavity Ratio (CCR) =5 hcc (L+W)

L x W

Room Cavity Ratio (RCR) =5 hrc (L+W)

L x W

Floor Cavity Ratio (FCR) =5 hfc (L+W)

L x W

Where:hcc = distance in feet from luminaire to ceilinghrc = distance in feet from luminaire to work planehfc = distance in feet from work plane to floor

L = length of room, in feetW = width of room, in feet

An alternate formula for calculating any cavity ratio is:

Cavity Ratio =2.5 x height of cavity x cavity perimeter

area of cavity base

The coefficient of utilization found will be for a 20% effective floor cavityreflectance. Thus, it will be necessary to correct for the previously determinfc. This is done by multiplying the previously determined CU by the factorfrom Table B (pg.12).

CU final = CU (20% floor) x Multiplier for actual fc. If it is other than 10% 30%, interpolate or extrapolate and multiply by this factor.

Step 4: Computation of the illuminance level is performed using the

standard Lumen Method formula.

When the initial illuminance level required is known and the number of fixturneeded to obtain that level is desired, a variation of the standard lumen formuis used.

The total light loss factor (LLF) consists of three basic factors: lamp lumendepreciation (LLD), luminaire dirt depreciation (LDD) and ballast factor (BF). Iinitial levels are to be found, a multiplier of 1 is used. Light loss factors, alonwith the total lamp lumen output, vary with manufacturer and type of lamplu minaire and are determined by consulting the manufacturers published da

Ballast factor (BF) is defined as the ratio between the published lamp lumenand the lumens delivered by the lamp on the ballast used. Typical HID ballasfactors vary between .9 and .95. Holophane ballasts are designed to have aBF=1.0.

Occasionally, other light loss factors may need to be applied when they areapplicable. Some of these are luminaire ambient temperature, voltage factoand room surface dirt depreciation.

Table APercent effective ceiling or floor cavity reflectance for various reflectance combinations.

% Ceiling or floor 90 80 70 50 30 10reflectance

% Wall reflectance 90 70 50 30 80 70 50 30 70 50 30 70 50 30 70 50 30 10 50 30 10

Cavity ratio0.2 89 88 86 85 78 78 77 76 68 67 66 49 48 47 30 29 29 28 10 10 090.4 88 86 84 81 77 76 74 72 67 65 63 48 47 45 30 29 28 26 11 10 090.6 87 84 80 77 76 75 71 68 65 63 59 47 45 43 30 28 26 25 11 10 080.8 87 82 77 73 75 73 69 65 64 60 56 47 44 40 30 28 25 23 11 10 081.0 86 80 75 69 74 72 67 62 62 58 53 46 43 38 30 27 24 22 12 10 08

1.2 85 78 72 66 73 70 64 58 61 57 50 45 41 36 30 27 23 21 12 10 071.4 85 77 69 62 72 68 62 55 60 55 47 45 40 35 30 26 22 19 12 10 071.6 84 75 67 59 71 67 60 53 59 53 45 44 39 33 29 25 22 18 12 09 071.8 83 73 64 56 70 66 58 50 58 51 42 43 38 31 29 25 21 17 13 09 062.0 83 72 62 53 69 64 56 48 56 49 40 43 37 30 29 24 20 16 13 09 06

2.2 82 70 59 50 68 63 54 45 55 48 38 42 36 29 29 24 19 15 13 09 062.4 82 69 58 48 67 61 52 43 54 46 37 42 35 27 29 24 19 14 13 09 062.6 81 67 56 46 66 60 50 41 54 45 35 41 34 26 29 23 18 14 13 09 062.8 81 66 54 44 65 59 48 39 53 43 33 41 33 25 29 23 17 13 13 09 053.0 80 64 52 42 65 58 47 37 52 42 32 40 32 24 29 22 17 12 13 09 05

3.2 79 63 50 40 65 57 45 35 51 40 31 39 31 23 29 22 16 12 13 09 053.4 79 62 48 38 64 56 44 34 50 39 29 39 30 22 29 22 16 11 13 09 053.6 78 61 47 36 63 54 43 32 49 38 28 39 29 21 29 21 15 10 13 09 043.8 78 60 45 35 62 53 41 31 49 37 27 38 29 21 28 21 15 10 14 09 044.0 77 58 44 33 61 53 40 30 48 36 26 38 28 20 28 21 14 09 14 09 04

