Lighting

1
Lighting Lumens per watt
Lamp type Lumens per watt
Incandescent bulbs 15
CFL 60
Fluorescent tube 60 - 100
HPSV 100 150
Metal Halide lamps 120
LPSV 183
Light intensity from sun 1, 20,000 lumen/m2
Diffused daylight near window 500 600 lumens / m2
2
Lighting purpose General or Visual tasking ?
3

• Tube lights in use presently in India are T12
  (40w) T8 (36W)
• T12 implies that the tube diameter is 12/8
  (33.8mm),
• T8 implies diameter of 8/8 (26mm)
• and T5 implies diameter of 5/8 (16mm).
• This means that the T5 lamp is slimmer than 36W
  slim tube
• The advantage of the T5 lamps is that due to its
  small dia
• luminaire efficiencies can be improved by about
  5.
• However, these lamps are 50mm shorter than T12
  and T8
• which implies that the existing luminaires
  cannot be used

4
Lighting Power Factors
ELECTRICAL LOADS APPLICATION ELECTRICAL LOADS APPLICATION POWER FACTOR
Lighting Incandescent lamp Florescent lamp Above with e-ballast Mercury vapor lamp Sodium vapor lamp 1.00 0.5 0.6 0.95 0.5 0.5 - 0.6
Induction motor unloaded to full loaded 0.15 - 0.85
Welding Resistance welding Arc welding Induction furnace 0.6 0.5 0.6 0.8
Electrical furnace Arc Furnace Resistance Furnace 0.7 - 0.8 1.00
5
LED panel lamps for neon bulbs

• Panel indicator lamps are used widely in
  industries for monitoring, fault indication,
  signaling, etc. Conventionally filament lamps,
  which has got the following disadvantages
• High energy consumption (15 W/lamp)
• Failure of lamps is high (Operating life less-
  10,000 hrs.
• Very sensitive to voltage fluctuations
• The LEDs have the following merits over filament
  lamps.
• Lesser power consumption (Less than 1 W/lamp)
• Withstand high voltage fluctuation in power
  supply.
• Longer operating life (more than 1,00,000 hours)
• It is recommended to install LEDs for panel at
  design stage

6
Lighting loss - examples

• Electronic ballast in place of conventional
  choke gives savings of 20
• CFL amp in place of GLS lamp saves 70
• Illumination levels fall by 20 30 due to
  collection of dust. Clean lamps fixtures
• 36 W Vs 40 W tube light saves 8 10
• Sodium vapor lamps in place of mercury vapor
  lamps for area lighting application saves up to
  40

7
Energy Auditing
8

• The Inverse Square Law
• The inverse square law defines the relationship
  between the luminance from a point source and
  distance.
• It states that the intensity of light per unit
  area is inversely proportional to the square of
  the distance from the source (essentially the
  radius).
• E Luminance, I Luminous intensity and d
  distance
• An alternate form, taken conveniently E1 d1²
  E2 d2²
• You measure 10.0 lm/m² from a light bulb at 1.0
  meter. What will the flux density be at half the
  distance?
• Soln. E1m (d2 / d1)² E2 (1.0 / 0.5)²
  10.0 40 lm/m²

9
Variation in Light Output and Power
Consumption Particulars 10 lower voltage 10
higher voltage Fluorescent lamps Light output
Decreases by 9 Increases by 8 Power input
Decreases by 15 Increases by 8 HPMV
lamps Light output Decreases by 20 Increases
by 20 Power input Decreases by 16
Increases by 17 Mercury Blended lamps Light
output Decreases by 24 Increases by 30
Power input Decreases by 20 Increases by
20 Metal Halide lamps Light output Decreases
by 30 Increases by 30 Power input
Decreases by 20 Increases by 20 HPSV
lamps Light output Decreases by 28 Increases
by 30 Power inpu t Decreases by 20
Increases by 26 LPSV lamps Light output
Decreases by 4 Decreases by 2 Power input
Decreases by 8 Increases by 3
10
Light pipe This is a reflective tube that brings
clean light from the sky into a room, These are
Aluminum tubes having sliver lining inside. One
13 light pipe can illuminate about 250 sq.ft of
floor area with an luminance of 200 lux. A 4 ft
length of light pipe of the above size provides a
daytime average of 750 watts of the emerging
technologies.
11
Use of atrium with FRP dome in the basic
architecture can eliminate the use ofelectrical
lights in passages of tall buildings.
12

• Low Loss Electromagnetic Chokes for Tube Lights
• The loss in standard electromagnetic choke of a
  tube light is likely to be 10 to 15 Watts.
• Use of low loss electromagnetic chokes can save
  about 8 to 10 Watts per tube light.
• The saving is due to the use of more copper
  low loss steel laminations in choke, leading
  to lower losses
• Many industries have implemented this measure.

13
The most important element in a light fitting is
the reflector. They impact on how much of the
lamps light reaches the area to be lit as well
as the lighting distribution pattern.
Reflectors are generally either diffuse
(painted or powder coated white finish) or
specular (polished or mirror-like). The degree
of reflectance of the reflector material and the
reflectors shape directly influence the
effectiveness and efficiency of the
fitting. Conventional diffuse reflectors have a
reflectance of 70-80 Newer high reflect anchor
semi-diffuse materials have reflectance high as
85. Conventional diffusers absorb much of the
light and scatter it rather than reflecting it to
the area required.
14
Healthy Lighting Practices

• Separate switch for different applications
  Install separate switches for smaller areas.
  Often in large buildings, dozens of lights are
  controlled by a single switch, and not all of
  them need to be on. These lights can be rewired
  into small groups of lights, fans etc.
• Best of lights. Remove excess lights. Many older
  office and warehouse buildings have more lighting
  than needed. In many areas, half the light may be
  sufficient to light the area. When removing
  excess tubes, remember to disconnect ballasts
  that serve them.
• Saving through occupancy sensors. In rooms that
  are not occupied constantly, such as conference
  rooms, lunchrooms and bathrooms, occupancy
  sensors will automatically turn lights on when
  people enter the room and off after they leave.
  Lighting accounts for 40 percent of energy used
  in office buildings.

15
PCRA MISSION OBJECTIVE
Mission - Efficient Energy Utilisation
Environmental Protection to improve Quality
of Life Objective - Promote the Ways to
Conserve Create ENERGY AWARENESS among the
Public the Industry
16
Conserve Energy Serve Nation

• www.pcra.org
• www.energymanagertraining.com
• Please go through the Govt. Website
• And you will find mine more articles on
  Industry
• Thank You - S.ASHOK,
• PCRA Faculty
• BEE certified Energy Auditor
• COIMBATORE 05.
• call - 9 4 4 3 7 - 2 0 2 2 0
• email ashok.anbesivam_at_gmail.com
• For more details
  please visit my site
• www.energymeasuretosave
  .com