The best solutions for any LED measurement application! - Beriled

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outdoor lighting | TECHNOLOGY SELECTION
criteria diagram on the left we can make the
following points.
Beam control and minimization of spill
light with the compact ceramic-metalhalide
sources is almost as good as with
LEDs. LED systems enable the lowest light
spill. On the other hand, fi tted target effi -
cacies are often higher with compact HID
sources with optimized optics. HID sources
without optics will spread the light in all
directions in a spherical pattern, hence HID
scores high on all-around lighting. Th e bulky
shape of induction lamps limits the optical
performance. On the other hand, induction
scores quite high when spherical light distributions
are required, especially for the bulbshaped
induction lamps. The traditional
shape of a lamp makes such all-around light
distributions easy.
Controllability of induction technology
is good. The main reason that induction
ranks below LEDs on this aspect is due to
the lack of variable color support and spatial
control or beam pattern. Ceramic metal
_____________ __________
halide scores much lower. Nowadays, there
are dimmable metal-halide solutions available
and even some ceramic metal halides
that do not change color when dimmed. But
controllability is certainly not a strength for
HID light sources.
In terms of aesthetic value, ceramic
metal halide scores high for its sparkle
eff ect and crisp, high-quality light. Induction
and other fl uorescent sources are more
functional light sources.
Energy savings are highest for ceramic
metal halide because these light systems
have the highest efficacy available today
and because the latest compact metal-halide
lamps allow for very high optical effi ciencies.
Induction effi cacy is on par with the bulk of
LED solutions, but LED scores higher due to
its higher optical effi ciency.
Cost aspects are shown on the right diagram
in Fig. 3. Induction lighting is often
installed in locations where maintenance
costs are very high, such as tunnels. Preventative
maintenance is usually not done
in these locations, which is permitted by
the reliability and longevity of the induction
systems. Also in more accessible outdoor
installations, preventative maintenance
may not be necessary due to the low
lumen loss factors of good-quality induction
lamps. Despite the increased lifetimes
on the most recent ceramic-metal-halide
sources, preventative maintenance cycles
are still around 5 years. Th ere are luminaire
solutions on the market which use 2 or more
lamps in a fi xture, thus doubling the lifetime
for lamp replacement to 40,000 – 60,000h,
but such solutions are rare.
Luminaire lifetimes for induction and
HID is typically 20-35 years. Initial cost
of induction and HID luminaires are 1.5-3
times higher than our reference HPS.
Th e combination of energy savings, initial
cost and maintenance cost typically results in
payback times of 2-5 years for ceramic metal
halide and induction. ROI for ceramic metal
halide installations is typically earned back
continued on page 39
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