4.2 77 57 43 32 60 52 39 29 47 35 25 37 28 20 28 20 14 09 14 09 044.4 76 56 42 31 60 51 38 28 46 34 24 37 27 19 28 20 14 09 14 08 044.6 76 55 40 30 59 50 37 27 45 33 24 36 26 18 28 20 13 08 14 08 044.8 75 54 39 28 58 49 36 26 45 32 23 36 26 18 28 20 13 08 14 08 045.0 75 53 38 28 58 48 35 25 44 31 22 35 25 17 28 19 13 08 14 08 04

# of fixtures x lamps per fixture

Footcandles = x lumens per lamp x CU x LLF(maintained) area in square feet

maintained footcandles

# of luminaires = desired x area in sq. ft.lamp/fixture x

lumen/lamp x CU x LLF


12/16HOLOPHANE

| THE FUNDAMENTALS OF LIGHTING

1990S: ENERGYCONCERNS AND GREEN LIGHTS

PROGRAM

Holophane offered lighting solutions to companies to mthe EPA requirements and earn rebates.

Z o n a l C a v i t y M e t h o d o f C a l c u l a t i n g I l l u m i n a n c e L e v e l s

Table BMultiplying factors for other than 20 percent effective floor cavity reflectance

% Effectiveceiling cavity 80 70 50 30 10reflectance, cc% Wallreflectance, w 70 50 30 10 70 50 30 10 50 30 10 50 30 10 50 30 10

For 30 per cent effective floor cavity reflectance (20 per cent = 1.00)

Room cavityratio1 1.092 1.082 1.075 1.068 1.077 1.070 1.064 1.059 1.049 1.044 1.040 1.028 1.026 1.023 1.012 1.010 1.0082 1.079 1.066 1.055 1.047 1.068 1.057 1.048 1.039 1.041 1.033 1.027 1.026 1.021 1.017 1.013 1.010 1.0063 1.070 1.054 1 042 1.033 1.061 1.048 1.037 1.028 1.034 1.027 1.020 1.024 1.017 1.012 1.014 1.009 1.0054 1.062 1.045 1.033 1.024 1.055 1.040 1.029 1.021 1.030 1.022 1.015 1.022 1.015 1.010 1.014 1.009 1.0045 1.056 1 038 1.026 1.018 1.050 1.034 1.024 1.015 1.027 1.018 1.012 1.020 1.013 1.008 1.014 1.009 1.0046 1.052 1.033 1.021 1.014 1.047 1.030 1.020 1.012 1.024 1.015 l.009 1.019 1.012 1.006 1.014 1.008 1.0037 1.047 1.029 1.018 1.011 1.043 1.026 1.017 l.009 1.022 1.013 1.007 1.018 1.010 1.005 1.014 1.008 1.0038 1.044 1.026 1.015 1.009 1.040 1.024 1.015 1.007 1.020 1.012 1.006 1.017 1.009 1.004 1.013 1.007 1.0039 1.040 1.024 1.014 1.007 1.037 1.022 1.014 1.006 1.019 1.011 1.005 1.016 1.009 1.004 1.013 1.007 1.00210 1.037 1.022 1.012 1.006 1.034 1.020 1.012 1.005 1.017 1.010 1.004 1.015 1.009 1.003 1.013 1.007 1.002

For 10 per cent effective floor cavity reflectance (20 per cent=1.00)

Room cavityratio1 .923 .929 .935 .940 .933 .939 .943 .948 .956 .960 .963 .973 .976 .979 .989 .991 .9932 .931 .942 .950 .958 .940 .949 .957 .963 .962 .968 .974 .976 .980 .985 .988 .991 .9953 .939 .951 .961 .969 .945 .957 .966 .973 .967 .975 .981 .978 .983 .988 .988 .992 .9964 .944 .958 .969 .978 .950 .963 .973 .980 .972 .980 .986 .980 .986 .991 .987 .992 .996

5 .949 .964 .976 .983 .954 .968 .978 .985 .975 .983 .989 .981 .988 .993 .987 .992 .9976 .953 .969 .980 .986 .958 .972 .982 .989 .977 .985 .992 .982 .989 .995 .987 .993 .9977 .957 .973 .983 .991 .961 .975 .985 .991 .979 .987 .994 .983 .990 .996 .987 .993 .9988 .960 .976 .986 .993 .963 .977 .987 .993 .981 .988 .995 .984 .991 .997 .987 .994 .9989 .963 .978 .987 .994 .965 .979 .989 .994 .983 .990 .996 .985 .992 .998 .988 .994 .99910 .965 .980 .965 .980 .967 .981 .990 .995 .984 .991 .997 .986 .993 .998 .988 .994 .999

