LC flashcards
Ballast Efficacy Factor equation
(Ballast Factorx100)/Input Watts
Ballast Efficacy Factor definition
BEF is the ratio of ballast output to input power. Used to compare different ballast on a light output to power consumption basis
In order to compare ballast based on ballat efficacy factor what must be true?
Ballasts are operating the same number and type of lamps
What is the ratio b/w a light source and size of reflect
1:5
What is the equation for NPV when PVfactor is given
NPV = annual savings amount X PVfactor - Initial investment
What is VDT
Video Display Terminal
To avoid direct glare, what should the luminaire shielding angle be
> 45 deg
What does iprgc stand for and what do they do?
Intrinsic photosensitive retinal ganglio cell. 1% of ganglion cells in retina, non-visual but are nerve connection to biologic clock
From LEED what does IEQ, SS, and EA stand for?
Indoor enviornmental quality, and sustainable site, energy & atmosphere
What is VLT?
Variable Light Transmittance. Describes how much visible component of sunlight is transmitted
What is the max sensitivity of cones which wavelengths and colors
555 nm, green/yellow
What information does the UL label provide?
Air tight/sealed, damp/wet, max wattage, IC or nonIC.
Air penetration, water penetration, max electrical, IC, lamp type
What are the boundaries for the non-IC fixtures
Insulation must be more than 3” away from the sides of the fixture and more than 1/2” from top
NEC: splices
Splices must be accessible through ceiling or fixture
NEC: Fixture mounting
Must be secured to building structure
NEC: % cicuirt loading
No more than 80% of capacity
NEC: Restrictions on clothes closet lighting
No pendant
Enclosed
Surface of recessed fluorescent lumianires
Surface or recessed LED identified for use within closets
NEC: fixture dist from goods in residential clothes closet
12” for surface mounted or LED fixtures w/ enclosed
6” for all others
How to determine total amps given voltage and wattage
I = W/V
For 90.1, what controls are needed in exterior dusk to dawn lighting
Photocell or astronomic time switch
90.1 What kind of controls are needed in exterior non dusk to dawn lighting
Photocell & time switch
90.1 What are the parking garage requirements?
Perimeter must use daylight reduction to min of 30% when no activity of max 30min. Lighting zone can be no larger than 3600sqft
Luminance ratios for object to background? distant focal cue? Dominating focal point
Object:Background = 3:1
Object:Focal cue = 10:1
Object: dom.focal point = 100:1
IES targer reflectances for ceiling, walls, and floor
80-50-20
List of non-recoverable light loss factor
Ambient temp, voltage, ballast factor, luminaire surface depreciation
List of recoverable light loss factors
LLD
Lamp Burn Out
LDD
RSDD
Define IP testing. How is the frist level dust protection signaled? How are jets signaled? How is submersion signaled
Ingress protection. 1st level dust IP5X, 1st level Jets IPX5, 1st level submersion IP X7
How to estimate spacing for uplight lumens based on spec
4 - 8 x mounting distance to ceiling
Equation for projected area of luminaire
Surface area x Cosine of viewing angle
Equation for energy cost/year/fixture
Watts x hours x kwh rate / 1000
8 components of integrated daylighting system
Daylight and view aperatures Glazing selection Sun control devices Light redirecting devices Furniture and partitions Room and geometry surfaces Plan form & orientation Lighting controls
When is a nearby building considered a side lighting obstruction
If top of adjacent building is 25deg from horizon then it interferes with side lights
What happens during punch list
Confirm drawings vs. whats installed: lamps, ballasts, power supplies, final aiming, control programming
What does U factor measure
Rate of heat loss
Which RP covers office lighting
RP-1
Which RP covers educational lighting
RP-3
Which RP covers library
RP-4
Which RP covers daylighting
RP-5
Which RP covers economics of lighting
RP-31
Which RP covers roadway
RP-8
How do you calculate daylight section depth from sidelighting (primary and secondary)
Zone 1 - Primary - Head height of window
Zone 2 - Secondary - Hed height of window times 2
What is a perfectly diffuse surface called
Lambertian
What kind of reflectance creates a mirror image
Specular
List the steps of the design process in order
Programming Schematic Design Design Development Contact docs Bidding & Negotiation Construction Administration Post occupancy eval
List the facotrs of visibility and task performance
Luminance, Contrast, Color contrast, size, movement, time, age
During which design step do you determine existing building conditions
Programming existing conditions
During which design step do you determine design constraints
Programming design givens
During which design step do you determine design goals
Programming design goals
During which design step do you determine design criteria
Programming design criteria
What is a solar shade and what does it do
A mesh blind along windws which blocks direct sun, allows for a view, reduces heat gain, allows diffuse light to come through
During which design step do you submit and/or review lighting cut sheets
Construction Administration
Define scotopic vision? What fc level, where is peak wavelenght? what anatomy?
