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CHAPTER 15
LIGHTING EQUIPMENT AND SYSTEMS
OVERVIEW
This chapter deals with lighting equipment and systems that are mostly common
sense knowledge since everyone, young or old, has lived in a world that depends on
artificial lighting in all interior spaces, such as homes, work places, and recreational
facilities. On the other hand, we are amazed by the ignorance and lack of knowledge of
the general public on the fundamental differences of light sources.
The Tree of Light (Figure 15-1) is a good illustration about the commonality of all
light sources, but there are day-and-night differences between the characteristics of light
sources: color, luminous efficiency, life, starting characteristics, rate of depreciation, etc.
Those who can master the general characteristics of light sources are potentially good
lighting designers. All leading lamp manufactures, such as General Electric, Philips
Lighting, and Osram-Sylvania, produce comprehensive lamp catalogs that can be
obtained for students. These catalogs contain up-to-date lamp types, performances, and
cost. They are very similar in content. You may want to choose one manufacturer that is
more active in your area. The lamp catalog is a must for your class. In addition, these
manufacturers also print technical bulletins of individual lamp types that provide more
information beyond that included in the general lamp catalog. These are also available
for the asking.
CHAPTER 15
LIGHTING EQUIPMENT AND SYSTEMS
QUESTIONS AND ANSWERS
15.1 Daylight is plentiful and economical; however, it _____ widely and its ____
shifts during the day.
15.2 Fluorescent lamps were first introduced in the ( 1930s ) ( 1940s ) ( 1950s ).
15.3 Light output depreciates with time. The light output of general-service
incandescent lamps is about _____ percent at their rated life.
15.4 The rated life of lamps is based on the time elapsed when only _____ percent
of a group of lamps still remain burning.
15.5 Which light source has a higher color temperature, one that is described as
“warm” or one that is described as “cool”?
15.6 The CRI for a 3000
q
K incandescent lamp is given a rating of 100. Thus, it
can reproduce the true color of any object. ( True ) ( False )
15.7 To reduce the stroboscopic effect from fluorescent and HID lamps, it is
desirable to wire lighting fixtures on alternate circuits or to use lead-lag
ballasts for multiple lamp fixtures. ( True ) ( False )
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15.8 What lamp base is used on a T8 general service fluorescent lamp?
15.9 What does PAR stand for in an incandescent reflector lamp?
15.10 What is the maximum bulb diameter, in inches, of (a) a PAR38 halogen
lamp? (b) a T5 flourescent lamp?
15.11 If the voltage at the lamp socket is 6 percent above the rated voltage of an
incandescent lamp, what is the expected increase in light output? What is
the expected decrease in the life of the lamp?
15.12 All other parameters being equal, is a higher-wattage incandescent lamp
more or less efficient than a lower-wattage lamp?
15.13 The rated life of an HID lamp is determined by operating the lamp at ( )
hours per start.
15.14 Tungsten-halogen lamps contain halogen gas (iodine, fluorine, etc.) that
reacts with the tungsten filament to form a halogen-tungsten compound and
redeposits the tungsten back into the filament, prolonging the life of the
lamp.
( True ) ( False )
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blackening of the bulb. The tungsten-halogen cycle prevents this problem,
prolongs the life and reduces the light depreciation.
15.15 The rated life of a fluorescent lamp is determined by operating the lamp at (
) hours per start.
15.16 The color temperature of fluorescent lamps is fixed at 3500
q
K. (True)
(False)
15.17 The use of krypton gas in an incandescent lamp results in what benefit?
(a) Increase efficacy
(b) Increase lamp life
15.18 An electromagnetic ballast for fluorescent lamps may consume up to _____
percent of the rated lamp power. If a lamp is rated for 40 W, the ballast may
consume _____ W; thus, the total power consumed by the lamp and ballast
is _____ W.
15.19 Which of the following statements applies to PAR lamps that utilize halogen
capsules?
(a) They are direct replacements for incandescent PAR lamps
(b) They have better beam control than incandescent PAR lamps
(c) They are fully dimmable
(d) They run hotter than incandescent PAR lamps
(e) They produce a whiter light than incandescent PAR lamps
(f) They cannot replace standard R-shaped incandescent lamps
15.20 The light output of a standard 40-W fluorescent lamp is about ( ) percent
of its input energy.
15.21 Name the three major types of high intensity discharge lamps.
15.22 What are the characteristics of LPS lamps?
15.23 How can infrared technology improve the efficacy of tungsten halogen
lamps?
15.24 The efficacy of HPS lamps is as high as _____ lumens/watt, excluding the
power loss of the ballast.
