AUTISM SPECTRUM DISORDER (ASD) Education Environment

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AUTISM SPECTRUM DISORDER (ASD)

EDUCATION ENVIRONMENT Lighting Design Concerns and Recommendations

HUSSEIN MOHAMED NYCSCA

March 2014

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Table of Contents

1- INTRODUCTION ……………………………………………………………………………4

2- OCCUPANT INPUT: SURVEY RESULTS ……………………………………………....5

2.1- Main Concerns ....………………………………………………………….…………5

2.2- Design Consideration ………………………………………………………………..5

3- DETAILED DESCRIPTION OF MAIN CONCERNS ...………………………………….6

3.1- Light flicker and audible hum ………………………………………………………. 6

3.2- Uneven distribution of light in a given space ……………………………………...7

3.3- Direct line of sight to the source of light ……………………………………………8

3.4- Contrasting shadows on the wall surface ………………………………………….9

3.5- Distracting bright spots and glare ……………………………………………..…..10

3.6- Inconsistent color temperatures of the lamps ……………………………………12

4- CURRENT LIGHTING DESIGN …………………………………………………………13

4.1- Classroom ……………………………………………………………………….…..14

4.1.1- Classroom Fixture …………………………………………………………..14

4.1.2- Classroom Layout …………………………………………………………..15

4.2- Corridors, Offices and Toilets ……………………………………………………...17

4.2.1- Corridors, Toilets and Lockers Fixtures …………………………………17

4.2.2- Office Fixture ………………………………………………………………...17

4.3- Stairs …………………………………………………………………………………18

4.4- Assembly Spaces ………………………………………………………..…………18

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5- PROPOSED LIGHTING DESIGN ……………………………………………………….19

5.1- Classroom ……………………………………………………………………………20

5.1.1- Classroom Proposed Lighting Fixture …………………………………….20

5.1.2- Classroom Proposed Lighting Layout …………………………………….21

5.1.3- Three Rows vs. Two Rows .............................………………………….24

5.2- Classroom Lighting Control ……………………………….……………………….29

5.2.1- Current Classroom Lighting Control ………………………………………29

5.2.2- Classroom Proposed Lighting Control ……………………………………30

5.2.3- Classroom Control by Lutron System …………………………………….32

5.2.4- Classroom Control by Hubbell System ………………………….………..34

5.3- Corridor and Offices ………………………………………………………………...35

5.3.1- Corridor Proposed Lighting Fixture ……………………………………….36

5.3.2- Corridor Proposed Lighting Layout ……………………………………….38

5.3.3- Offices Proposed Fixture …………………………………………………..47

6- AUTOMATIC SHADE SOLUTION ……………………………………………………...49

7- DESIGNER CONSIDERATIONS ……………………………………………………….50

8- APPENDEX ..……………………………………………………………………………..52

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1- INTRODUCTION

Students with ASD face many struggles and challenges in educational environments and classrooms. Classroom and other educational facilities are designed with the intention to be bright and display a variety of objects and information to encourage interaction and learning. These stimuli can become overwhelming to a student with ASD who has difficulty focusing their attention. They may focus their attention to extraneous sights and sounds and be unable to engage in classroom activities and instruction.

Many traditional schools built in previous decades or even on conservative

budgets do not accommodate students by providing special needs classrooms. Most classrooms are designed based on economics and uniformity. There is a balance between efficient and cost effective classroom design and design that focuses on providing for the unique needs of special needs students and students with ASD. Many students with ASD are educated in standard classroom environments with the rest of their classmates and peers. Most students with mild cases of ASD are able to keep up with the curriculum but can find themselves struggling and lose focus when forced to ignore distractions. This fight to overlook distracting light and extraneous noise leads to a greater effort in learning the materials presented in class.

In the educational classrooms, fluorescent lighting is a significant source of

extraneous stimuli that not only a source of annoyance but can also trigger common symptoms of ASD. Fluorescent fixtures economically provide an acceptable uniformity and quality of illumination, but also have disadvantages that can aggravate symptoms in students with ASD.