Table C: Four-lamp Prismawrap luminaire coefficients of utilization

Spacing Criterion 1.4cc 80% 70% 50% 30% 10%w 70% 50% 30% 10% 70% 50% 30% 10% 50% 30% 10% 50% 30% 10% 50% 30% 10%

0 .78 .78 .78 .78 .75 .75 .75 .75 .70 .70 .70 .66 .66 .66 .62 .62 .621 .72 .69 .67 .64 .69 .67 .65 .63 .63 .61 .59 .59 .58 .56 .56 .55 .532 .66 .62 .58 .55 .64 .60 .56 .53 .56 .54 .51 .53 .51 .49 .50 .48 .473 .61 .55 .51 .47 .59 .54 .50 .46 .51 .47 .44 .48 .45 .43 .46 .43 .414 .57 .50 .45 .41 .55 .48 .44 .40 .46 .42 .39 .44 .40 .38 .41 .39 .365 .52 .45 .39 .35 .50 .43 .38 .35 .41 .37 .34 .39 .36 .33 .37 .34 .326 .48 .40 .35 .31 .47 .39 .34 .31 .37 .33 .30 .36 .32 .29 .34 .31 .287 .45 .36 .31 .27 .43 .35 .30 .27 .34 .29 .26 .32 .28 .25 .31 .27 .258 .41 .33 .27 .23 .40 .32 .27 .23 .30 .26 .23 .29 .25 .22 .28 .24 .229 .38 .29 .24 .20 .36 .28 .23 .20 .27 .23 .20 .26 .22 .19 .25 .21 .1910 .35 .26 .21 .18 .34 .26 .21 .18 .25 .20 .17 .24 .20 .17 .23 .19 .16

RCR

Example:A typical lecture hall is 60' long and 30' wide with a14 ceiling height. Reflectances are: ceiling 80%, walls30%, floor 10%. Four-lamp Prismawrap (coefficientsof utilization shown below) is to be used on 4' stems,and the work plane is 2' above the floor. Find theilluminance level if there are 18 luminaires in the room.

Solutions:(1) Calculate cavity ratios as follows:

(2) In Table A, look up effective cavity reflectances forthese ceiling and floor cavities. cc for the ceiling cavityis determined to be 62%, while fc for the floor cavityis 10%.

(3) Knowing the room cavity ratio (RCR), it is nowpossible to find the coefficient of utilization for thePrismawrap luminaire in a room having an RCR of 2.0and effective reflectances as follows:

cc = 62%; w = 30%; fc = 20%. By interpolationbetween boxed numbers in the table this CU is .55.Note that this CU is for an effective reflectance of 20%while the actual effective reflectance of the floor fc is10%. To correct for this, locate the appropriate multiplierin Table B for the RCR already calculated (2.0). It is .962and is found by interpolating between the boxednumber in Table B for 70% cc, 30% w, and 50% cc,30% w at an RCR of 2.0.

Then:CU final = .55 x .962 = .53

Note that all interpolations only need to be of theapproximate, eyeball type, giving a credible degreeof accuracy to the calculation.

(4) Illuminance level can now be calculated if weknow the number of units to be used and the lamplumen rating.

Check spacing of luminaires.

A possible arrangement for these fixtures is threecolumns of six fixtures spaced ten feet on center ineach direction. The Spacing Criterion is 1.4, makingthe maximum allowable spacing 11.2 feet. The actualspacing is less than the maximum allowable spacing.Therefore, the illumination on the work plane shouldbe uniform.

CCR = 5(4)(30+60) = 1.030 x 60

RCR = 5(8)(30+60) = 2.030 x 60

FCR = 5(2) (30+60) = 0.530 x 60

# of fixtures x lamps/fixture

FC initial = x lumens/lamp x CUarea

FC initial = 18 x 4 x 3150 x .53

60 x 30

FC initial = 67

12


13/16

Calculating average illuminance levels using a utilization curv

The standard Lumen Method formula is also used to calculate average illuminanclevels in an outdoor area when CUs are taken from a utilization curve.