Vision when adapted to dark enviorment. <0.1fc or <0.034cd/m2. Rods only, no fovea, no color, peripheral. Peak wavelength = 500nm
Define photopic vision? What fc level, what anatomy? Where is peak wavelength?
Vision adapted to most interior lighted conditions. >1fc or >3.4cd/m2. Cone, foveal, color, detail. 550nm peak
What tool is used to measure luminous intensity and what is the unit of measure
Goniophotometer, candela
List CIE indoor classifications and the % uplight and downligh
Direct - 90-100 Semi-Direct - 60-90 Direct/Indirect - 50 - batwing uplight General Diffuse - 40-60 Semi-indirect - 10-40 Indirect 0-10
During which design step do you select specific luminaires
Design Development
Discuss the acitons and physiology of accommodation
Ability to focus at different distances. Lens is adjusted in convexity and length
Discuss the actions and physiology of adaptation
Changing sensitivity to light levels. Pupil change size, neural system changes, change in rods/cones activation
Which vision has S/P ratios
Mesopic
During which design step do you create a controls schedule
Contact documentation
Luminance, define, symbol, unit of measure
Measure of light emitting from a surface in a specific direction. L - cd/ft^2, cd/m*2
What are the wavelength ranges of the visual spectrum
380-780, ROYGBIV high to low Red, orange, yellow, green, blue, indigo, violet.
What does PAR stand for
Parabolic aluminized reflector or pressed reflector lamp.
Define visual acuity
Ability to distinguish a visual task
Which lighting measurement do we perceive
Luminance
Discuss quantity and dispersion of rods and cones on the retina
Rods: 120 million - Dispersed evenly over retina except none in fovea
Cones: 8 million. Heavily concentrated in fovea, sparse elsewhere
Describe halogen cycle
Tungsten atoms evaporate from filament, combine with halogen atoms, tung-hal return to filament, redepost tungsten, halogen is released to do it again
Max sensitivity of roads and what wavelength/color
507 nm, blue/green
What happens before and during design development
Before: Programming, schematic design
During: details of lighting, select luminaires, layout, controls
What happens before and during bidding
Before: Programming Schematic Design Detailed Design Contract Documents During: Financial analysis, negotiation
Programming, which step and what are actions
Step 1 - Survey, audit
Owner & design team preferences &impressions
Visual & perceptual needs
Security issues
Architectural opportunities and constraints
Photometric considerations of existing installation
Budget
Energy Limitations
Maintenance concerns
What is best direction for side lighting
North with south as second. North doesn’t recieve much direct sun, while south can be controlled easily. East and West causes direct sun which is hard to mitigate
During which design step do you determine the desired lighting results
programming
Equation for life cycle cost
Cost to buy + cost to maintain + life energy cost + replacement cost - salvage value
For Haz what does class 1, 2, and 3 mean? What does div 1 or div 2
Class 1: Flammable Gas Class 2: Combustible dust Class 3: Combustible fiber Div1: Normal Operations Div2: Abnormal operations
What comes before schematic design? What is done during it
Programming. Design considerations Originate scheme or concept for lighting (mockup) & present Review RP's Prelim budge
Definte Daylight setback or holdback
When occ sensor has photocell override and won’t turn light on if people are in the space AND illuminance meets daylight set point.
