Daylighting techniques like light wells, skylights, clerestory windows, and atriums can provide natural light and reduce energy usage in buildings. Various types of lighting fixtures use different light sources like incandescent, fluorescent, halogen, LED, and sodium vapor lamps. Calculating lighting needs involves factors like luminous flux, intensity, luminance, solid angle, and utilization factor to determine the number and placement of lamps required.

1. Unit II ILLUMINATION AND LIGHTING DESIGN

2. Light is electromagnetic radiation
ofa wavelength that is visible to
thehuman eye (in a range from
about380 or 400 nanometres to
about760 or 780 nm).

3. NATURAL LIGHTING
• Day lighting is the controlled admission of
natural light, direct sunlight, and diffused-
skylight into a building to reduce electric lighting
and saving energy.

4. DAY LIGHTING

5. LIGHT WELL or air shaft is an unroofed
external space provided within the
volume of a large building to allow light
and air to reach what would otherwise
be a dark or unventilated area.

6. SKYLIGHTS can provide
ventilation as well as light.
Ventilating a building with an
operable skylight releases
the hot air that naturally
accumulates near the ceiling.

7. A clerestory window is a large window or
series of small windows along the top of a
structure's wall, usually at or near the roof
line. Clerestory windows are a type of
"fenestration" or glass window placement found
in both residential and commercial construction.

8. An ATRIUM is potentially a major
source of daylight for deep plan
buildings and offers other
environmental benefits in terms of
solar gain, reduced energy losses
and natural ventilation.

9. Types of Lights or Lamps in a Lighting system

10. INCANDESCENT BULBS are standard
bulbs and many people are quite
familiar with these bulbs. These
incandescent bulbs are available in a
broad range of sizes and voltages.
An incandescent bulb glows and
produces heat when electricity passes
through the tungsten filament present
inside the bulb. The filament of this
bulb is placed either in a mixture of
nitrogen gas or in a vacuum.

11. compact fluorescent.
traditional fluorescent
A fluorescent lamp, or fluorescent tube, is a low-pressure
mercury-vapor gas-discharge lamp that uses fluorescence to
produce visible light. An electric current in the gas excites
mercury vapor, which produces short-wave ultraviolet light that
then causes a phosphor coating on the inside of the lamp to glow.
A fluorescent lamp converts
electrical energy into
useful light much more
efficiently than incandescent
lamps. The typical luminous
efficacy of fluorescent
lighting systems is 50–100
lumens per watt

12. A HALOGEN LAMP, also known as a tungsten halogen,
is an incandescent lamp consisting of a tungsten filament
sealed into a compact transparent envelope that is filled
with a mixture of an inert gas and a small amount of a
halogen such as iodine or bromine.

13. A METAL-HALIDE LAMP is an
electrical lamp that produces light by
an electric arc through a gaseous
mixture of vaporized mercury and
metal halides (compounds of
metals with bromine or iodine).

14. Light Emitting Diode
A light-emitting diode (LED) is a
semiconductor light source that emits
light when current flows through it.
Electrons in the semiconductor recombine
with electron holes, releasing energy in
the form of photons.
A NEON LAMP (also neon glow lamp) is a
miniature gas discharge lamp.
The lamp typically consists of a small glass
capsule that contains a mixture of neon
and other gases at a low pressure and two
electrodes (an anode and a cathode).

15. HIGH-INTENSITY DISCHARGE LAMPS
(HID lamps) are a type of electrical gas-
discharge lamp which produces light by means
of an electric arc between tungsten electrodes
housed inside a translucent or transparent fused
quartz or fused alumina arc tube.
A SODIUM-VAPOR LAMP is a gas-
discharge lamp that uses sodium in an
excited state to produce light at a
characteristic wavelength near 589 nm.

16. A light fixture, light fitting, or
LUMINAIRE is an electrical
device that contains an electric
lamp that provides illumination.
All light fixtures have a fixture
body and one or more lamps.

17. INDOOR LUMINAIRES

18. REFLECTANCE : the quantity of
visible and usable light reflected by
all directions and all wavelengths
when a surface is illuminated.
A color rendering index (CRI) is a
quantitative measure of the ability of
a light source to reveal the colors of
various objects faithfully in comparison
with an ideal or natural light source.

20. SOLID ANGLE -ILLUMINATION

21. Luminous flux - I is the measure of
brightness of a light source in terms of
energy being emitted
The SI unit of luminous flux is the lumen (lm).
One lumen is defined as the luminous flux of light
produced by a light source that emits one candela of
luminous intensity over a solid angle of one steradian.
Luminous intensity, the quantity
of visible light that is emitted in
unit time per unit solid angle.

22. LIGHTING CALCULATIONS
A science laboratory bulb has a mean spherical intensity of
120cd.One tenth of the total flux emitted falls at right angles
on to a surface measuring 2.5m by 4m.Calculate

26. Lumen method
A plumbing workshop measuring 24m by 20m is to have a service
luminance of 300 lux. The lamps to be used each has a luminous
flux output of 2500 lumens and the luminaries give a utilisation
factor of 0.25. The maintenance factor assumed is 0.6.Calculate the
number of lamps required and suggest a layout for them.
WORKING
Given: UF=0.25, MF= 0.6,E=300lux, F=2500 lumens, A=24 x 20 m²