This report will address the education environment and student considerations in

order to develop parameters and design practices that will assist new lighting designers.

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2- OCCUPANT INPUT: SURVEY RESULTS To achieve the best design in theory as well as practical usability, it is important

to understand the needs and concerns of the occupants. Teachers and special needs coordinators made significant contributions to the study by expressing the concerns and needs of the instructors and students.

2.1- Main Concerns

The most significant concerns that were addressed in the lighting design surveys were the light level of the space, noise from the fixtures, and user control. Students were bothered and stressed by high light levels, hot spots created by pools of light, shadows, and reflected glare from wall or desk surfaces. The following six points highlight the main concerns which are followed by a detailed description. 1. Light flicker and audible hum 2. Uneven distribution of light in a given space 3. Direct line of sight to the source of light 4. Contrasting shadows on the wall surface 5. Distracting bright spots and glare 6. Inconsistent color temperatures of the lamps

2.2- Design Considerations

In order to create the most user-friendly and comfortable learning environment based on these needs, the following design considerations should be taken into account 1. All light fixtures should be dimmable so that a comfortable light level can

be set by the teacher for each space. 2. High ceiling to allow the light to be distributed and reduce most direct lines

of sight of the lamp. 3. Special consideration to be given to materials and finishes in the space to

reduce reflective glare. 4. Room size should be taken into consideration to eliminate light to create

bright scalloped patterns and contrasting shadows on the wall surface.

In order to address the main concerns, the architects and designers work

together to successfully address and work solutions to the restrictive criteria.

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3- Detailed Description of Main Concerns:

3.1- Light flicker and audible hum. There are many types of ballasts for fluorescent fixtures that vary in

frequencies. It is these operating frequencies that ultimately produce the flicker and the hum that are generated by the alternating current (AC). Because of the behavioral problems and frustration triggered by the fluorescent fixtures in the general education classrooms, instructors have tried to amend the problem by providing specific area in the classroom for students with ASD to independently work.

Magnetically ballasted T12 fluorescent with flicker

LED source with flicker – note white vertical lines in photo

The flickering light or hum is in equal competition with the information being presented by the instructor. This results in an overflow of information and creates a stressful learning environment for students with ASD.

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3.2- Uneven distribution of light in a given space Vertical illumination, that is light levels measured on wall surfaces, must

balance in contrast ratio with illumination levels on the work surface to reduce fatigue and discomfort when looking up from a task. The IESNA recommends that the light levels on vertical surfaces be no greater than five times and no less than 1/3rd the light levels on the work surface. Vertical surfaces also need to be evaluated in the design. Hot spots of light can occur on wall surfaces as the result of light cut-off from the fixture.

Recessed fluorescent 2 x 4 troffer fixtures can create hot spots on vertical surfaces near the ceiling.

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3.3- Direct line of sight to the source of light The survey response said "Students will turn off the lights indicating they

are bothering them and causing them to be upset." There are no lenses or coverings to shield the lamps from direct sight. The bright light output makes it difficult for the students to "sit, concentrate, and learn." The light intensity creates a difficult environment for the students to concentrate and focus on learning material.

Indirect distribution of light allows for the source to be hidden from direct view and allows for the light to diffuse on the reflecting surface. High ceilings are best because they allow space for the light from indirect fixtures to have wider distributions when light reaches the working plane.

Teacher at school PS 120 uses a cloth to minimize direct line of sight of artificial light.

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3.4- Contrasting shadows on the wall surface. For children with autism, shadows obscured recognition of objects, so that

the children were really not able to attend to the objects but were instead distracted by shadows. It may be most effective then, in teaching children with autism, to choose a space with careful lighting and therefore the children will be less distracted by shadows.( Children with Autism Distracted by Shadows By Jody Smith )

Lights created bright scalloped patterns and contrasting shadows on the wall surface.

http://www.empowher.com/autism/content/children-autism-distracted-shadows

http://www.empowher.com/user/2171

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3.5- Distracting bright spots and glare Reflection from the lighting on the glossy laminate hindered the students’

ability to see their work, caused them to squint, and reduced their independence and engagement in activities as staff were frequently having to reposition work to reduce glare. Finishes can affect the overall brightness of the space and could have problems with glare.