Exitance, define symbol unit of measure
Total light coming off a surface. M. lm/ft^2
During which design step do you determine the desired lighting effects
Schematic design
Define Mesopic. What FC level, what anatomy
Vision at low ambient. 0.1`
Name three forms of daylighting
Sky light, reflected light (off bldg, road, grnd), direct sunlight
List NFPA 101 emergency egress reqs
Initial avg >= 1fc. Initial min >=0.1ftc. Max:min <= 40:1
Lights to stay on for 90 min
% of lumens to maintain at the end of 90 min: 60%
Test EM lighting for 30 sec every 30 days and 1.5 hours once a year
No more than a 10 sec delay when switching
Define Spatial daylight autonomy (SDA)
% of annual daytime hours that a given point in a space is above a specificed illumination level due to daylighting only. Ex. SDA300,50% means 300lux for 50% of the operating hours in a year.
Define continuous daylight autonomy
Same as daylight autonomy but additional credits if light is below the user defined threshold
Illuminance: define, symbol, UOM
Density of light on a surface: E, fx or lux
Define Luminaire efficiency
Ratio of luminous flux emitted by a luminaire to the luminous flux emitted by the lamp(s)
Lamp Efficacy
LPW
How do you determine max allowable spacing using SC
Max spacing = SC X H
Define coefficient of utilization
% of lumens from lamp that make their way to the work plane
What happens in the post occupancy evaluation?
Operations and maintenance, audit lighting performance, energy consumption, user experience
What comes before construction administation and what happens during
Bidding comes before.
Review submittals, change orders, installation, punch list, commissioning
Name three things that factor into the point method of calculation
Intensity, distance, angle -
Ehor = Horziontal illuminance (fc, lux) = I (luminious intensity, cd) * cos(angle)/ D^2
Evert same as horzi but sin(angle)
What can you do to make a space seem more intimate
Light the horizontal surfaces
What can you do to make a space seem larger
Light the vertical surfaces
What can you do to bring out texture of a wall/surface
Graze
Contract/construction documents what comes before
Design Development comes before. Controls schedule/spec Detailed drawings Lighting schedule/spec Lighting and controls plan
Lamp seasoning time and on time before measurements post seasoning
No more than 20 hours for incandescent
100 hours for gases (fluorescent, HID, LPS).
if seasoning is not necessary allow HID and Fluorescent 1 hour to warm up.
List NFPA 101 egress requirements
Min 1fc avg no less than 0.1 fc along path. 40:1 max, New stairs:10fc, Old Stairs 1fc. Assembly occupancies on exit access 0.2fc. No single lamp failure can result in <0.2fc.
Occ sensors with min 15 min delay
ADA spacing regarding lightings is what
Wall sconces can not protrude more then 4” b/w 27” and 80” AFF
Define beam angle and field angle
Beam angle = 50% of max intensity in both directions
Field: 10% of max intensity both directions
Zonal cavity calc give what
Horizontal illuminance
Mix and get what:
Blue and Green
Green and red
Red and blue
Cyan
Yellow
Magenta
If investing do you want NPV to be more or less money when comparing options
Less. Less it costs in today’s money the better
How does discount rate effect project finances
Lower the discount rate, the less effect time has on value
Equation for simple payback and ROI
Simple Payback = Investment/annual savings (years)
ROI = savings/investment (percentage)
The longer the simple payment the _____ percentage the ROI will be
Lower
Horizontal blinds are best for which windows?
Vertical blinds are best for?
Horizontal: South facing
Vertical: East or west facing
Discuss items affecting voltage drop and how to remedy
Gauge of wire, load, voltage, distance Increase gauge (smaller number) Increase voltage Shorten run Reduce load
If area is daylight what should the CCT be
3500K or greater
What does LSG stand for and mean?
Solar Heat gain Ratio. Need to look up
What does SHGC stand for and mean?
Solar heat gain coefficient. Need to look up.
Define Ampere
Intensity of electrical flow. Symbol is “I” or “A”
Adaptation
Process by which retina becomes accustomed to more or less light than immediately preceding period.
