Shared Flashcard Set

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Light Sources
Building Technology V - Chapter 12
68
Architecture
Undergraduate 4
10/30/2012

Additional Architecture Flashcards

 


 

Cards

Term
daylight
Definition
name the most perfect light source
Term
most efficient, most pleasing to eye, most economical
Definition
characteristics of daylight
Term
position of sun in sky, weather (degree of cloudiness), natural and built obstructions
Definition
what does the amount of light depend on?
Term
cloudless, cloudless turbid, intermediate, overcast
Definition
four basic models of luminance distribution
Term
overcast, clear, partly cloudy
Definition
sky conditions
Term
overcast sky
Definition
standard measurement for daylighting when all light is diffuse
Term
non-uniform brightness
Definition
brightness at top of skydone, less so at horizon
Term
the illuminance at the horizontal and vertical planes
Definition
what varies as solar altitude changes?
Term
direct light from sun, diffuse light from sky dome
Definition
what are the two sources in a clear sky?
Term
total illumination for horizontal surfaces
Definition
sum of direct and diffuse light and varies with solar altitude
Term
total illumination for vertical surfaces
Definition
sum of direct and diffuse light and varies with solar altitude and azimuth
Term
partly cloudy sky
Definition
impossible to predict due to the limitless variability of conditions
Term
partly cloudy sky
Definition
what produces more interior daylight than clear skylight?
Term
Low cost, instant start and restart, inexpensive dimming, simple installation, cheap fixtures, good as point source, high power factor, full-spectrum color, great for skin tones
Definition
advantages of incandescent lamps
Term

 

low efficiency (14.8lm/W), short life, voltage sensitivity

Governments around the world have passed measures to prohibit sale

Definition
disadvantages of incandescent lamps
Term
incandescent lamps
Definition
tungsten filament inside glass filled, sealed bulb
Term
incandescent lamps
Definition

light source with many different bulb and base sizes

 

coated inside with white silica for greater diffusion

 

most have screw bases, medium screw base most common

Term
R and PAR
Definition
most common reflector lamps
Term
ER
Definition
most common reflector lamp
Term

use inside

 

use outside

Definition

R for a reflector lamp means?

 

and PAR means?

 

Term
tugsten-halogen lamp
Definition
incandescent lamp filled with halogen gas and inside of a small quartz glass bulb (screw or pin connection)
Term
longer life, lower lumen depreciation, smaller envelope, great as a point source
Definition
advantages of tungsten-halogen lamps
Term
still low efficacy, high temp, can explode (requires sheilding)
Definition
disadvantages of tungsten-halogen lamps
Term
gaseous discharge lamps
Definition
flourescent high-intensity discharge lamps (mercury vapor, sodium and metal-halide)
Term
ballasts
Definition
provide high voltage to heat lamp filaments in pre-heat and rapid start circuits; strike arc through tube; limit lamp operating current
Term
ballast factor
Definition

 

low bf = low operating cost, but produces less light; high bf = more energy use, more light, also means less fixtures, so in new construction this may be least costly

Ballast Efficiency Factor – ratio of bf to power (W) = lm/W

Term
power factor
Definition
more expensive ballast but lower operating costs , smaller conductors, more fixtures per circuit
Term
magnetic, hybrid, electronic
Definition
types of balasts
Term
magnetic
Definition
the obsolete balast type
Term
hybrid
Definition
magnetic transformer + electronic switch
Term
electronic ballast
Definition
ballast types that operate lamps at 20-60kHz = less power loss, high efficacy, lighter, more energy efficient, generate less heat, silent, can be dimmed
Term
high temperatures
Definition
what can lower a ballast life?
Term
12-15 years
Definition
how long do ballasts last?
Term
RFI cause by arc discharge in tube
Definition
what specifies RF noise suppressors and RF noise attenuators for fixtures themselves?
Term
fluorescent lamps
Definition
whats the most predominant lamp type in use?
Term
fluorescent lamps
Definition
sealed cylindrical tube with inert argon and low pressure mercury
Term
cathodes at each end
Definition
what maintains the electric arc in flourescent lamps
Term
the arc
Definition
what produces shore wave UV radation and excites phosphor coating on the inside of the tube emitting diffuse visible radiation?
Term
phosphors
Definition
what controls quantity and spectral quality
Term
preheat flourescent lamps
Definition
type of lamps found in existing buildings?
Term
preheat gas and employ separate starter
Definition
what do older flourescent lamps do as oppose to newer ones?
Term
rapid-start
Definition
now a days what is the most common flourescent lamp starter?
Term

instant-start

 

 

Definition
which flourescent lamp uses a high voltage transformer?
Term
instant-start
Definition
what has half the life of the rapid-start lamp?
Term
instant-start
Definition
what lamp can opperate at really low temperatures?
Term

40W,3350lm, 84lm/W

 

Definition
T12
Term
32W, 2950 lm, 90 lw/W
Definition
T8
Term
28W, 2900lm, 89lm/W
Definition
T5
Term
54W, 5000lm, 85lm/W
Definition
T5HO
Term
compact flourescent lamps
Definition
what can directly replace incandescents?
Term
compact flourescent lamps
Definition
folded fluourescent tubes with a built in ballast
Term
1.5-1.9W fluorescent
Definition
what can a 60W incandescent lamp be replaced with?
Term

life of 10-12,000 hours

 

saves $42 for life of lamp

Definition
What is the life of a compact flourescent lamp and how much money can it save over 6hrs/day?
Term
high intensity discharge lamp
Definition
discharges electricity through high-pressure vapor inside bulb
Term
high intensity discharge lamp
Definition
has poor CRI, except metal-halide
Term
in large areas that need high illuminance, energy efficiency and long life are required
Definition
where would you use a high-intensity discharge lamp?
Term
metal-halide lamps
Definition
what has the best CRI up to 80-90?
Term
metal-halide lamps
Definition

 

Best CRI, up to 80-90

Various bulb types and sizes from 50-1500W

Efficacies of 75-105lm/W; last 10-20,000 hrs

Slow starting – 2-3minutes; restrike 8-10 mins

Hot-restrike ballasts provide instant restart, a must for indoor applications

Term
the color shifts
Definition
why cant you dim a metal-halide lamp?
Term
high pressure with high efficiancy up to 147 lm/W
Definition
characteristic of sodium-vapor lamps
Term
150lm/W
Definition
what efficiency does a low-pressure sodium vapor lamp have?
Term

 

High efficacy, up to 147lm/W

Lowest CRI – 20-22, so don’t use where color rendition matters (yellow color)

High glare so shield or mount up high

Require ballast, slow to light, slower restrike w/out special ballasts

Definition
characteristics of HPS sodium-vapor lamps
Term

 

Highest efficacy, up to 150lm/W

Lowest CRI – 0, so don’t use where color rendition matters (yellow color)

Long life (+18,000 hrs), 100% lumen maintenance

Definition
characteristics of low-pressure sodium vapor lamps
Term
light-emitting diodes
Definition
solid state lamps
Term

 

Light-emitting Diodes (LED):

Definition
has a long life, high energy efficiency, but initial costs are higher than those of flourescent
Term

 

Light-emitting Diodes (LED):

Definition
damaged by high temperatures, so they include heat sinks, cooling fins
Term
the diodes use DC power
Definition
why must led lamps include internal circuits to operate from standard AC voltage?
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