Hot spots and glare are reduced slightly with the use of indirect/direct

suspended fluorescent fixtures, however fully indirect will work better. Glazing should be located high on the walls. Shades should be used to control light levels and glare. Photo sensors shall integrate electric light fixtures and provide dimming. Use finishes with darker and muted colors to soften the light and eliminate glare off surfaces. Select surfaces with a lower reflectance value.

The reflective flooring material can create glare and hot spots. This problem is avoided by dimming and adjusting the light level for the comfort of the user.

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PS 177X west wing classroom with light blue wall color has less glare which creates a more comfortable learning space.

The same above classroom (PS 177X). All the white walls produce glare on the surface of the floor.

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3.6- Consistent Color Temperatures of the Lamps. Fluorescent lamps can vary in color temperature and can also create visual

distractions and inconsistency. As a lamp reaches the end of the estimated lamp life, the color temperature can differ from when it was originally installed. As lamps are replaced as needed in various fixtures, the color temperature can vary in the fixtures creating a distracting spectrum.

Graphic of color temperature of common light sources.

Shift in color temperature in old linear fluorescent lamp can cause uneven lighting distribution in the space

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4- Current lighting Design

Fluorescent fixtures are traditionally and still currently the most popular fixture in New York City Schools because it is able to fulfill the recommendations for quality and efficiency, while still maintaining a reasonable budget. These fixtures provide efficient general illumination while maintaining an acceptable color rendering index (CRI). CRI refers to the accuracy the light emitted from the source compares to the perfect color proportions of the visual spectrum; day light has a CRI of 100, which is the highest value.

Although fluorescent fixtures are strongly encouraged for traditional classroom lighting designs, they are not recommended for autism classrooms. Fluorescent sources and fixtures have made advancements to reduce noise and flicker and other disadvantages in order to improve their overall performance and be more versatile in applications. Even with improvements to these fixtures, the brightness, flicker and hum are still strongly noticed by most students with ASD.

Fluorescent lamp construction and operation is the greatest source of

flickering. Students with ASD are able to perceive the cyclical flickering when other students may be unaffected. Ballasts that function with fluorescent lamps create the audible humming noise which is a distracting and frustrating stimuli to students with ASD. Even with improvements to ballast construction and operation and the common use of high frequency ballasts, it is not encouraged that any type of fluorescent fixture be installed in special needs or ASD classrooms.

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4.1- Classroom Most classroom type spaces constructed are similar in finishes and fixtures.

Direct/indirect, ceiling pendant fluorescent luminaires for typical classrooms measuring approximately 29’ X 26’, lighting usually consist of two (2) rows of direct /indirect with lighting distribution between 70-80% up and 20-30% down.

4.1.1- Classroom fixture

Direct/indirect lighting fixture with 2T8 fluorescent lamps supported with single air-craft cable.

4.1.2- Classroom layout Classroom lighting layout consists of two (2) rows of direct

/indirect Fixtures mounted such that the bottom of the luminaires is at 8’-0” in Early Childhood Centers and Primary Schools and 8’-6” in Intermediate Schools and High Schools, with the optimum fixture to ceiling distance ranging from 14” to 24”.

Lighting controlled by one ceiling mounted vacancy sensor and two switches located by the classroom entrance door. Each switch shall controls one lamp in each fixture on the same side of each row.