Average rated life
Hours when 50% of a large group of lamps have failed when operated on a nominal lamp voltage and current. 3 hours/start for fluorescent, 10 hours/start for HID
Ballast efficacy factor (BEF)
Ballast factor (x 100 to produce a whole number) divided by input watts. Used to measure the level of efficiency of similar ballast models.
Ballast factor
Measurability of a particular ballast to produce light from the lamps it powers. Derived by the lumen output of a particular lamp/ballast combination divided by the lumen output of the same lamps on a reference ballast.
Ballast types
Magnetic, Hybrid or “low frequency”, High frequency electronic
Magnetic ballast
Inefficient device used a core and coil assembly transformer to perform the minimum functions to start and operate a lamp
Hybrid/Low frequency Electronic
A magnetic ballast with a few electronic components that switch off voltage to the lamp coil once lamp has started. Minimal increase in efficiency is obtained with more expensive magnetic core material and turning off power to coils during operation
High frequency electronic
Operates lamps above 20,000 hz. Best efficiency for traditional technologies
Passive daylighting system
Daylighting system using photocells, shades and lighting control
Active daylighting system
Uses heliostat to track and direct sunlight
Candela
Measurement of luminous intensity
Candlepower distribution
Represents variation in luminous intensity in cd in a plane through the light center of the lamp. Typical distribution graph
Center beam Candle Power (CBCP)
Intensity of light produced at center (nadir) of a reflector lamp beam
Coefficient of utilization
% of lamp lumens that are received on the work plan. Function of luminaire efficiency, room geometry, and room surface reflectances. CU values found on the spec sheet.
Cut off angle
Angle measured from nadir to the first line of sight at which the bare source is not visible
CIE: Direct luminaire
90-100% light down
Disability glare
Reduces ability to perceive visual information. Too much light becomes scattered in the eye
Luminaire efficiency
Ratio of lumen output of the fixture divided by lumen output of the lamps alone
How do fluorescent lamps work?
Low pressure mercury discharge lamp with fluorescing coating (phosphor) transforms UV to visible light.
Footcandle
Measurement of illuminances. (1lm/ft2)
Lux
Measurement of illuminances. (1lm/m2)
Harmonic
Electronic frequency that is an integer multiple of the fundamental frequency ex. 60 hz is fundamental, 120 hz is 2nd harmonic, 180 is 3rd harmonic. THD reflects the distortion to these.
How does an HID lamp work?
Electronic discharge lamp where a light producing arc is stabilized by a wall temperature and the arc tube. Need more info here!
How does an HPS lamp work?
HID lamp where light is produced by passing electric current through sodium vapor. Can operate in any position and be clear or coated
Illuminance
Light falling (incident) on a surface. Not perceived to the eye but rather reflected light is (luminance)
Induction lamp
Light generated by induction or transmission of energy via magnetic field + gas discharge. No electrodes. Very long rated life 60,000-100,000 hours
Incident light
Light that falls onto a surface or object
CIE indirect lighting
0-10% down
Instant Start Ballast
Apply high voltage across lamp with no preheating of the cathode. Most energy efficient starting method for fluorescent lamp ballasting. 1.5 - 2 W less than rapid start. Less complex wiring, works at colder temps. Shorter lamp life if frequent switching
Lamp Current crest factor (LCCF)
Ratio of peak lamp current to the RMS (average) lamp current. Lamp manufacturers require an LCCF of <1.7 for long lamp life
How to calculate LLD
Mean lumens/Initial Lumens
Luminance
Referred to as brightness of photometric brightness. Portion of lighting the eye perceives. Light reflected off or transmitted through a surface in a given direction