To calculate the number of luminaires needed to produce the desired foot candlesthe following formula is used:

A variation of this formula, which is used mostly for roadway lighting, calculates hofar apart the fixtures must be spaced to produce the nec essary average illuminance

A utilization curve shows the percentage of light which falls onto an area having designated width and an infinite length. This width is expressed on the utilizationcurve in terms of a ratio of the width of the area to the luminaire mounting heig

A CU is found by reading across the bottom axis to this ratio, up until the dasheCU line is intersected, then across to the right hand axis, to read the value of theCU. Separate CUs are given for the area to the street side (forward) and area to thouse side (rear) of the fixture and may be used to find illuminance on the roadwor sidewalk areas, or added to find the total light on the street in the case ofmedian mounted luminaires.

Example:A roadway 24 ft. wide is to be lighted to an average maintained il luminance level o1.0 fc. Holophane Mongoose MV400HPNC6 luminaires are to be used and mounton 30 ft. poles that are set back 36 ft. from the road. Find the spacing required.

See Figure 1

Solution:

The CU is determined by reading from Chart 1 the intersection of the distanceacross/mounting height with the CU and hence horizontally to the CU axis.

The CU for the roadway area only is determined by subtracting the CU of the setbaarea from the CU of the total area of both roadway and setback. The width of thtotal area is 60 feet ( 2.0 M.H.) and the width of the setback is 36 feet (1.2 M.H.From the CU curve (see chart 1 ) we find that the corresponding CUs are .52 and.3. Deducting the second from the first we get a CU of .22. Inserting this CU intothe standard Lumen Method formula results in a spacing of 371 feet.

Lumen Method for Outdoor Calculations

Typic

al

Spacing

Roadwa

yEastB

ound

30 Pole

36

Setback24

Cat. No. MV400HP00NC6 - RE-248

400W Clear HPS/Test No. 49730

8

7

6

5

4

3

2

1

0

.80

.70

.60

.50

.40

.30

.20

.10

05 4 3 2 1 0 1 2 3 4 5

Ratio = Distance Across/Mounting Height

Ratio=DistanceAlong/Mounting

Height

CoefficientofUtilization(DashedCurves)

House Side Street Side

1

2

.2

.5

.001.002

.005

.01

.02

.05

Figure 1

Chart 1

lumens/lamp x lamps/luminaire x

Footcandles =# luminaires x CU x LLF

(maintained) area in square feet

maintained footcandlesdesired x area in sq. ft.# of luminaires =lumens/lamp x lamps/luminaire x CU x LLF

lamp lumens x CU x LLFSpacing =Avg. mtd FC x width of road

lamp lumens x CU x LLFSpacing =Avg. mtd FC x width of road

Spacing =50,000 x .22 x .81

= 371 ft.1.0 x 24

Lumen Method for Outdoor Calculations

2000: THENEWSHAPE OF LIGHTIlluminaire, a retail innovation with unlimitedoptions and accessories, including up/down

lighting options, and the first offer ofa 90% uplight option.


14/16

Point calculations using candlepower data

This method is especially useful in the determination of variation of illuminance levels and the uniformityof illumination provided by a lighting design. It is most frequently used in heavy industrial and designwhere inter-reflections are not a consideration, such as in track lighting and floodlighting.

The point-by-point method accurately computes the illuminance level at any given point in an installationby summing up the illumination contributions to that point from every luminaire individually. It does notaccount for contributions from other sources such asreflection from walls, ceiling, etc. For accuracy, the calculationdistance from source to point of calculation should be at leastfive times the maximum luminaire dimension. Using thephotometric distribution for the unit, we may calculate valuesfor specific points, as follows for horizontal surfaces.

Example:

A single 400W HPS Prismpack luminaire is mounted 26above a work plane. We wish to find the initial horizontalilluminance at a point 15 to one side of the luminaire.

See figure 2.

Solution:

Since

we need to determine the angle and look up the cp at this angle. We also must determine the distance D.

Now we can determine the candlepower of this luminairefrom the cp curve, figure 3, to be 18936 (cp). When lightinga horizontal surface, angle is equal to angle O.The illuminance (E) is then:

When many point calculations must be done by hand, avariation of the basic formula is somewhat more useful.

This version of the formula lets us deal with only the netmounting height of the fixtures and candlepower anglesand eliminates the necessity to calculate each separatedistance D.


2002: LUNAROPTICS SOLUTION FOR

IESNA CUT-OFF

Holophane addresses environmental sky glowand light trespass issues with Lunar Optics.