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Comparison between two regular size classrooms with standard indirect/direct fixture CR301: LED 48W fixture

CR304: linear fluorescent 2T8 fixture

Description # Luminaires Total Watts Area Density

Power Density CR301 10 476.0 W 694.1 ft² 0.7 W/ft²

power density CR304 10 580.0 W 709.6 ft² 0.8 W/ft²

Power Statistics

Description Symbol Avg Max Min Max/Min Avg/Min Avg/Max

classroom301 42.0 fc 60.6 fc 20.5 fc 3.0:1 2.0:1 0.7:1

classroom304 42.9 fc 63.1 fc 18.5 fc 3.4:1 2.3:1 0.7:1

Statistics

Symbol Label Quantity Manufacturer Catalog Number Lamp Number

Lamps

Lumens Per

Lamp

Wattage

A 10 PINNACLE

ARCHITECTURA

L LIGHTING

GLS90 SCB28 232 TWO

HORIZONTAL 32

WATT T8

LINEAR

FLUORESCENT

LAMPS RATED

AT 2800

LUMENS EACH.

2 2800 58

D 10 PINNACLE

ARCHITECTURA

L LIGHTING

LC6A35-40HO-4-

AC48G1-120-1C-W

TWO HUNDRED

FORTY WHITE

LIGHT EMITTING

DIODES (LEDS),

AIMED 10-

DEGREES

ABOVE THE

HORIZON.

240 15.93622 47.6

Luminaire Schedule

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4.2- Corridors, offices, and toilets Fluorescent tube lamps in recessed troffers are the most common fixtures

seen in educational facilities due to its efficiency and low-cost. Recessed troffers are typically measured in increments of one foot and are designed to fit conveniently into acoustical ceiling grids. The majority of the fixture housing is recessed into the ceiling plenum with the bottom edge of the fixture flush with the ceiling tiles. These fixtures house between one and four fluorescent tube lamps (T-lamps). Reflectors built into the housing will direct light down to the space while louvers or lens coverings on the bottom face of the fixture will distribute and diffuse the light. Shown below are a sketch and cross-section of typical recessed troffers.

4.2.1- Corridors, toilets and lockers fixture

Recessed 2'x4' fluorescent luminaires, with prismatic lens 2, 3 or 4 lamps

4.2.2- Offices fixture Recessed 2'x4' fluorescent luminaires, parabolic with 18 cells

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4.3- Stairs:

Most of schools use 4' fluorescent luminaires, wrap around, with vandal resistant lens. Usually fixture housing built from heavy-duty, 16-gauge one-piece cold-rolled steel, corner or surface-mounted.

4.4- Assembly spaces (Auditorium, Gym) and main lobby: The lighting designer may select luminaires suited to the aesthetic of the

spaces. Recently built schools have many LED installed in those areas.

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5- Proposed Lighting Design Lighting for the space is achieved using dimmable LED fixtures with 100% up-

light suspended to a high ceiling in area of instructions and direct LED lighting fixture with white defused lens in none instructions area. Each individual room is equipped with a separate control for on/off and dimming. Each of the instruction spaces is controlled separately by a single slide dimmer switch.

Because of the noise concerns expressed when using fluorescent ballasts, no

ballasts will be used to control the light fixtures in the Autism wing. When all lamps are on at full capacity, the light levels are an approximately 35 foot candle which is lower than the forty foot candles recommended by SCA for regular classrooms. The light levels recommended by the IESNA are an average of 30-50 foot candles (fc) for reading and writing tasks. Glare is a concern when higher light levels are required, especially in environments with reflective surfaces such as desks or whiteboards.

Day light from the windows varied the light readings in the larger Sensory

classroom depending on time of day and if there was a cloud cover. Ceiling

mount daylight sensor saves energy by dimming or turning off electric lighting

when sufficient daylight is available. The sensor adjusts the lights to take

advantage of daylight and keep a steady light level.

The high windows achieve a high amount of daylight which has shown to provide emotional and mental benefits in classroom environments. Because of the height of the windows and operating hours of the classroom, direct glare has not been a concern in the space. Automatic shades are controlled by the teachers to increase the level of control and comfort to the students.

Finishes and materials in a space can be a commonly overlooked design

element in lighting design. For the Autism wing classroom finishes, materials and colors should be a high priority and integrated well with the lights. Soft, muted colors are to be used on the walls and neutral, calm blues are to be used in the tiled and carpeted areas.