Maintained Illuminance Level
Initial illumination level from luminaires adjusted for LLF’s
Mean lumens
For fluorescent and HID typically measured at 40% life. HPS and Mercury measured at 50% life. Not typically measured for filament lamps
Mercury Vapor Lamps
Produces light by passing an electric current through mercury vapor. Electrodes made of tungsten. Emission material slowly evaporates from electrode
MH lamp
HID lamp in which visible light is produce by radition of metal halides. Bulbs can be clear or phosphor coated
Power factor
Measure of the effectiveness with which an electrical devices converts volt-amperes to watts
Programmed Rapid start
Method of starting fluorescent lamps where cathode heat is applied prior to the lamp being ignited. Preferred mode of lamp stating for applications with occ sensors or several on/off cycles per day. Same temperature as instant start
Rapid start
Preheat cathodes. Slight starting delay. 50F
TCLP (Toxicity characteristic leaching procedure)
EPA regulated test to determine whether waste is to be treated as hazardous or non-hazardous
Trigger start
Circuit used to eliminate the start and start the preheat lamp almost instantly
Tungsten Halogen Lamp
Gas filled tungsten incandescent lamp containing certain proportion of halogens
RFI
Radio frequency interference
IS
Instant Start ballast
PS
Programmed Start
RS
Rapid Start
TCLP
Toxicity Characteristic leaching procedure
EPACT
Energy Policy Act of 1992, min LPW, lamp labeling for incandescent and fluorescent. Requires all states to adopt a building code that meets or exceeds 90.1
FEMP
Federal Energy Management Program provides guidance on lamp purchases
RCRA
Resource Conservation and Recovery Act 1990 - created the TCLP
RSDR
Room Surface Dirt depreciation
LBO
Lamp burnout factor - Ratio of illuminance (or exitance or luminance) provided when a lighting system is allowed to operate with a set number of lamps burned out to that provided when all lamps are operating
First level analysis
Cost of light, simple payback, simple rate of return
Second level analysis
LCCBA, Savings-investment ratio, internal rate of return
BCD
Borderline between comfort and discomfort. Average luminance of a source produces a sensation b/w comfort and discomfort
BRDF
Bidirectional reflectance distribution function - describe how light is reflected (output, color, angle) at an opaque surface.
MF
Maintenance Factor
RTP
Relative Task performance
RVP
Relative visual performance
VCP
Visual Comfort probability - Rating of a lighting system expressed as a % of people (in identical situations) who find the lighting acceptable in terms of discomfort glare. Higher is better
Iris
Regulates the amount of light that enters the eye. Forms the colored visible part of the sys in front of the lens. Light entes through a central opening (pupil)
Cornea
Transparent circular part of the front of the eyeball. Refracts light entering the eye onto the lens. Very sensitive to pain
Lens
Behind the Iris/pupil. Helps refract incoming light and focus it onto the retina. Cataract is when lens becomes cloudy
Choroid
Middle layer of eye between retina and sclera. Contains pigment that absorbs excess light to prevent blurred vision
Ciliary Body
Part of the eye that connects the choroid to the iris
Retina
Light sensitive layer that lines the interior of the eye. Contains rods and cones.
Macula
Small central portion of the retina provides the clearest most distinct vision. When looking directly at something the light from that object forms an image on one macula
Fovea
Center of macula. Cones only. To detect faint stars in the sky don’t look directly at them then the rods will pick it up
Optic disk
Portion of the optic nerve found on the retina. Blind spot
Optic nerve
Leaves the eye at the optic disk, transfers all visual information to the brain
Sclera
White part of eye.
