Lighting – Lumens per watt
Lamp type
Lumens per watt
Incandescent bulbs
15
CFL
60
Fluorescent tube
HPSV
60 - 100
100 – 150
Metal Halide lamps
120
LPSV
183
Light intensity from sun
Diffused daylight near
window
1, 20,000 lumen/m2
500 –600 lumens / m2
Lighting purpose – General or
Visual tasking ?
•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
Lighting & Power Factors
ELECTRICAL LOADS & APPLICATION
Lighting
Incandescent lamp
Florescent lamp
Above with e-ballast
Mercury vapor lamp
Sodium vapor lamp
Induction motor unloaded to full loaded
Welding
Resistance welding
Arc welding
Induction furnace
Electrical
furnace
Arc Furnace
Resistance Furnace
POWER FACTOR
1.00
0.5 – 0.6
0.95
0.5
0.5 - 0.6
0.15 - 0.85
0.6
0.5
0.6 – 0.8
0.7 - 0.8
1.00
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
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 %
Energy Auditing
Energy Input
Useful Output
ways to enhance output
wasted output
avoidable losses
unavoidable losses
Recoverable loss Unrecoverable loss
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
Variation in Light Output and Power Consumption
Particulars
10% lower voltage
Fluorescent lamps
Light output
Decreases by 9 %
Power input
Decreases by 15 %
HPMV lamps
Light output
Decreases by 20 %
Power input
Decreases by 16 %
Mercury Blended lamps
Light output
Decreases by 24 %
Power input
Decreases by 20 %
Metal Halide lamps
10% higher voltage
Light output
Power input
HPSV lamps
Light output
Power inpu
LPSV lamps
Light output
Power input
Decreases by 30 %
Decreases by 20 %
Increases by 30 %
Increases by 20 %
Decreases by 28 %
t Decreases by 20 %
Increases by 30 %
Increases by 26 %
Decreases by 4 %
Decreases by 8 %
Decreases by 2 %
Increases by 3 %
Increases by 8 %
Increases by 8 %
Increases by 20 %
Increases by 17 %
Increases by 30 %
Increases by 20 %
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.
Use of atrium with FRP dome in the basic architecture
can eliminate the use of
electrical lights in passages of tall buildings.
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.
The most important element in a light fitting is the reflector.
They impact on how much of the lamp’s 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
reflector’s 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.
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.
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
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@gmail.com
For more details please visit my site
•
www.energymeasuretosave.com