P R O G R E S S R E P O R T - Illuminating Engineering Society

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T E C H N O L O G Y
Flicker/Stroboscopic Effect. It
has been widely known that HPS
lamps will cause a stroboscopic
effect on rotating machinery.
Metal halide is not too bad when
phases are distributed properly.
Bottom Line: Fluorescent sources,
when operated at high frequency,
are unquestionably better.
Energy Consumption. Energy
is the single biggest financial
impact that a lighting fixture has
on its owner. Not the cost of the
fixture, not the cost of installation,
not the cost of maintenance.
Energy. This is why so many luminaires
get replaced by energy-efficient
products before the old
product actually dies. I won’t get
into a whole discussion on various
energy strategies: occupancy
sensing, dimming, peak-demandshedding,
etc. It would take
another article to cover these.
However, the end-user should
know that these various strategies
exist and that HID technologies
can do certain things, like dimming
and “instant-off,” although
“instant-on” is still a challenge.
Fluorescent technologies can
do dimming and instant-on pretty
well. Most of the dimming features
will cost more money initially,
and if used intelligently, pay for
themselves in time.
Every high-lumen lighting product
I’ve ever seen produces heat
and adds heat to the ambient
temperature. Heat (from anywhere)
costs the end-user money,
which can adversely affect your
overall energy calculations.
Bottom Line: This one is really
too close to call between the two
technologies. The fluorescent
products had an advantage before
electronic HID ballasts brought
new efficiencies, and HID lamps
that have been optimized for
these ballasts may swing the
energy story toward HID even
more. However, choosing a lighting
system based purely on energy
savings often results in a bad
design for visibility, and retrofitting
to a new system based only
on energy savings can result in a
poorly lighted work environment.
Installation/Maintenance.
Installing lighting equipment is
one thing. Installing it correctly
can be quite another. Luminaires
designed for aisles probably have
orientation requirements, sometimes
labeled on the fixture itself,
which state “Aisle”—except that
it’s installed the wrong way and
ends up on your punch-list.
Fluorescent luminaires, almost by
their nature, will need to be
installed in the correct orientation
and should all “line up” nicely.
Group relamping HID luminaires
can be a hard sell. But it makes the
most sense to those who value
maintained light levels. However, if
an industrial space is lighted with
six-tube fluorescent high bays,
“group relamping” should be tattooed
to a certain body part. It’s
one thing to spot-relamp luminaires
that can be reached with a
ladder, but changing one tube in a
fluorescent high bay that’s 30 ft off
the floor is lunacy. Keep that in
mind if you decide that the fluorescent
path is the one to follow on
a particular application.
Also remember two other installation
basics: physical size and
mounting details, including getting
power into the luminaire. Physical
size can affect labor hours
required to install. If the product is
too big, too heavy or just hard to
physically manage, it may take
more than one man to install.
Rigid pendant or “hook” mounting
details are nothing new, except
that if you are using luminairemounted
occupancy sensors, you
may also want to ask if there is a
lot air-movement around the fixtures.
The point being that if the
luminaires are mounted in a nonrigid
fashion, air can move them.
If an occupancy sensor “sees”
movement, it doesn’t know if the
fixture is moving, or if something
in the environment is moving; it’s
interpreted the same.
Modular or flexible wiring systems
are allowed in many areas,
and most manufacturers have the
capability to provide this option,
or at least provide “whips” for offthe-shelf
systems. They typically
Choosing a lighting system based purely on
energy savings often results in a bad design
for visibility
add more material cost but make
it up (and more) in labor.
Bottom Line: One thing is for
sure: whether it’s fluorescent or
HID, “there’s no free lunch” when
it comes to maintenance. It is
something that must be planned
or it will “bite you”... and always
at the least-opportune time.
Hopefully, this examination of
the issues has broadened your
viewpoint to some degree, or at
least helped you concentrate on
certain industrial lighting issues
and establish priorities before
making that critical selection of
technologies and products.
About the Author:
Doug Paulin, LC,
Member IESNA (1988),
is currently with lighting
rep firm Packerland
Lighting Sales, Inc., Egg
Harbor, WI. Throughout
his career, he’s
worked as an independent lighting designer
and has also held positions ranging from
product manager and marketing manager
for manufacturers including Ruud Lighting,
Lithonia Lighting, Cooper Lighting and
Thomas Day-Brite Lighting. He is a member
of several IESNA committees and also
served on the Society’s Board of Directors.
October 2005 LD+A 77