spots, as well as allowing them to be spaced further apart at 8 to
10 feet. That also reduces the number of fixtures needed to light
the same space, multiplied by the lower energy use. The number
can be substantial.”
A strong control strategy: Rather than adjusting the lighting
controls every time one person makes a request, Houghton recommends developing a single lighting policy covering your entire
facility, creating lighting zones as needed and linking every area to
a sophisticated control system that can be tweaked remotely.
“It comes down to adopting a strategy with your team,”
Houghton says. “You can either provide controls for everyone, or
you can say, ‘We’re going to put motion sensors here, here, and in
everyone’s offices and you have to be aware.’ All the motion sensors then can talk back to a central control panel that the owner
can pull up on his phone or laptop around 6 or 7 p.m. when everyone should be gone. He can see that Joe didn’t shut off the lights
in his office, for example, and click a button to turn the lights off.
The technology of controls is growing quickly and more features
are moving into the lights themselves, which can bring substantial
savings, but you have to ask the questions.” B
Janelle Penny email@example.com is senior editor of
of power needed for spaces that genuinely need 24/7 lighting.
Consider one of these strategies.
Motion sensing: The lighting system determines when people have entered the space (with occupancy sensors) or when
they are no longer present (vacancy sensors) and turns the lighting on or off accordingly. Adding bi-level lighting allows spaces
to be dimmed to a lower level when occupancy isn’t detected,
saving energy in spaces where codes or building policy dictate
that lighting must be left on all night.
“Most spaces should be illuminated only when they’re occu-
pied, and the best way to be sure of that is motion sensors,”
explains Snyder. “Vacancy sensors save more energy than occu-
pancy sensors because occupants don’t always need to turn on
overhead lights, such as when there’s sufficient daylight, but
occupancy sensors work better in common spaces and where
needed for safety.”
Outdoor security lighting in parking lots and garages and
around the building perimeter can also benefit from motion
sensing, Snyder adds. Facade lighting can incorporate an astro-
nomical timer so the building is only illuminated when it’s more
likely to be seen.
Time sweeps: This control comes in the form of a relay panel
in the electrical closet. Circuits are fed from the distribution
panel through the relay panel, which uses an astronomical time
clock to turn circuits or relays on and off at scheduled times.
“Usually when time sweeps are used, it’s well after regular business hours just to allow anyone working over to get out of the
building,” Streit explains.
Metering: Murphy suggests that in the absence of a control
system, you can use separate meters to determine the energy
load of light fixtures.
Relamping/delamping: Replacing inefficient light sources
with high-efficiency LEDs can save a considerable amount of
money that can then be reinvested into other lighting improvements if needed. LEDs also offer the benefit of optics that place
light exactly where it should go instead of letting it spill out,
allowing you to maintain a uniform footcandle level instead of
intentionally overlighting to make sure the poorest-lit areas still
meet the minimum requirement.
“On accent lighting, we can control where the light goes better with LED so that we can take that 400W area light pointing up at the building and take that down to a 150W LED with
optics on it,” Houghton says. “The same is true with parking
lot lighting. These days, you can go from 400W to 150 or 200W
depending on the lot and code. A parking lot generally requires
0.5 footcandles for security, and you can achieve that a lot more
easily with today’s optics and not waste any light. You can also
put controls on parking lots – for example, an auto dealership
might want to keep the lights at 100% from 5 to 10 p.m. because
most people are shopping from 5 to 9. After that, you can dim
the lights down to 50%. Someone driving by sees that the lot is
still lit pretty well, but you’re saving half the money you were
This strategy also applies to interior lighting, Murphy says:
“An older space that utilizes 2x4 parabolic recessed fixtures
with three T12 lamps could use up to 120W of energy and they
might be spaced as closely as 6 feet. These could be replaced
with newer LED recessed fixtures that use 35 to 45W each and
provide even more illumination, so the amount of light output
“A high light level in the parking lot may
give an owner some satisfaction about
their lot being secure, but that’s not
necessarily the case. It’s like how people
always think their clothes aren’t clean
unless they see bubbles in the water.
Would you rather have a low-Kelvin
yellow light that prevents security cameras
from picking up images or a daylight-style LED light that saves you money and
lets cameras pick up everything?”
— Todd Houghton, Vice President of Energy Efficiency at
GenPro Energy Solutions