Guide to Types of Light Bulbs & Lamps
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A guide to light bulbs ("lamps"): Here we provide a guide to the different types of light bulbs (lamps) used in indoor light fixtures. We describe the indoor use of halogen lights, and low-voltage lights. We provide a guide for using fluorescent lights and compact fluorescent bulbs indoors and we include a table comparing fluorescent bulb light levels to incandescent light bulbs. And we discuss issues surrounding the color temperature of fluorescent lighting. This article series details guidelines for selecting and installing interior lighting to meet the requirements for different building areas.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Guide to Lamp Types & Types of Bulbs for Indoor Lighting
Here we provide a guide to the different types of light bulbs (lamps) used in indoor light fixtures. This article series details guidelines for selecting and installing interior lighting to meet the requirements for different building areas. This article includes excerpts or adaptations from Best Practices Guide to Residential Construction, by Steven Bliss, courtesy of Wiley & Sons. Our page top photo illustrates dramatic use of lighting at the Metropolitan Opera building in New York City.
More detail about lamp or bulb types including abbreviations and feature comparisons can be read at Lamp & Bulb Abbreviations & Types. Also see LIGHTING, INTERIOR GUIDE our home page for information about all lighting topics relating to building interior There is a vast array of choices in light bulbs, known in
the lighting industry as “lamps.”
For residential lighting, the
main choices are incandescent, halogen, low-voltage,
tubular fluorescent, and compact fluorescent.
Which lamp
to choose for a given application will depend upon the
amount of light needed (lumens), color of light desired,
type of fixture (luminaire), and whether the application
calls for a directed beam or a diffused light source.
Table Comparing Fluorescent bulb Light Output to Standard Incandescent Light Bulb Output
Also, some lamps are more energy-efficient, providing more lumens for the same amount of electricity consumed.
Fluorescent's are the most efficient, using up to 70% less energy than an equivalent incandescent bulb (see Table 5-22). |
Incandescent Light Bulbs
Incandescent light bulbs include the familiar non directional “A”
lamps, as well as a variety of directional flood and spot
lamps designated by an “R” or “BR.”
Incandescent's have a
low color temperature of around 2700 K, which produces a
warm light with lots of red and yellow tones that make skin,
natural wood, and other warm colors look good.
To some
extent, things look good to us under incandescent light because
it is what we are most accustomed to.
Incandescent
lamps are inexpensive and are easy to dim, but they are also
the least efficient type of bulb and the shortest lived.
Our photo (above-left) illustrates an antique ceiling light fixture using incandescent bulbs in a home in Wappingers Falls, NY. Originally the fixture included small glass shades around each bulb - yet to be restored by the editor - DF.
A second, simple incandescent bulb is shown at left, in an outdoor light fixture where we found its bulb base loose and ready to short out.
And this bulb, a 75-watt unit was over-watted for the fixture whose sticker warned that 60-watts was its limit. Installing a bulb of higher watt-rating than the fixture permits is a fire hazard.
Halogen Lights for Use Indoors
Halogen bulbs, also known as tungsten-halogen, is actually a
kind of incandescent with more blue and less red light
(3000 K), giving it a whiter appearance than standard incandescent
lamps.
Halogen lamps provide good color rendition
and good light for reading and fine detail work.
When dimmed, however, halogen light becomes more
yellow, like standard incandescent lighting. Also, dimming
can cause a halogen lamp to darken due to tungsten evaporation.
Turning the lamp to full illumination for about
10 minutes will restore its full power.
Halogen lamps tend to be smaller, produce 10 to 15%
more lumens per watt than standard incandescent's., and last
about twice as long. They come in a wide range of beam
spreads and wattages. However, since halogen lights burn
very hot, they must be shielded from contact with other materials
or they can create a fire hazard.
The halogen bulb shown at left is used in work lights and security lights. Work lights using this bulb and in use indoors must be kept a safe distance from combustibles.
Also, the bulbs should
not be touched without wearing a glove (since the oil from
your skin can create a weak spot on the bulb), and should be
cleaned with alcohol.
Halogen PAR (parabolic aluminized
reflector) lamps are enclosed in a protective glass casing,
which allows them to be handled like ordinary bulbs. (See the 12-V bulbs illustrated below).
Low-Voltage lamps are tungsten-halogen, incandescent,
or the newer xenon lamps, operating at 12 volts DC. Their
small size makes them ideal for under cabinet lighting, and
their very precise beam control makes them well-suited to
accent lighting of artwork. Many low-voltage fixtures allow
the lamps to rotate within the housing to precisely aim the
beam.
Low-voltage Lighting Guide for Building Interiors
Low voltage lights use a step-down transformer to
convert 120V line voltage to 12 volts DC.
Most newer fixtures
use solid-state electronics, which are more energy efficient
and longer lasting than the older magnetic type.
Transformers are either attached to the fixtures or installed
remotely.
Since the transformers, as well as the lamps and
dimmers, emit a slight hum, remote location can be an advantage.
However, locating the transformer too far from
the fixtures can result in a loss of power and dimming of
the lamps.
When using dimmers with low-voltage lighting,
make sure they are specifically designed for low voltage
systems and for the specific type of transformer.
Fluorescent Lighting Guide for Indoors
Fluorescent bulbs or lamps produce light by energizing the
phosphor coating on the inside of a glass envelope. A device
called the ballast regulates the power needed to start
the lamp and keep it going. Older magnetic ballasts caused
humming and flickering, but new electronic or solid-state
ballasts have eliminated these problems.
Fluorescent's produce three to five times the output as
incandescent lamps [per watt of energy used], last about ten times as long, and stay
very cool.
Because they reduce lighting bills by as much
as 75%, and reduce cooling loads as well, they are heavily
promoted by model energy codes and mandated in some
areas. For example, the California Energy Code requires
that the main lighting in kitchens and baths be fluorescent.
