I wouldn't consider occupancy sensors switching off unexpectedly to be a
hazard if they are properly adjusted and coverage is overlapped.

Like any sensor, you will find you get flexibility proportional to the money
spent. Consider a system that has sensitivity adjustment--too sensitive and
the moving equipment will potentially keep the lights on. You probably want
to specify a light control that will allow you to set the delay so it will
re-set without shutdown after some arbitrary, non-annoying period to allow
people to leave for break without having the lights immediately shut off.
You could also specify that the control will shut down banks of lights in
delayed sequence or flash an 'imminent shutdown' light to prompt the
analyst(s) to move a bit or you could even specify a bank of lights stay off
sensor control. I believe that I would require areas containing emergency
equipment (eye wash/safety showers, fire blankets, panel boxes, etc.) be off
control. You could even equip the system with a manual, occupant-controlled,
over-ride to reduce aggravation.

I'm having a hard time understanding how the design team is expecting to
achieve an energy savings that will give them an ROI on a motion sensor
controlled system by controlling only the lights. If the room is lit by
fluorescent fixtures the start-up cycle uses more electricity than just
leaving them on...I don't know what the time period is and it probably
varies with the manufacturer but, it is probably safe to say that if the
room is going to be vacant for a half-hour it is cheaper to leave the lights
on. Might be that the motion sensors are being used to control HVAC and fume
hoods, too.

Allay your concerns by talking with the design team to determine if they
have properly accommodated the lighting requirements and have addressed
whatever scenarios you envision.

Also, I'm thinking that lack of sufficient motion in a room with multiple
occupancy would be extremely unlikely. I presume it is fairly rare to have
analysts working solo. We require solo work to be coordinated with another
analyst or building security who will perform periodic checks on that
person. Maybe you could consider that a feature...Bob's light went out,
better get the AED.

jsb

-----Original Message-----
From: DCHAS-L Discussion List [mailto:] On Behalf Of Jeskie, Kimberly B.
Sent: Monday, December 29, 2008 12:56
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: [DCHAS-L] occupancy sensors in labs

Anyone had any luck or issues with occupancy sensors for lighting in
laboratories?  I'm looking at a set of laboratory drawings where the design
team has inserted them, but it's making my flesh crawl a little thinking
about the lights going off when someone's really still.  Just wondering if
I'm being too paranoid.

Kim

Kimberly Begley Jeskie, MPH-OSHM
Operations Manager
Physical Sciences Directorate
Oak Ridge National Laboratory
(865) 574-4945

Previous post   |  Top of Page   |   Next post