Comprehensive Analysis of Lighting Design for Workplace Environments

This report delves into the intricacies of lighting design, examining the roles of rods and cones in human vision and how their differences impact lighting strategies for diverse tasks. It explores acceptable light levels in workplaces, considering factors such as luminance, orientation, and room configuration. The report provides examples of visual tasks and corresponding illuminance ranges. It also discusses the influence of natural light, including fenestration, and the factors affecting its availability within buildings. Furthermore, it addresses glare, differentiating between disability and discomfort glare, and suggests measures to mitigate these issues. Diagrams are included to illustrate key concepts, providing a comprehensive overview of lighting design principles for various workplace environments.

Q1. Describe how the differences between the rods and cones in the human eye affect our vision.
Explain how these differences affect lighting design for different tasks.
In human eye there are two types of receptors namely rods and cones. Rods are involved at
scotopic vision (low level) that’s why we see everything in grey shades at night. They have low
vision acuity and they are not able to see color. Cones are involved at photopic vision. They have
high vision acuity. Cones are active for fine detailed work. Cones are of three types S cones, M-
cones, L-cones. Rods are more photo pigment while cones are less. Rods have long integration
time and cones have short integration time (Guyton, Arthur & Hall 2006).
All three types of photoreceptors in retina contribute in response of the eye at high level of light
(daytime). All the tasks like wood machining, general office work, and casual seeing require
high level of light. Mostly in all these tasks contribute cone receptors. For very fine details works
like jewelry making, watch making and assembling of electronics require high level of light.
Rods, cones or mixture of rods and cones involve in visual performance of driving at night.

Q 2.Acceptable light levels are dependent on the nature of the task being undertaken. List five
distinct considerations that may influence the required light level in a workplace situation.
Explain these factors with diagrams
Adequate lighting is very important at work place for the worker. Sufficient lighting is
responsive for the good production. There are many factors that should be considered for the
required light level in a workplace.
Luminance is the factor that require for level of light. Luminance is the intensity of the light on
the surface. Factors affecting luminance are distance from the light source. The light is decreases
as the square of distance. Distance does not affect intensity of light.
Orientation is the second factor to be considers. When the surface is tilted away from the source
of light, the larger area is covered by the light. If the plane is inclined to the direction of light, the
intensity of light decreases.
Flux distribution of the luminiare is the other factor to be considered. The level of light on the
workplace is affected by the relative proportion of upward and downward light. High proportion
of downward light increases the illumination on the workplace.( McGuinness, William & Stein
1955).
Configuration of the room is other important factor. Small spaces reflected back more light on
the surfaces of walls while large rooms have little bounce lighting.
Reflectance of the room surfaces is factor to be considered while achieving required level of
light. The surrounding surfaces affect the amount of light that falls on the light. Ceiling should be
of light color to spread more light.

Q3 Explain how you would decide what light levels are required on a work surface for particular
workplaces. Give at least five examples of different visual tasks and state the range of
illuminance that is acceptable for that task
There is some factor that should be considered to gain required level of light on the different
work spaces. Luminous flux, intensity, illuminous and cd/m2 are major consideration for required
level of work (McMullan, Randall 2002).
The light spread all over the direction by a particular light source is known as luminous flux. The
quantity of the light falling on the surface is known as illuminous. Working spaces can be too
bright and too low, and these are dependent on the task to be done. Fine detailed works like
jewelry making, watch making and electronic assembling require bright work spaces. For casual
office work, cable tunnel work normal natural light is required (Gordon, Gary & Nuckolls 1995).
Task Characteristics of task Lux
Wire works in tunnel,
Parking area.
Fine details are not required 50
Office works, gardening,
shops.
Interior with adequate demand
for vision.
500
Electronics works, drawing in
offices.
Interior with moderate
demand for vision.
750
Fine detailing assembling of
electronics, drawing and
drafting, super marts
Interior with high demand for
vision.
1000
Hand sewing, very preside Interior with demand of 1500 -2000+

assembling, assembling of tiny
mechanism.
highest level for vision.
Q4. List at least five important factors that affect the amount of natural light falling on a work
surface inside a building. Using diagrams explain how this works.
Daylight inside the building is very important according to physiologically and psychologically.
Natural light is more effective source of light than the artificial light. Fenestration is the
collective term of the windows in building. Natural light is entered inside the building through
windows. The more the windows the more natural light enters the building. Big windows in
building provide deep natural light penetration. More natural light is achieved by providing many
windows. Fenestration impacts on the ease of workers; fresh air enters the building and
ventilation of air. The quality and amount of natural light inside the building is affected by many
factors. The natural light depends on the brightness of sky. The quantity of light in building also
depends on the shape, size and position of the windows in the building. The light after external
obstruction arrives at a point in a room is externally reflected component. The light after
reflecting from internal surfaces arrives the point is known as internally reflected component
(Rea 2000).
The position of sun changes the quantity of natural light. There are two types of variation
according to the sun, daily variation and seasonal variations. At sunset and sunrise, day light is
low while at solar noon, solar illumination is high. According to the seasons, sun changes its
path. In the southern hemisphere, the sun rises and sets;
To the north in winter

To the south in summer
Q5. Name and describe the two different causes of glare which may cause disability or
discomfort depending on the magnitude of the effect. With diagrams describe what measures can
be used to reduce glare in buildings
The difficulty in seeing due to the excessive and uncontrolled light is known as glare. There are
generally two type glare, discomfort glare and disability glare. Intense light sources reduced the
visibility at workspace; this glare is known as disability glare. Excessive bright sources develops
the sensation of nuisance; known as discomfort glare.
Glare can be reduced by reducing the luminance of the source. The brightness of the background
light can be reduced by tilting the windows and screening lights. Shiny surfaces cause glare so it
should be avoided.
As luminance of the surrounding area increases, glare is decreases. Light color paints should be
used on the surfaces around the workspace so that brightness of the light source does not seem so
bright.
Size of the glare source should be reduced.
If the angular displacement of light source increases, it reduces the glare problem in the building.

References
Guyton, Arthur C. & Hall, John E. (2006). Textbook of Medical Physiology. 11th edition. Elsevier
Saunders, Philadelphia, UWS Hawkesbury, 612/1.
Gordon, Gary & Nuckolls, James L. (1995). Interior Lighting for Designers. 3rd edition. [John
Wiley & Sons] New York: UWS Nirimba, 729, [28/5]
McGuinness, William J. & Stein, Benjamin (1955). Mechanical and Electrical Equipment for
Buildings. 5th edition, [John Wiley & Sons], New York.
McMullan, Randall (2002). Environmental Science in Building. 4th ed. Macmillan, Basingstoke,
Hampshire.
Rea, M.S. (2000). IESNA Lighting Handbook: Reference and Application. 9th ed. New York:
Illuminating Engineering Society of North America.