The downside of fluorescent's has always been their
poor color rendering. Standard fluorescent's emphasize the
blue range of the spectrum, giving skin an unflattering,
pale appearance. Manufacturers have worked hard over the
years to improve the light quality.
So-called “deluxe” fluorescent's
offer CRI (color rendering index) values in the
85 to 90 range but with a 25% loss of efficiency. To achieve
CRIs in the high 90s without sacrificing energy efficiency,
manufacturers use more expensive rare earth phosphors,
creating triphosphor and quad-phosphor lamps.
Fluorescent lamps with high CRIs, and color temperatures
within the range of 2700 to 3500K, create pleasing
light for skin tones and natural wood and can blend in with
incandescent lighting. In applications where color accuracy
is important, such as laundry areas, lighting artwork,
and certain hobbies, full-spectrum daylight lamps may be
preferred.
These lamps, which produce light similar to natural
daylight, include General Electric’s Chroma 50 and
Chroma 75.
Dimming also used to be a challenge with fluorescent's
However, using solid-state dimming ballasts and special
dimmers designed for fluorescent's can eliminate any humming
sounds. These also allow a single dimmer switch to
dim groups of fixtures with different length tubes.
Cold Cathode Bulbs
The super-compact fluorescent 120-V bulb shown at left using an Edison base and with a color temperature of around 2700 K is available from TCP, a company offering a wide range of lighting components, bulbs, ballasts. Shown is TCP's "Cold Cathode" 8-watt bulb, item 8G2508CL.[3] This bulb type emits very little heat and is described by the company as especially suitable for signs, marquees, and accent lighting both indoors and outside. The bulbs are also described as excellent for dimming & flashing applications. Photograph courtesy of our associate Charles Soberman.[4]
Note: these Cold Cathode bulbs are UL approved for wet locations in Base Up Position ONLY. |
Guide to Using Compact Fluorescent Lights
Compact fluorescent lights have created a lot more flexibility,
allowing fluorescent's to be used in recessed downlights,
wall sconces, pendants, and just about any type of
luminaire. Early compact fluorescent's were noisy, slow to
start, and had a limited selection of color temperatures.
Newer products, however, are quiet and typically have
rapid-start ballasts. Dimmable ballasts are also available
for compact fluorescent's, but are costly. As with tube fluorescent's,
look for high CRIs and lower (warmer) color
temperatures from 2700 to 3500K to blend in with incandescent
and halogen lighting. All compact fluorescent's
have a minimum 80 CRI.
While some compact fluorescent's have been introduced
that mimic R and PAR-type reflector bulbs, directional
lighting is best achieved with incandescent or halogen
lamps. Fluorescent's are better used for ambient
lighting, indirect lighting, and lighting of closets and storage
areas. Although they cost $5 to $20 per bulb, depending
on the wattage and configuration, they generally pay
for themselves within two to three years in both energy
savings and longevity of the bulbs.
-- Adapted with permission from Best Practices Guide to Residential Construction.
Guide to LED Light Bulbs
Please see LED BULB & LIGHTING TYPES for details about LED light bulbs used in building lighting & light fixtures.
LED bulb brigtness in lumens and energy costs are at our Table of Current LED Bulb Prices & Features.
Industry & Trade Associations for Lighting and Other Interior Components in buildings
American Lighting Association
www.americanlightingassoc.com
-- Adapted with permission from Best Practices Guide to Residential Construction.
Frequently Asked Questions (FAQs)
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Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.
- Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.
- Steve Bliss's Building Advisor at buildingadvisor.com helps homeowners & contractors plan & complete successful building & remodeling projects: buying land, site work, building design, cost estimating, materials & components, & project management through complete construction. Email: info@buildingadvisor.com
Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education.
Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com
- [3] TCP, 325 Campus Drive, Aurora OH 44202, USA, Tel: 800-324-1496, website: www.tcpi.com
- [4] Charles, Soberman, San Miguel de Allende, Guanajuato, Mexico
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
 The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.
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- Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.
- Recommended books on electrical inspection, electrical wiring, electrical problem diagnosis, and electrical repair can be found in the Electrical Books section of the InspectAPedia Bookstore. (courtesy of Amazon.com)
- "Electrical System Inspection Basics," Richard C. Wolcott, ASHI 8th Annual Education Conference, Boston 1985.
- "Simplified Electrical Wiring," Sears, Roebuck and Co., 15705 (F5428) Rev. 4-77 1977 [Lots of sketches of older-type service panels.]
- "How to plan and install electric wiring for homes, farms, garages, shops," Montgomery Ward Co., 83-850.
- "Electrical System Inspection Basics," Richard C. Wolcott, ASHI 8th Annual Education Conference, Boston 1985.
- "Simplified Electrical Wiring," Sears, Roebuck and Co., 15705 (F5428) Rev. 4-77 1977 [Lots of sketches of older-type service panels.]
- "How to plan and install electric wiring for homes, farms, garages, shops," Montgomery Ward Co., 83-850.
- "Home Wiring Inspection," Roswell W. Ard, Rodale's New Shelter, July/August, 1985 p. 35-40.
- "Evaluating Wiring in Older Minnesota Homes," Agricultural Extension Service, University of Minnesota, St. Paul, Minnesota 55108.
- "Electrical Systems," A Training Manual for Home Inspectors, Alfred L. Alk, American Society of Home Inspectors (ASHI), 1987, available from ASHI. [DF NOTE: I do NOT recommend this obsolete publication, though it was cited in the original Journal article as it contains unsafe inaccuracies]
- "Basic Housing Inspection," US DHEW, S352.75 U48, p.144, out of print, but is available in most state libraries.
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