White Paper

White paper
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Integ rated Lighting Controls
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04 March 2014
4
A white paper issued by: Siemens.
© Siemens AG 2014. All right s rese rved
These questions — and others — show the importance of a
well-thought-out plan for the integration project, says Alt-
hoff. While an open protocol offers much more flexibility
than a closed protocol, there’s no guarantee th at it will work
well with other systems, so be sure to explore what you can
and can’t do to get the sy stems communicating with each
other. In other words, unless you need to come up with a
workaround because you have two existing systems that you
need to keep in place, determine how the lightin g controls
will communicate with the BA S before beginning a project to
integrate them.
"I've seen daylight harvesting components added to existing
systems that didn't communicate and ended up being very
expensive to correct,” says Althoff. “They plug in, but they
don't always play nice.”
Energy Efficiency
One of the biggest advantages of ligh ting co ntrols is energy
efficiency; the same can be said for BAS. So being able to
integrate the two can lead to increased efficiency, but there
are a few th ings facility managers need to know to maximize
that benefit.
The first is what Benya describes as on e
of the dr
iving forces
behind interest in integration. Time-of-use pricing for elec-
tricity is becoming more common; this year, Southern Cali -
fornia Edison, one of the nation’s two la rgest utilities, will
move all its cu stomers to time-of-use pricing.
What that means is that instead of electric bills being ca lcu-
lated as simply rate times kilowatt hours — with additional
charges for peak usage — rates will vary based on the time of
day. Commercial customers will have an incentive to cut or
shift as much usage as possible during the times of the day
when the rates are highest.
But there are limits on just how much electricity use can be
cut in a com mercial building during business hours. Comput-
ers have to be on, HVAC has to provide a certain level of
occupant comfort, and certain building functions such as
security and fire/life safety have to be powered.
HVAC, through the BAS, can be adjusted to use less energy
during peak times , for example, by raising te mperatu re set-
points a degree or two higher during the summer when it’s
hottest outside. But the one system that can offer
the most
fl
exibility is lighting, because it’s the one system that can be
dimmed. And, in conjunction with daylight harvesting, it can
often be turn ed off entirely during the times of high demand;
these abilities make ligh ting a good place to look for energy
efficiency, Benya says.
“The rea son lighting is so impo rtant now is that if I turn your
lights dow n 50 percent, you'll notice, but you won't freak
out,” he says. “If I turn your computer down 50 percent — I
can't. I've got to turn it off.”
The reason this matters for integrat ion is that by combining
lighting controls with BAS, facility managers can oversee all
energy use fro m a central point, as well as taking advantage
of data sha ring to push for imp roved efficiency.
Traditionally, lighting controls have been stan d-alone sys-
tems th at communicated basic in forma tion to the BAS. That’s
not necessarily going to ch ange as the systems become more
integrated; lighting controls will still continue to be a system
apart from the base BAS.
But what is changing — and will continue to chan ge — is
how the systems comm unicate and what is done with
the
da
ta that the lighting controls system shares. As lighting
components su ch as electronic ballasts and communicative
ballasts become more able to provide information, and as
systems offer greater communication with one another, it
Harvard's Fay Hous e Goe s Integrated
At Harvard University's Fay House, home of the adminis trative
offices for the Ra dcl iffe Institute for Advanced Study, a renova-
tio n proj e ct wa s used as an opportunity to overhaul the lighting,
HVAC, an d building management systems in an effort to improve
building operations.
As part of that , the lighting controls were integrated with the
BAS via BACnet , with the empha sis being on using lighting con-
trols to driv e HVAC sched ule s. The lighting controls report occu-
pancy status to the BAS, which then adjusts th e HVAC and other
building sy stem s accordingly.
"We're no t doi n g what the typical th ing would be, which is con-
trolling the lighting or turning it on or off," say s Larry Stangel,
area tech n i cal ma nager, Siemens, which provides the building's
BAS. "We're monitoring the status points , and when that thing
goes occupied, we basically tu rn all our stuff on."
To do this , the tw o sy stems need to communicate. While that
may sou nd easy, Stangel says that during the early stages of the
project, there were some failures at communicating through
BACnet that forced multiple tries at getting communication
online. While it was all eventually worked out, it showed the
importance of clear specifications early in the proce ss, Stangel
say s.
"Anytime we do sy stem integration, upfront design and commu-
nication between us, the customer and the other vendor, that's
always th e most important thing," he sa y s. "Know
what you're
go
ing to do, how you're going to achieve it, then be on the same
page wit h the vendor."