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5.1- Classroom

5.1.1- Classroom Proposed Lighting Fixture

The proposed lighting fixture will have the following features: 1. Round or rectangular with curved profile for pleasant, modern look. 2. Fully indirect LED lighting fixture with 100% up-light 3. 30K color temperature with minimum 1200 lumens/ft. for warmer

lighting environment 4. Pendant mounted with single aircraft cable 5. Flicker free Dimmable driver with 0-10v dimming option 6. Suitable for installation in continuous rows 7. Adjustable single aircraft cable mounts on 4'-0” and 8'-0” centers 8. Wide distribution to eliminate hot spots while increasing uniformity

across the ceiling.

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Pendant mounted with single aircraft cable

Fully indirect with wide distribution

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5.1.2- Classroom Proposed Lighting Layout Proposed Classroom lighting layout consists of: 1. Three rows of lighting fixtures with maximum distance 8’ to 10’

between rows 2. Pendant mounted 2 feet under furnished ceiling 3. Rows are centered in the room and located two to three feet away from

the walls for better distribution and less hot spots in the walls. 4. One dimming switch installed by the entry door 5. Vacancy sensor for automatic shut-off as required by code 6. Daylight sensor to adjust artificial light based on the amount of daylight

in a room

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Rendering view for proposed ASD Classroom

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5.1.1- Three Rows VS. Two Rows

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The three rows classroom shows brighter lighting space

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No hot spot created at the wall surface for the three rows layout which is clearly noticeable in the two rows layout.

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CR42-FC LEVEL 37.3 fc 49.9 fc 24.9 fc 2.0:1 1.5:1 0.7:1

wall 29.1 fc 121.3 fc 14.2 fc 8.5:1 2.0:1 0.2:1

Statistics

Poor distribution at floor and ceiling surfaces and hot spots at wall surface

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CR44-FC LEVEL 40.9 fc 55.9 fc 23.9 fc 2.3:1 1.7:1 0.7:1

CR44-WALL FC 27.0 fc 41.9 fc 15.4 fc 2.7:1 1.8:1 0.6:1

Statistics

Even distribution in floor and ceiling surfaces and no hot spots at wall surface

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5.2- Classroom Lighting Control

5.2.1- Current Classroom Lighting Control

The following schematic wiring diagram presents typical classroom lighting control with a single vacancy sensor, two low

voltage switches, and one power pack

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5.2.2- Classroom Proposed Lighting Control

The proposed classroom lighting control is made of three major items:

1. Vacancy sensor

Dual technology ceiling-mount

occupancy sensor in vacancy mode

Corresponding zones will turn off

when the occupancy sensor is in

the unoccupied state (open).

2. Daylight Sensor

The sensor will work with LED

Dimming drivers and control

modules, to implement daylight

harvesting.

The sensor will maintain a specific

light level in the space, and it will

allow the control system to

automatically dim the lights when

the available daylight is high and

brighten the lights when the

available daylight is low.

3. Dimming switch

Turn the classroom lighting fixtures On and Off

Raise and lower light levels

Recall favorite light levels

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Classroom layout with fixtures and controls

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5.2.3- Classroom Control by Lutron System

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5.2.4- Classroom Control by Hubbell System

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5.3- Corridors and Offices.

The recessed fluorescent troffer is everywhere in American commercial

spaces, with 1×4, 2×2, and 2×4 troffers comprising more than 50% of the

luminaires installed in commercial applications and using more than 87

Terawatt-hours (TWh) of electrical energy per year. Consequently, energy-

efficiency improvements to this category of luminaire through the use of LED

technology can potentially yield significant energy and environmental benefits.

This report describes an exploration of troffer lighting as used in office and

classroom spaces.

Dedicated LED troffers are ready to compete with fluorescent troffers in

terms of efficacy (lumens per watt [lm/W]), and in many lighting quality issues

such as glare, light distribution, visual appearance, and color quality.

