Electrical estimation and costing

1. EEE724
ELECTRICAL ESTIMATION AND COSTING
Dr Albert K. Awopone

2.  Overview of energy efficiency
 Energy efficient lighting
Objectives

3. Energy Efficiency
Energy efficiency is the
 largest,
 least expensive,
 most friendly,
 most quickly deployable,
 least visible,
 least understood,
 and most neglected way to provide energy
services.
4/17/2024 MISOF

4. Energy Conservation
 Energy conservation is the practice of decreasing the
quantity of energy use for the same quality and
quantity of Output.
 It may be achieved through efficient use, in which
case energy use is decreased while achieving a
similar outcome.
 Energy conservation also includes prevention of
misuse of energy.
Turning off a light is energy conservation, not energy
efficiency

5.  Energy conservation involves using less energy by
adjusting your behaviours and habits,
 Energy efficiency, on the hand, involves using
technology that requires less energy to perform the
same function.
 Energy-saving light bulbs, large household
appliances, smart thermostats, and smart home are
all examples of technology that can be energy
efficient
Energy Conservation vs. Energy Efficiency

6.  Simply put, energy efficiency means using less
energy to get the same job done
 Many products, homes, and buildings use more
energy than they actually need, through
inefficiencies and energy waste.
 Energy efficiency is one of the easiest ways to
eliminate energy waste and lower energy costs.
 It is also one of the most cost-effective ways to
combat climate change, clean the air we breathe,
help families meet their budgets
Energy Efficiency

7.  Anywhere that energy is used, there is an
opportunity to improve efficiency.
 Some products, like energy-efficient light bulbs,
simply use less energy to produce the same amount
of light.
 Other products don’t use energy directly, but they
improve the overall efficiency and comfort of a
house or a building (such as thermal insulation or
windows)
Examples of energy efficiency

8.  Light bulbs: An LED light bulb uses 70-90% less
energy than an incandescent light bulb, while
providing the same illumination.
Examples of energy efficiency

9.  Windows: Energy-efficient windows are made
with materials that reduce heat exchange and air
leaks, which means you don’t need as much energy
to heat or cool a space.
 Insulation: Adding more insulation to your
building keeps the warm air inside from escaping in
cold weather. In the summer, it keeps hot air out.
With good insulation, you won’t need to use as
much energy to keep your house warm in the
winter or cool in the summer.
Examples of energy efficiency

10.  Smart thermostats: These are Wi-Fi enabled
devices that control heating and cooling in your
home by learning your temperature preferences and
schedule to automatically adjust to energy-saving
temperatures when you are asleep or away.
Examples of energy efficiency

11.  Computer power management: Computers can
be set to automatically enter a low-power “sleep”
mode when not in use.
Examples of energy efficiency

12. 1. Energy efficiency protects the environment
 Most light switches and outlets pull electricity from
nearby power plants.
 These power plants typically burn fossil fuels, such
as natural gas and crude oil.
 bi product of burning fossil fuels is the release of
greenhouse gases, such as carbon dioxide, which
contribute to climate change.
 also contain other harmful air pollutants, such as
nitrogen oxides, sulfur dioxide, and particulate
matter, that lead to unhealthy air. .
Importance of energy efficiency

13. 2. Energy efficiency saves money
 By lowering energy use, energy efficiency reduces
monthly energy bills and makes energy more
affordable for businesses and families.
 Some energy-efficient products cost more to buy
than other options, but they typically save you
money over the long term.
Importance of energy efficiency

14. 3. Energy efficiency helps address energy equity
 By reducing monthly energy bills, energy efficiency
can lessen the strain of paying for energy, especially
for families with high energy burdens
 Families experiencing energy insecurity can face
the difficult choice between paying monthly energy
bills or putting food on the table.
 Energy efficiency can help households financially
and improve the health, comfort and safety of
families in their homes.
Importance of energy efficiency

15. Energy Efficient Lighting

16.  We spend about one-quarter of our electricity
budget on lighting, or more than $37 billion
annually
 Technologies developed during the past 10 years
can help us cut lighting costs 30% to 60% while
enhancing lighting quality and reducing
environmental impacts
Energy Efficient Lighting

17.  The purpose of the lighting is to serve the needs of
persons
 Quality of illumination implies that all luminances
are designed to contribute favourably to visual
performance, visual comfort, ease of seeing and
safety for specific visual task involved.
 Glare, diffusion, direction, shadows, uniformity,
color, luminance and lumenance ratios have
significant effects of visibility & should be
considered during lighting design
INTRODUCTION:

18. Light is the medium through which we can recognize
the world surrounding us
In physical words: Light is a kind of electromagnetic
radiation that consists of ripples or waves that are
propagated in an omnipresent electric and magnetic
field, and travel away from its source uniformly in
all directions unless intercepted.
WHAT IS LIGHT

19. Various forms of incandescent bodies are the source of light, and
the light emitted by such bodies depends upon their temperature.
As the temperature increases, the wavelength of the radiated energy
becomes smaller and smaller and enters into the range of the
wavelength of light.
The wavelength which can produce the sensation of light varies
from 380nm to 780nm
NATURE OF LIGHT

20.  White light emitted by the sun consists of a mixture
of various wavelengths in the visible spectrum:
NATURE OF LIGHT

21. THE FOUR BASIC LIGHTIN
QUANTITIES

22. luminous flux: The amount of light radiated per second by a light
source.Unit: lumen (lm) symbol : ()
luminous Intensity: The amount of light radiated by a light source
in a given direction. Unit: candela (cd) or (lumen/steradian)
symbol : (l)
Illuminance: The amount of light falling on a unit of surface.
Unit: lux (lux=lm/m2) symbol : (E)
Illuminance is independent of the direction from which the
luminous flux reaches the surface
luminance: The amount of light radiated by a unit of apparent
surface in a given direction
Unit: candela per m2 (cd/m2) symbol : (L)
BASIC LIGHTING QUANTITIES

23. The distribution of the light emitted by lamps is
usually controlled to some extent by means of
reflectors and translucent diffusion screens, or
even lenses.
The interior lighting schemes may be classified
as:
1. Direct lighting
2. Semi-direct lighting.
3. Semi indirect lighting.
4. Indirect lighting.
5. General lighting
Types of lighting schemes

24. 1. Direct lighting scheme is the most commonly used
lighting scheme. In this lighting scheme more than 90%
of total light flux is made to fall directly on the working
plane with the help of deep reflectors.
2. Semi-direct lighting scheme is best suited to rooms with
high ceilings where a high level of uniformly distributed
illumination is desirable. In this lighting scheme, 60 to
90% of the total luminous flux is made to fall downwards
directly with the help of semidirect reflectors, remaining
light is used to illuminate the ceiling and walls.
Types of lighting schemes

25. 3. Semi-indirect lighting scheme is mainly used for indoor
light decoration purposes. In this lighting scheme 60 to
90% of total luminous flux thrown upwards to the ceiling
for diffuse reflection and the rest reaches the working
plane directly except for some absorption by the bowls.
4. Indirect lighting scheme is mainly used for decoration
purposes in cinemas, theatres and hotels etc and also in
workshops where large machines and other obstructions
would cause troublesome shadows if direct lighting is
used. In this lighting scheme more than 90% of total
luminous flux is thrown upwards to the ceiling for diffuse
reflection by using inverted or bowl reflectors.
5. General lighting: In this scheme laps made of diffusing
glass are used which give nearly equal illumination in all
directions.
Types of lighting schemes

26. Lighting Design using dialux