Print this page Energy Efficiency – Halogen Lighting
Lee Layton, P.E.
Course Outline
The course begins with a review of the U.S lighting market in various sectors such as residential, commercial, industrial, and outdoor lighting. Chapter two covers the fundamentals of lighting including how light is transmitted, reflected, and how color is discerned. Chapter three discusses the characteristics of Halogen lamps including the theory of operation and the construction of the lamps. Chapter Four covers the applications of Halogen lamps and explains how the lamps are labeled.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
Learning Objective
After taking this course you should:
- Understand where lighting energy is consumed;
- Know the percentage of electric energy consumed by lighting;
- Know the classification of lamps;
- Know where Halogen lamps are most often used;
- Be able to explain the different theories of light propagation;
- Know how light is measured;
- Be able to explain how Halogen lamps operate;
- Know the advantages of Halogen Halide lamps;
- Be able to explain the Halogen Regenerative Cycle;
- Know the types of halogens used in the lamps;
- Know why quartz glass is needed for the envelope; and
- Understand the designators for lamp shapes and bases.
Intended Audience
This course is intended for anyone who wants to understand how Halogen lamps operate and are used in the energy markets.
Benefit to Attendees
Halogen lamps frequently used in residential and commercial applications and meet specific niche lighting markets. This course will give the reader a good understanding of how Halogen lamps operate and the types of applications that are best suited for Halogen lamps.
Course Introduction
In traditional incandescent lamps, vaporized gaseous tungsten from the filament is transported through the vapor phase and continuously deposited on the inside walls of the glass bulb. This artifact serves to blacken the inner walls of the bulb and gradually reduces light output. In order to maintain light loss at the lowest possible levels, conventional tungsten lamp filaments are housed in large bulbs having sufficient surface area to minimize the thickness of deposited tungsten that builds up over the life span of the lamp. Eventually, when a sufficient amount of tungsten is depleted, the lamp fails.
A halogen lamp, also known as a tungsten halogen or quartz lamp, is a form of incandescent lamp that has a small amount of a halogen such as iodine or bromine added. The combination of the halogen gas and the tungsten filament produces a halogen cycle chemical reaction which re-deposits evaporated tungsten back onto the filament, increasing its life and maintaining the clarity of the envelope. In order for the chemical reaction to take place, the filament needs to be hotter than that needed for incandescent bulbs. This hotter filament produces a brilliant white light and is more efficient than an incandescent lamp.
The filament is composed of ductile tungsten and located in a gas filled bulb just like a standard tungsten bulb, however the gas in a halogen bulb is at a higher pressure. The bulb must be stronger than standard glass in order to contain the high pressure. The glass bulb is typically made of fused quartz or some other special compound.
The first halogen type lamp was developed by General Electric in the 1950’s. Previously, others had tried to build halogen lamps, however they could not determine how to stop the blackening of the lamp. General Electric determined that using a small amount of iodine surrounding the tungsten filament, would allow the lamp to burn at elevated temperatures. Philips Lighting developed a lamp that used halogen bromine instead of iodine. This lamp was more efficient than iodine at the time and became the standard form of halogen lamp.
Course Content
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Energy Efficiency – Halogen Lighting
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Course Summary
Halogen lamps have the advantage of being more efficient and having longer life than the incandescent bulb. They are relatively small in size and are dimmable. The disadvantages are that they are more expensive, and burn at a much higher temperature, which could possibly be a fire hazard in certain areas.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