The architectural lighting industry is very familiar with fluorescent

troffers, but now that LED options are available, a more complex set of

choices has developed. Designer must evaluate how well LED products

perform compared to conventional fluorescent troffers (and each other),

which involves a wide range of criteria—much of which extends beyond the

scope of LM-79-08 testing. Some important evaluation criteria include:

Light output (lumens). Photometric distribution, direct glare, reflected glare, overhead glare,

uniformity of light on task surface, and spacing criteria. Color quality including color rendering and color appearance. Flicker, at full output and when dimmed. Dimming performance including the smoothness and minimum light output. Ease of installation Energy efficiency, or specifically, the total luminaire efficacy and lighting

power density of a typical installation.

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5.3.1- Corridor Proposed Lighting Fixture

LED Recessed Troffer

Upper reflector 98% efficient reflects light out of the fixture.

LED arrays Highly efficacious global LED platform array 3000K color temperatures

Door frame Provides easy access to the inside of the fixture

Optics Single piece extruded diffuse white lens. Controls light to create a less glare distribution. Eliminates visibility of individual LED’s

LED driver Multiple lumen packages, 0-10V dimming, battery pack options, and accessible from below for easy maintenance.

Perimeter reflectors Highly efficient microcellular PET material mixes light within the optical cavity.

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Flat panal with decorative trim

Indirect light bar LED

Single basket LED

Two baskets LED

Opal lens LED

There is a wide range of LED product-qualities which shall be reflected in the design: color, efficacy, light output, appearance, glare, and flicker. Many of these factors cannot be evaluated from a manufacturer’s specification sheet, so it is necessary for the designer to see and compare products in person, and in mockups.

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5.3.2- Corridor Proposed Lighting Layout

Case study: autistic suite Corridor at School PS 335 Queens

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Corridor with four deferent lighting arrangements

LAYOUT #1: 14’ BETWEEN (2X4) 59W FLUORESCENT FIXTURES

LAYOUT #2: 14’ BETWEEN (2X4) 49W LED FIXTURES



(1X4) LED FIXTURES (2X2) LED FIXTURES 2X4 (2X4) LED FIXTURES (2X4) FLUORESCENT FIXTURES

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Symbol Label QTY Catalog

Number

Description Lamp Number

Lamps

Lumens

per Lamp

LLF Wattage

2T8 12 LU24A-

2T8

Lucen 2x4, Architectural Recessed

fluorescent fixture

2 - 32W T8 2 2900 0.95 59

LED24 12 LU24A-

4047

2X4, FABRICATED METAL

HOUSING WITH WHITE PAINTED

INTERIOR FINISH, 2-PIECE FORMED

WHITE PAINTED METAL

REFLECTOR, 4 WHITE CIRCUIT

BOARDS EACH WITH 36 LEDS,

EXTRUDED TRANSLUCENT

FROSTED ACRYLIC DIFFUSER IN

FABRICATED WHITE PAINTED

METAL FRAME.

ONE HUNDRED FORTY-

FOUR WHITE MULTI-

CHIP LIGHT EMITTING

DIODES (LEDS),

VERTICAL BASE-UP

POSITION.

144 30.8794 0.95 48.8

LED22 17 LU22A-

4032



INTERIOR FINISH, 2 WHITE CIRCUIT

BOARDS EACH WITH 36 LEDS.

SEVENTY-TWO WHITE

MULTI-CHIP LIGHT

EMITTING DIODES

(LEDS), VERTICAL BASE-

UP POSITION.

72 41.5663 0.95 33

LED14 17 LU14A-

4030



INTERIOR FINISH, 4 WHITE CIRCUIT

BOARDS EACH WITH 36 LEDS.

