Performance Assessment of Lighting Systems
A. Bhatia, B.E.
At one time, good
lighting simply meant enough lighting. In today's environment, ergonomic studies
attest very high importance to aesthetics, ambience, productivity and safety.
It is important to ensure that while the most appropriate equipment to meet
the lighting requirements is used, it is also the most efficient equipment of
its type. The most energy efficient lighting installations ensure that lighting
is provided only where and when it is required. This may be achieved with appropriate
design to produce either uniform general lighting or localized lighting.
The good lighting demands appropriate level of lighting, technology and design techniques to achieve maximum effectiveness whilst improving energy efficiency.
This 3- hour online course provides an approach to the performance assessment of lighting systems and the fact sheet of principle good practices.
This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
At the conclusion of this course, the student will be aware of:
This course is aimed at Students, Electrical & Control Engineers, Energy Auditors, Operational & Maintenance Personnel, Sales & Marketing personnel, and General Audience.
is important-no one doubts that. But in context to lighting, the energy conservation
decisions are normally based after productivity, safety and quality. The dollar
savings derived from energy savings alone may be small compared to the overall
value derived from more effective lighting.
This is not to say that one is exclusive of the other. Often, more effective lighting also results in lower energy consumption. The benefits of energy conservation are hidden. A large percentage of the energy input into the lighting system shows up as heat in the conditioned space, which impact the air-conditioning costs. High-efficiency lighting along with reduced air-conditioning reduces the peak electricity demand and usually raises power factor, both of which yield spare capacity on transformers. High efficiency lighting also contributes to reductions in emissions of pollutants associated with global warming, acid rain and smog.
Therefore, the objective must be to achieve the maximum lighting effectiveness with least energy consumption.
The course content is in a PDF file Performance Assessment of Lighting Systems. You need to open or download this document to study this course.
The energy consumed
by electric lighting in buildings is substantial and represents a significant
cost to the owners and occupiers of buildings. Efficient lighting systems aid
in productivity, improve the working environment and keep operating costs down.
In order to select the right light source for the job, you should consider important
performance variables such as light output (lumens), efficiency (lumens/watt
- technically referred to as "efficacy"), lamp life, and color rendering
properties measured in terms of the color rendering index (CRI).
Start with a lighting audit to evaluate the current lighting systems and assess how well the systems perform compared to state-of-the-art systems. The benchmark is lighting power density (LPD), which is expressed as watts per square foot (watts/ft2). When assessing the efficiency of a lighting installation, it is essential to consider both installed power and hours of use together. A higher installed load combined with a suitable control system to give low hours of use may result in lower energy consumption than an alternative installation with a lower installed power but poorer control.
Each application is different. Of the thousands of lamps available, fluorescent lamps are the principal light source used in industrial & commercial facilities, due to their versatility and low cost. Metal halide and high pressure sodium lamps are used in high-mounting applications, while incandescent lamps are used more in domestic applications due to very high CRI. Low pressure sodium vapor lamps provide highest efficiency (lumens/watt) but it suffers from poor CRI.
Readers are advised to the consult lighting consultant or manufactures for the most up to date information in respect of product performance and interchangeability of lamps and circuit components in view of the rapid rate of development in the lighting industry.
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.