Owner & Design team preferences & impressions
Programming
Space function
Building materials, room finishes, architectural style
Space plan, furniture style
Important features (ex. art & signage)
Comfort level and satisfaction of occupants
Need for flexibility of space function
Exterior features: image, security, landscape
Visual and Perceptual needs
Programming
Age
Tasks to be performed, importance and duration
Times of occupancy
Psychological needs for light
Shape of task particularly in industrial areas
Architectural opportunities and constraints
Programming
Architectural features, interior and exterior
Historical constraints
Ceiling heights, type
Plenum depth
Location and size of structural members and mechanical ducts
Window and skylight locations & orientations
Construction safety codes
Electrical system
Construction schedule
Landscape features
Photometric considerations
Programming
Critical vision: task areas & immediate surround
General field of view: highlights and ambient
Distinct surround: circulation, transitional areas
Budget
Programming
Initial cost (installed)
Maintenance and energy cost
Life-cycle cost
Energy limitations
Programming
Energy code requirements
Incentive programs
Maintenance considerations
Programming Lamp Performance Type of environment LDD RSDD Planned maintenance program
Lighting effects
Enlarging space Smaller or more intimate Grazing Wall washing Framing Accent Ambient Visible fixtures
How do you use light to enlarge a space
Indirect and ambient light. Bright and evenly lit ceiling, wall, and floor, high reflectance surfaces
How do you use light to make a space look smaller/more intimate
Direct shielded luminaires recessed, concentrated beam spreads
Typical lamp efficacies
Incandescent - 10-40LPW Halogen - 20-45 Fluorescent - 35-105 Mercury - 50-60 MH - 60-120 HPS- 60-140
Typical lamp lumens
100W A19 - 1500lm 100W Halogen T4 - 1800lm 32W CFL 4 pin - 2400lm F32T8 - 2950lm Fluorescent FP28T5 - 2600-2900lm Pulse start 100W MH - 8500lm 100W HPS clear E17 - 9500lm
What does NEC codify
Sizing of wires and conduit Mounting methods of fixtures and conduit Sizing of breakers/dimmers/fuses Wiring methods Types of lighting for single residence, multi-residence, and commercial buildings
Building Area method
Used in 90.1 - quick and simple process for calculating prescriptive interior lighting power allowance for whole building types.
LPA = Lighting power (watts) / Area
Space by space method
Used in 90.1 - LPA calculated room by room
LPA = Lighting power (watts)/Area
NEMA classification
Used on Floodlights only - Based on field angle
Higher field angle larger NEMA number
1-7
Results in horizontal and vertical ex. NEMA 5 X4
ADAAG
Americans with Disability Act Accessibility guidance:
Size and height of wall sconces
Requirements for illuminated exit signs to provide sound and flashing light
LEED optimization energy performance requirements required what percent below 90.1
Meet for qualification, additional points for each 10%
Daylight penetration based on head height
1.5 - 2 X head height
What % loading can you load a circuit?
80% for safety
What lighting technology flickers at the end of it’s life
HPS
IES Roadway and Area Luminaire Classifications: Type 1
oblong with small bumps forward and backward at center. Good for walkways, paths, and sidewalks. Narrower paths or roadway. Located on median
IES Roadway and Area Luminaire Classifications: Type 2
oblong wider the one no bumps. Wide walkways, ramps, entrance roadways. Located near roadside.
IES Roadway and Area Luminaire Classifications: Type 3
oblong wider than 2. General roadway lighting, parking areas. Larger area of light required.
IES Roadway and Area Luminaire Classifications: Type 4
oblong wider than 3 (forward throw). Semi circular. Perimeter of parking areas and businesses.
IES Roadway and Area Luminaire Classifications: Type 5
Circular
IES Roadway and Area Luminaire Classifications: Type 6
Square with defined edge
Atrium daylight technique
Large skylight at center of multi story building. Each level can get some sunlight.
Clerestory
Vertical windows above eye level. Commonly additional roof pieces similar to a single saw on a sawtooth design
What is 1 m in ft
3.28
Initial Cost
Luminaire + Lamps + installation + labor + shipping
Utility cost
hours x kw x $/kwh
Maintenance cost
cost of lamps + cost of labor + business income loss during maintenance
Apparent power
Measured in volt ampere. Beer and foam analogy
Visual Acuity
Ability of the eye to discern detail.
Factors: size, luminance, constrast, time, and color
For emergency lighting are photoluminescent paints and products sufficient for egress
No, they can be a supplement
Max dist between exit signs
100ft
Externally and internally lit exit signs
Externally lit exit signs must have constrast of 0.5 and 5fc. Internally lit signed must be tested to UL 924
Halogen cycle
Tungsten atoms evaporate from filament.
Tungsten atoms combine with halogen atoms
Compound returns to filament redepositing tungsten
Halogen atoms released to recombine with other tungsten atoms
Lamberts cosine law
Reflected or transmitted luminous intensity in any direction from an element of a perfectly diffusing surface will result in luminance being the same regardless of viewing angle.