15.25 All HID lamps require a ballast. ( True ) ( False )
15.26 All incandescent lamps have the same color temperature. ( True ) ( False )
15.27 The rated lumen output that appears in a manufacturer’s catalog for a
fluorescent lamp assumes the lamp is operated on a ballast having a ballast
factor of _____.
15.28 The ballast factor is always smaller than 1. ( True ) ( False )
15.29 Where are MR16 nd MR11 lamps typically used?
15.30 List five ways in which aluminized MR16 lamps differ from dichroic MR16
lamps.
(1) Better color stability
15.31 What are the primary benefits of titanium-coated MR16 lamps over other
MR16 types?
15.32 High-pressure sodium lamps are monochromic. ( True ) ( False )
15.33 What is the typical efficacy of a 1000 W clear MH lamp? (85) (100) (150)
lpw.
15.34 What is the depreciated lamp lumen of a 400 W clear HPS lamp at 70% of
its rated life? (65%), (70%), (73%)
15.35 Name two electrodeless lamps.
The two popular electrodeless lamps are:
15.36 What is the difference between the IES and CIE lighting system
classifications?
15.37 What are the two most valuable pieces of data on the performance of a
luminaire in the luminaire’s photometric report?
15.38 What is a light pipe and what are its applications?
.
15.39 In addition to type of light source, installation, and maintenance, what are
the important elements in selecting a lighting fixture for interior space?
15.40 Initial lumens of a light source are typically measured after how many hours
of operation?
100 hours
15.41 Lighting accounts for approximately what percent of all electrical energy
consumed in the United States?
15.42 Define luminous efficacy.
15.43 Theoretically, 1 W of electrical power can be converted to approximately
how many lumens? (a) 600, (b) 60, (c) 6
15.44 What is the approximate lamp life of: (a) Incandescent lamp including
halogen and quartz? (b) Fluorescent and HID lamp?
15.45 What is the approximate luminous efficacy of: (a) Incandescent, (b)
Fluorescent, (c) High intensity discharge lamps?
15.46 For incandescent lamps, how is the rated life related to efficacy?
15.47 The use of rare-earth triphosphor in fluorescent lamps offers what two
benefits?
15.48 Explain briefly the light generating process of a fluorescent lamp.
15.49 For most fluorescent lamps, what are the optimal bulb-wall temperature and
the optimal ambient temperature?
15.50 What are the three most common lamp color temperatures for fluorescent
lamps?
15.51 Rank the luminous efficacy of HID lamps (mercury, metal halide, HPS) in
the order of increased efficacy.
15.52 Rank the following from low to high in luminous efficacy and in color
temperature: (a) Mercury Vapor Lamp, (b) Metal Halide Lamp, (c) High
Pressure Sodium Lamp.
15.53 Which type of lamp has a better lumen depreciation factor – Fluorescent or
Metal Halide?
15.54 Which of the following light sources is (are) monochromic – Fluorescent,
Mercury Vapor, Metal Halide, High Pressure Sodium or Low Pressure
Sodium and LEDs?
15.55 Which of the following is (are) not appropriate for describing a low pressure
sodium lamp? (a) High Luminous Efficacy (b) Poor Color Rendition (c)
Used for Interior Lighting.
Used for interior lighting.
15.56 What is meant by triphosphor?
15.57 What are two basic types of fluorescent lamps and where are they typically
used?
15.58 The newer T5 fluorescent lamps are more efficient than T8 fluorescent
lamps. (True) (False)
(True)
15.59 Ambient temperature has a great effect on the light output of a fluorescent
lamp. (True) (False)
15.60 The newer T5 fluorescent lamps are designed to have a peak light output at
higher ambient temperature than other general-lighting fluorescent lamps.
(True) (False)
(True)
15.61 The newer T5 fluorescent lamps offer luminaire manufacturers what two
design opportunities?
15.62 What is the best application for a fluorescent lighting system that utilizes
programmed rapid-start electronic ballasts and why?
15.63 What two characteristics of higher-wattage compact fluorescent lamps make
them an attractive alternative to low-wattage metal halide lamps?
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15.64 What are two benefits of electrodeless fluorescent lamps over conventional
fluorescent lamps that have cathodes?
15.65 Name three benefits of ceramic metal halide lamps over those that use quartz
arc tubes.
15.66 LEDs produce light (a) in a continuous spectrum or (b) with a nearly
monochromatic spectrum
15.67 The rated life of an LED is based on 50% _________.
(a) survival
(b) of initial light output
15.68 For a directional light source such as a PAR lamp or an MR16 lamp, field
lumens is the output of the lamp taken within _____ percent of the center-
beam candlepower, whereas beam lumens is the output of the lamp taken
within _____ percent of the center-beam candlepower.