CHAPTER 17
LIGHTING EQUIPMENT AND SYSTEMS
OVERVIEW
This chapter describes 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, 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 provides
more information beyond that included in the general lamp catalog. These are also available for
the asking.
There are thousands of lighting fixtures (luminaires) produced in this country and
worldwide. Those fixtures need to be illustrated in full color beyond the space that can be
included in the book. We suggest you obtain some of the loose-leaf pamphlets of well-designed
and illustrated types for the class to practice on the selection of luminaires. The pamphlets should
include the performance data of the luminaire including photometric charts on polar coordinates,
and coefficient of utilization table as minimum.
New lamp types are being developed periodical which may not be available at the time
we are preparing this manuscript. Any exciting new products would be good to include in your
class as handouts.
Table 17.2 General Characteristics of Commonly Used Light Sources contains valuable
information compressed in one place. Even though the values of these light source characteristics
may change slightly as new products are being introduced, the relative value should remain valid
for many years after the publication of this edition.
CHAPTER 17
LIGHTING EQUIPMENT AND SYSTEMS
QUESTIONS AND ANSWERS
17.1 Lighting accounts for approximately what percentage of all electrical energy
consumed in the United States?
17.2 Define luminous efficacy.
17.3 Theoretically 1 W of electric power can be converted to how many lumens: (a) 600,
(b) 60, or (c) 6?
17.4 Daylight is plentiful and economical; however, it _____ widely and its ____ shifts
during the day.
17.4 Fluorescent lamps were first introduced in the ( 1930s ) ( 1940s ) ( 1950s ).
17.5 The rated life of lamps is based on the time elapsed when only _____ percent of a
group of lamps still remain burning.
17.6 The rated life of most LED sources is based on the time elapsed when the light output
is only ( ) percent initial lumens.
17.7 Which light source has a higher color temperature, one that is describe as “warm”
or one that is described as “cool”?
17.8 The CRI for a 3000K incandescent lamp is given a rating of 100. Thus, it can
reproduce the true color of any object. ( True ) ( False )
17.9 What does PAR stand for in an incandescent reflector lamp?
17.10 What is the maximum bulb diameter, in inches, of (a) a PAR38 halogen
lamp? (b) a T5 flourescent lamp?
(a) 4-3/4”; (b) 5/8”
17.11 The rated life of a fluorescent lamps is determined by operating the lamp at ( )
hours per start.
17.12 The color temperature of fluorescent lamps is fixed at 3500K. (True) (False)
17.13 Rank the luminous efficacy of HID lamps (mercury, metal halide, HPS) in the order
of increased efficacy.
17.14 Rank the color temperature of HID lamps (mercury, metal halide, HPS) in the order
of increased deg. K (decreased warmth).
17.15 What are the characteristics of metal halide lamps?
17.16 The efficacy of HPS lamps is as high as _____ lumens/watt, excluding the power
loss of the ballast.
17.17 All incandescent lamps have the same color temperature. (True/False)
17.18 Magnetic ballasts are obsolete and no longer used for fluorescent and HID fixtures
(True/False). Explain.
17.19 Where are MR16 nd MR11 lamps typically used?
17.20 High-pressure sodium lamps would be appropriate for a parking lot due to energy
efficiency (True/False). Explain.
17.21 What qualities of ceramic-arc-tube metal halide lamps would make them appropriate
for a “big box” store?
17.22 What are the two most valuable pieces of data on the performance of a luminaire in
the luminaire’s photometric report?
17.23 In addition to type of light source, installation and maintenance, what are the
important elements in selecting a lighting fixture for interior space?
17.24 What is the approximate lamp life of
(a) An incandescent lamp including halogen and quartz?
(b) A fluorescent and HID lamp?
(c) An LED?
17.25 What is the approximate luminous efficacy range of: (a) Incandescent, (b)
Fluorescent, (c) High intensity discharge lamps d. LED?
17.26 Explain briefly the light generating process of a fluorescent lamp.
17.27 Explain briefly the light-generating process of HID lamps.
High-intensity discharge lamps incorporate a high-pressure arc tube within the lamp
17.28 Explain briefly the light-generating process of LED sources.
17.29 For most fluorescent lamps, what are the optimal bulb-wall temperature and the
optimal ambient temperature?
17.30 How does low ambient temperature and high ambient temperature affect LED
performance?
17.31 T5 fluorescent lamps are more efficient than T8 fluorescent lamps. (True) (False)
17.32 The newer T5 fluorescent lamps offer luminaire manufacturers what two design
opportunities?
17.33 What two characteristics of higher-wattage compact fluorescent lamps make them
an attractive alternative to low-wattage metal halide lamps?
17.34 What is the primary benefit of LED lighting?
17.35 Virtually every popular light source can be replaced by a superior LED. (True/False)
17.36 What characteristics are important in the construction of outdoor fixtures?
17.37 When would an outdoor fixture with asymmetrical distribution be appropriate?
17.38 How can outdoor lighting be designed to avoid light pollution?