ONE HUNDRED FORTY-

FOUR WHITE MULTI-

CHIP LIGHT EMITTING

DIODES (LEDS),

VERTICAL BASE-UP

144 20.0543 0.95 32.4

Luminaire Schedule


CORRIDOR LPD-14' BETWEEN (2X4)

2T8 FIXTURES

12 708.0 W 1318.9 ft² 0.5 W/ft²


LED FIXTURES

12 585.6 W 1318.9 ft² 0.4 W/ft²


LED FIXTURES

17 561.0 W 1318.9 ft² 0.4 W/ft²


LED FIXTURES

17 550.8 W 1318.9 ft² 0.4 W/ft²

Power Statistics


CORRIDOR FC-14' BETWEEN (2X4)

2T8 FIXTURES

23.9 fc 32.3 fc 13.8 fc 2.3:1 1.7:1 0.7:1


LED FIXTURES

23.7 fc 31.4 fc 11.5 fc 2.7:1 2.1:1 0.8:1


LED FIXTURES

22.5 fc 28.2 fc 15.2 fc 1.9:1 1.5:1 0.8:1


LED FIXTURES

22.5 fc 31.2 fc 9.8 fc 3.2:1 2.3:1 0.7:1

Statistics

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Layout #1: 14’ between (2X4) recessed fluorescent fixture with 2T8 (Current SCA standard layout for corridors)

Brightness

Illuminance Brightness

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Layout #2: 14’ between (2X4) recessed 49W LED fixture

Brightness


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Brightness


44


Brightness


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Current SCA layout with LED fixtures 10’ apart



33W LED FIXTURES

21.2 fc 25.1 fc 9.4 fc 2.7:1 2.3:1 0.8:1

Statistics

Symbol Label Quantity Manufacturer Catalog

Number

Description Lamp F

i

Lumens

Per

Light

Loss

Wattage

LED24 16 PINNACLE

ARCHITECTURA

L LIGHTING

LU24A-4032 FABRICATED METAL HOUSING WITH WHITE

PAINTED INTERIOR FINISH, 4 WHITE CIRCUIT

BOARDS EACH WITH 36 LEDS, EXTRUDED

TRANSLUCENT FROSTED ACRYLIC DIFFUSER IN

FABRICATED WHITE PAINTED METAL FRAME.

DIFFUSER FROSTED BOTH SIDES.

ONE HUNDRED FORTY-

FOUR WHITE MULTI-CHIP

LIGHT EMITTING DIODES

(LEDS), VERTICAL BASE-

UP POSITION.

L

U

2

4

A

-

20.3051 0.95 32.4

Luminaire Schedule


CORRIDOR LPD- 10' BETWEEN (2X4)

33W LED FIXTURES

16 518.4 W 1318.9 ft² 0.4 W/ft²

Power Statistics

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Brightness

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5.3.3- Office Proposed Fixture

LED technology allows recessed lighting fixture to have the best possible combination of lighting control

and brightness – with efficiencies that are almost 20% higher than other recessed lighting products.

CCuurrrreenntt PPrrooppoosseedd

Typical parabolics create harsh shadows, dark cave-like environments, and glare.

Batwing distribution luminaires provide excellent glare control, distribution, increased brightness on the walls, and softer shadows.

Batwing distribution

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6- Automatic Shade Solution

Automatic control switch which looks similar to the lighting dimming switch

Helps the students stay focused

Eliminates glare from the desk surface and reduces strain on students' eyes.

Shades will filter the sun’s harsh rays and provide the optimal light level for the class

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7- DESIGNER CONSIDERATIONS

The highest consideration and priority is to create a comforting, calm, and peaceful environment for special needs students. The table below summarizes important considerations and recommendations for ASD classroom design.

ITEM DESIGN CONSIDERATIONS DESIGN RECOMMENDATIONS

Physical Layout of

Space

Most special needs teachers and coordinators recommended classrooms with smaller closed classroom areas and short hallways.

Provide lighting and controls for each logically separated area of use. High ceilings minimum of 10 and maximum of 13' are optimal.

Room Finishes

Finishes can affect the overall brightness of the space and could have problems with glare.

Use finishes with darker and muted colors to soften the light and eliminate glare off surfaces. Select surfaces with a lower reflectance value.

Light Source Direct line of sight to the lamp should be avoided. Even light distribution to reduce shadows.

Fully indirect light should be used. Pendant mounted fixtures installed 2’ under furnished ceiling. Other direct lighting fixtures should have a white defused lens.