O u t d o o r C a l c u l a t i o n s a n d E x a m p l e s

Luminaire

D

Elevation

Luminaire Calculation Point+Plan

PHOTOMETRIC TEST REPORTHOLOPHANE CORPORATIONHOLOPHANE RESEARCH & DEVELOPMENT CENTERNEWARK, OHIO 43055

DISTRIBUTION DATA

ZONAL

LUMENS

ZONAL

DEGREES

TOTAL

EFFIC.

OUTPUT DATA

TESTEDBY CERTIFIED BY

TEST NO.

030 30

6060

90 90

120 120180150 150

42181

PP5K400HP00XXJ39

Set Position

400W Clear HPS

400

25 FT.

50000

E-18

1.4

TEST OF HOLOPHANE

POSITION OF LAMP

LAMP

WATTS

TEST DISTANCE

LUMENS

BULB TYPE

S.C.

0 16880

5 16774 1601

10 17611

15 19672 5576

20 20262

25 20286 9389

30 18936

3 5 1 69 25 1 063 2

40 14199

45 10411 8063

50 6367

55 3256 2921

60 1296

65 732 727

70 574

75 417 441

80 301

85 219 239

90 57

95 35 38

105 46 48

115 64 63

125 77 69

135 141 109

145 574 360

155 867 402

165 14 4

175 18 2

180 7

0-30

30-60

60-90

0-90

90-180

0-180

VERTICAL

ANGLE

CANDLE

POWER

ZONAL

LUMENS

16567

21616

1407

39591

1096

40686

33.1

43.2

2.8

79.2

2.2

81.4

2500 CD/DIV

Figure 3

Figure 2

fc =candlepower x cos O

D2

E =18936 x cos 30

= 18.2 fc(30)2

fc =Candlepower x (cos O)3

h2

Since D2 = a2 + h2D2 = (15)2 + (26)2D = 30 feet

Tangent = ah

= arc tangent 1526

= 30

Point calculations using theisofootcandle chart

The isofootcandle chart can also be used to findthe illuminance at a specific point. It is found bydefining the horizontal distance from the fixture

to that point in terms of a ratio of distance tomounting height, then looking up that ratio onthe chart. If the actual mounting height of thefixture is different than the isofootcandle chartsassumed mounting height, a correction factormust be applied using the following formula:

Example:

Using the same layout and fixtures as were usedin the example on page 13, determine theilluminance level, between the two units, on thefar side of the road using Chart 1.

Solution:

From either fixture, point A is 60 feet to thestreet side (2.0 M.H.) and 140 feet down thestreet (4.7 M.H.). Looking at the isofootcandlecurve, we find that the illuminance value at thatpoint is .30 fc. This is the contribution from oneluminaire and should be summed with othercontributions for total footcandles. Since theisofootcandle chart mounting height is thesame as our mounting height, no furthercorrection is necessary.

Computer programsPoint-by-point calculations can be timeconsuming. Our lighting software, Visual, canperform such calculations for many analysispoints and luminaires in a fraction of the timenecessary to do the same calculations by hand.

correction factor = chart MH2

actual MH2

14

fc =candlepower x cos O

D2


15/16

The Professional Edition of Visual 2.3 is a collection of lighting calculation tools designed fomore demanding interior and exterior applications. The Professional Edition provides the abito model complex architecture, including sloped or angled surfaces, domes, barrel vaults, anobstructions. A unique approach has been taken with regard to the 3-D interface to create more intuitive and lighting-design-friendly manner of operation. As a result, working in 3-D easy, fast, and informative. It is a unique and powerful extension of your own design procesThe Professional Edition will read files created using the Basic Edition. Flexible and intuitive, enables you to analyze and modify lighting designs faster than ever before, empowering yoto spend less time building projects, and more time designing.

True 3D Environment

I Visual 2.3 provides the user with a true three-dimensional workspace, allowing the useto design and view lighting environments from any angle.

I It allows the user to work dynamically in any of the standard planes (X-Y, X-Z, or Y-Z).This makes building complex spaces easy and efficient.

Non-Orthogonal Surfaces

I Visual 2.3 will model complex geometries accurately and in a time-efficient

manner, including sloped ceilings, domes, and other curved surfaces.Luminaire Schedules

I Visual 2.3 allows an unlimited number of luminaire types.

I It provides a library of standard luminaire symbols and includes a symbol editor.Default information can be enhanced or changed as needed.

