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Reduction in Fixture Wattage
The input wattage of a standard magnetic ballast and two 40 watt T-12 lamps is 96 watts,
whereas the input wattage of a low power electronic ballast and two T-8 lamps is
47watts, a 50% reduction. Even more savings can be realized by delamping
(removing lamps) while maintaining comparable light levels using a high output
ballast, the stronger and higher color rendering lamps, a reflector or all of
the above. LED exit signs use less than 10% of the energy consumed by
incandescent exit signs, and CFL’s use less than 25% of the energy consumed by
incandescent bulbs. Light levels can be maintained and are in some cases better
than before the fixture retrofit or replacement.
Air
Conditioning Savings
Lighting
is a very inefficient and mostly unwanted source of heat. This heat is useful during the winter, but
during the summer it causes the air conditioning system to work harder. For
example, in Los Angeles the heat load factor is 1.15 which means that for every
100 watts in lighting input wattage saved, another 15 watts will be saved in air
conditioning, even considering the heat loss during the winter months.
Lower
Maintenance Cost
Electronic
ballasts, T-8's, CFL's, and LED's last longer than magnetic ballasts, T-12's and
incandescent lamps. After delamping there are fewer lamps to replace, and
considering that the labor cost of replacing lighting is typically greater than
the cost of the component itself, the total savings is very
significant.
Better
Output Over Life (Lumen Maintenance)
Light output
of lamps is measured in lumens. Both T8's and T12's start with about the same
lumen output, but over their lives the T12 will lose 30% to 40% of its lumens
while the T8 will lose only 5% to 10%. The graph on the right compares the lamp
lumen maintenance over lamp life of T8’s and T12’s.
Better
Quality and Color (Color Rendering Index)
The
universal scale for lighting quality is called the Color Rendering Index
(CRI). On a scale of 1 to 100 the higher
the score the better the quality. New T8's and CFL's score 85 CRI while older
fluorescent T12 lamps score just 62 CRI.
At 85 CRI T8’s are easier on the eyes and make skin tones look more
natural and paint and carpeting look newer.These new breakthrough products make
it possible to not only reduce lighting costs but to also drastically improve
lighting quality.
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Electronic Fluorescent Ballasts and
T8 Fluorescent Lamps operate at 40,000 Hz instead of the
standard 60 Hz. The higher frequency results in more efficient transfer of power
to the lamp, less heat production and more light. The lamp and ballast
combination lasts longer and is 30% to 40% more efficient. Lamps start faster,
and the health-related factors of flicker and hum are virtually eliminated. T8
lamps (1" diam.) contain higher quality phosphors which produce better quality
light than standard T12 lamps. The smaller diameter lamp also allows more light
to exit the fixture.
Compact Fluorescent Lamps
(CFL's) are
miniature versions of the fluorescent fixture with a ballast and tubes made to
resemble incandescent bulbs. CFL's combine the higher color rendering of the
rare earth phosphors (85CRI) with the compact and flexible design of
incandescent bulbs. There are screw-in replacements for most incandescent
fixtures requiring less than 25% of the energy to operate and lasting 5 to 10
times longer.
Light
Emitting Diodes (LED’s) are tiny electronic light sources
that provide an efficient low level of light for exit signs and nightlights. The
typical array of LED's consumes only 2 watts, and it will last 25 years or more.
Controls consisting of occupancy sensors,
photo sensors, dimmers and timers can reduce the hours of operation of lighting
and HVAC systems by 25% to 75%.
New
linear fluorescent fixtures, HID and compact fluorescent
fixtures containing energy efficient components are often the
best solution for older fixtures, fixtures that cannot be readily retrofitted
or for areas with insufficient light.
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