Lamps High CRI of 85 or greater, warm color temperature of 3000-3500K.

Use LED Fixtures with 90 CRI and 3000k color temperature.

Light Fixtures Flicker decreases with an increase in lamp operating frequency. Noise also decreases in electronic ballast. However, the flicker and noise both will still exists in fluorescent lights.

LED Fixtures do not require a ballast for operation and therefore eliminate the problems with noise. Flicker free LED driver should be used in case of dimming

Light Levels Students reported visual brightness as a source of anxiety and frustration. Lower light levels best suit their needs.

Reduce light levels to an average of 25-35 fc opposed to the traditional levels of 30-50 fc.

Lighting Controls

Light levels need to be adjusted to the intended use of the classroom or the comfort level of the students.

Dimming all lamps equally will lower the light levels and still provide even light distribution. Controls should be available for each lighting area.

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ITEM DESIGN CONSIDERATIONS DESIGN RECOMMENDATIONS

Day-lighting Provides quality light into the space and a comforting connection to the outdoor environment.

Glazing should be located high on the walls. Shades should be used to control light levels and glare. Daylight sensors shall integrate electric light fixtures and provide dimming.

Energy Energy standards limit the w/ft2

allowed. The more efficient the lamp and fixture assembly the better.

LED lighting is the most efficient source of light in the market. Calculations based on building-area method can achieve as low as 0.8 w/ft2 by using LED lighting.

Contrast Ratio Contrast ratios should meet the recommendations prescribed in the IESNA Handbook.

From the working surface to a vertical surface in the direct line of sight, the contrast ratio should be limited to a difference of 1 to 3. A ratio of 1 to 5 is acceptable for vertical surfaces but not immediately in the line of sight.

Maintenance Lamps with longer lamp life and less lumen depreciation and accessible fixtures

LED lamp life ranges 40,000 -60,000 hrs which will not require frequent replacement. Use accessible housing LED fixtures with replaceable LED boards.

Vertical Illumination

Vertical surfaces should be as evenly illuminated as possible with limited shadowing and a contrast

Select fixtures with a wider distribution for indirect light source and controlled distribution for direct light source to avoid sharp light cut-offs and it will also provide general illumination on wall surfaces. Corridor fixture spacing should not be more than 10' apart.

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8- APPENDIX

Appendix A: Luminaire Distribution Photographs

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Table A1. Product descriptions and classification.

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Table A2. Basic performance characteristics.

All measurements were taken by independent photometric testing laboratories according to LM-

79-08. Only one sample of each product was tested. All measurements are for in-situ

performance, if applicable; refer to Table 1 for luminaire configurations.

1. Product L did not undergo full LM-79 testing via an independent laboratory. Information listed was measured by PNNL. 2. CALiPER testing for the following luminaires showed significantly lower luminaire lumens than expected from the

manufacturer-provided photometric files: type I (86%), type K (84%), type P (78%), and type W (56%). Types I and K are fluorescent benchmarks, and this may reflect a difference between relative photometry and absolute photometry. CALiPER has seen reductions up to 15% in past evaluations for fluorescent luminaires. The differences for LED luminaires P and W were not explained. All other CALiPER test results were within 10% of expected values.

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Appendix B: Polar Plots of Luminous Intensity Distribution

Figure B1: Polar plots of luminous intensity for product types A through I. Plots are not to scale.

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Figure B2: Polar plots of luminous intensity for product types J through R. Plots are not to scale.

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Figure B3: Polar plots of luminous intensity for product types S through X. Plots are not to scale.

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Appendix C: Flicker Waveforms

Figure C1: Dimming and flicker characteristics for product types A through D.

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Figure C2: Dimming and flicker characteristics for product types E through H.

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Figure C3: Dimming and flicker characteristics for product types I through M.

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Figure C4: Dimming and flicker characteristics for product types N through Q.

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Figure C5: Dimming and flicker characteristics for product types R through U.

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Figure C6: Dimming and flicker characteristics for product types V through X.

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