Flexible Calculation Grids

I Calculation grids can be added in any shape or orientation and on any surface desired

I Masking of grids is accomplished either in blocks or individually. The points may beoriented in any direction.

Iso-Illuminance Curves

I Optional iso-illuminance curves for any luminaire or pole configuration assist in

placement.Obstructions

I Both interior and exterior designs may include obstructions of any shape, orientationor reflectance.

I Calculation grids are easily placed on any surface of an obstruction.

I There is no limit to the number of obstructions allowed.

Presentation Quality Results

I The results can be printed to any size media, from an 8.5"x 11" page to a full E-sizedplotted page.

I The powerful print editor allows for completely customized pages, both in contentand in appearance.

Additional Features

I Visual 2.3 follows standard Windows and CAD interface protocols, making fora short learning curve.

I Both DXF and DWG format drawing files can be imported and exported.

I A Lumen Method tool is provided for the quick design and analysis of simple lightinglayouts where uniform illuminance is the objective. The streamlined calculation enginecomputes even the most complicated designs in only a fraction of the time.

Visual 2.3 Professional Edition

Visual 2.3

2005: ISD SUPERGLASS REFLECTOR DEVELOPED

A revolutionary, scientific advancement in optical design


16/16

Achieving the required illuminance level does notnecessarily ensure good lighting quality. The qualityas well as the quantity of illuminance is importantin producing a comfortable, productive, aesthetically

pleasing lighted environment. The quality of thelighting system includes, but is not limited to,aspects of lighting such as proper color, gooduniformity, proper room surface luminances,adequate brightness control and minimal glare.

Research has suggested that the lighting system canaffect impressions of visual clarity, spaciousness andpleasantness. These feelings occur in spaces thatare uniformly lighted with emphasis on higherluminances on room surfaces.

The improved user satisfaction from such spaces mayor may not have any effect on worker performance.However, given two lighting systems with equallifetime costs, lighting systems which provideimproved worker satisfaction should be considered.

User satisfaction is often considered in the design ofoffices and commercial spaces, but ignored inindustrial spaces. However, the industrial en vironmentshould be designed to provide a high-quality visualenvironment, yielding improved worker satisfactionand possibly improved productivity as well. This canbe accomplished by using lighting systems whichproduce the proper luminance on ceilings and walls.

The photo on this page illustrates two lighting systemsin the same industrial environment. Both lightingsystems provide the same quantity of horizontalilluminance on the work plane. The system on theright provides little uplight, resulting in the typicalcavern effect associated with industrial spaces.

The system on the left provides uplight and improvesthe luminance of the ceiling and vertical surfaces.This system can provide workers with a feeling ofincreased spaciousness. The uplight component alsotends to improve work plane illuminance uniformity,reducing shadows and possibly yielding improvedfeelings of visual clarity.

Any lighting design should consider the impressionsof the user of the space. The photograph indicatesthat even an industrial environment can be improvedwith the hope of providing better working conditionsand improved satisfaction and productivity for theworker.

Prismatic Glass (left) Aluminum Reflector (right)

Acuity Brands Lighting, Inc.

214 Oakwood Ave., Newark, OH 43055 /Holophane Canada, Inc. 9040 Leslie Street, Suite208, Richmond Hill, ON L4B 3M4 / HolophaneEurope Limited, Bond Ave., Milton Keynes MK11JG, England / Holophane, S.A. de C.V., ApartadoPostal No. 986, Naucalpan de Juarez, 53000 Edo.de Mexico

Contact your local Holophane factory salesrepresentative for application assistance, andcomputer-aided design and cost studies. For informationon other Holophane products and systems, call theInside Sales Service Department at 740-345-9631.In Canada call 905-707-5830 or fax 905-707-5695.

Limited Warranty and Limitation of LiabilityRefer to the Holophane limited material warrantyand limitation of liability on this product, which arepublished in the Terms and Conditions section ofthe current Buyers Guide, and is available from yourlocal Holophane sales representative.

Visit our web site at ww.holophane.com

Lighting Quality

Luminaires may utilize fluorescent or high intensity discharge sources that contain smallamounts of mercury. New disposal labeling for these lamps includes the mercury identifiershown below to indicate that the lamp contains mercury and should be disposed of inaccordance with local requirements.

Information sources regarding lamp recycling and disposal are included on thepackaging of most mercury-containing lamps and also can be located atwww.lamprecycle.org.

Documents

Holophane Lighting Fundamentals