Lambertian surface is perfectly matte
NFPA 70 NEC EM
Uninterrupted power source when switching to EM power.
HID sources must provide continuous light when switched from normal to EM if part of EM system
NFPA 101
Illumination levels.
Test procedure
AFF
Above finished floor
How do convex and concave lenses affect light
Convex lens focus rays to a focal point. Distance to focal point is focal length.
Concave lens spread light
Factors to determine illuminance levels
Task Characteristics
Task importance
Observer characteristics
What are submittals? Who writes them? When do you get submitted? Who reviews them?
All documentation created by the contractor detailing specific products, data, instructions, and other information regarding the build. Submitted in the Construction administration. Design team reviews
What are shop drawings? Who writes them? When do you get them? Who reviews
Fabrication and installation drawings specific to the project. Contractor writes them and provides to the design team during the construction administration.
When should group lamping be done
80% of rated life
T12, T8, T5 which use the same socket? Can they use the same ballast?
T12 and T8. No require a ballast change
Type A, Type B, Type C, and Dual what do they mean
Type A - Plug and play, Type B - Line voltage, Type C - New Driver, Dual mode - Plug and play or line voltage
What is LCL?
Light center length
Define Probe start
No ignitor, electrical contacts to ignite gas and remain lit - Old tech
Define Pulse Start
2 contacts and ignitor, rapid restrike, quick start up - newer
How does a PIR sensor work?
Detects heat from a body, direct line of sight needed
How does ultrasonic work?
Shoots out ultrasonic waves and sees any distrortion that comes back. Do not need a line of sight
Plug load controls
Any sensor that controls a power strip or outlet
Typical spacing for illuminance measurements
2ft grid
Overhead glare - what angles how many cd
above 55-60 deg, 12,000 cd/m2
What percentage of daylit hours are needed to be considered effective daylight design
2/3
For 90.1, automatic shut off is not required for what scenarios
- Shop and Lab classrooms - safety
- Spaces where an automatic shutoff would endanger the safety or security of the room or building occupants.
- Lighitng required for 24/7 operation
What are the lengths of T8 and T5
T8 - 47.8”
T5 - 45.8
At what rated life % should you group relamp
60% - 90% rated life
What percentage of lighting alterations is the trigger to comply with 90.1
20% as long as the lighting power is not increased which is also a trigger
What does exceeding the RCR threshold for LEED help with?
Gives additional LPD increase = LPD base *0.2
For Phase cut dimming, what are forward phase and reverse phase also called?
Forward Phase - Leading edge also known as triac
Reverse phase - Trailing edge also ELC - electronic low voltage
What is the max luminance ratio for task to immediate background surface
3:1
What is the max luminance ratio for task to dimmer distant background
10:1
What is the max luminance ratio for task to brighter distant background
1:10
What is the max luminance for task to daylights or luminaires
1:40
What is the max luminance for negative polarity monitor in critical and normal sitations compared to bright ceiling/walls
4: 1 for critical
8: 1 for normal
When looking at a linear fixture the plane that cuts through the short width is what? The plane that cuts through the longways is what?
Short width is - perpendicular, across, normal
Longways is - parallel, along
Operating cost includes
Electricity, replacement lamps, cleaning, disposal
What is the ADAAG requirement for illumination of elevators
5fc
Within sustainable sites for LEED, light pollution allows what type of uplighting
Uplighting that is fully contained in the canopy
What type of uplight contributes to skyglow?
Uplight low because it interacts with more air
What is the min ceiling height when using indirect?
Must be at least 9’ high ceiling
When mounting indirect fixture what height should they be aware form the ceiling?
18” Minimum
What is more important for daylighting? Latitude or longitude?
Latitude.
What type of lamp is a general service lamp
A type
What lamp technology is an MR16
Halogen
What are the primary colors
Red, green, and blue
What is the visible spectrum
380nm - 770nm
What nm are these colors:
Blue
Green
Red
400-500
500-600
600-700
