Okay, this one has about 3 variations, depending on how you want to implement it.

The basic problem is that lights in offices are frequently left overnight after everyone's left. Why? Because it's hard to be certain you're the last one out, or you forgot since it's not part of your routine.

The first implementation of this is manual. Make it part of the standard cubicle wall that every cube has a light switch, these switches all feed back to a central control point which actually controls the light. If any of them are on the lights are on (or the zone is on, if you have more controlled lighting). Thus every person turns on their switch when they come in in the morning, and off when they leave at night. Since this is part of the routine, it will be a lot easier to remember. If they are the first one in, it turns on all the lights, if they are the last one out, it turns them all off. (Note, a delay before they go out, and a momentary switch near the entrance to turn them on for 5 minutes might be implemented if the office is to dark to get to the cube without them).

The second implementation is automatic and is tied either to the person's computer (if it's on and active, the lights stay on) or RFID access card (a reader at the entrances tracks all people in and out and turns out the lights when there's no one left). The latter would require a longer range RFID than a standard access card, so would involve some cost, but it is not impossible.

Note that neither of these requires a particularly expensive or elaborate change to the lighting control systems, just the addition of one box to the lighting circuit and as many switches or RFID tags as there are people in the office.
-- MechE, Dec 10 2009

[21 Quest], one problem with that is that most motion sensor mount where the lightswitch would be, with the result that they're useless in a divided room. They also don't work if you're sitting still or typing quietly. I've had the lights go out for lack of motion when I was working on my laptop in a conference room.
-- gisho, Dec 10 2009


When you wrote Communal, I thought of civic street lighting. :-(
-- wjt, Dec 10 2009


Motion sensor in a cubicle situation require a lot of sensors, if the cubical walls are high enough to shield people inside them.
-- MechE, Dec 10 2009


If the main switch is tied to every cubical, then the last person out and the first person out wouldn't have any light. Going through a pitch black hallway isn't exactly safe for old folks.

At any rate, I know several buildings where at least the bathroom lights are motion controlled too, so its not exactly uncommon. In fact, 'Better Off Ted' had an amusing episode a while ago in which a company had motion sensor that couldn't detect black people (hilarity ensued, of course). So pretty darn baked.
-- fredcai, Dec 11 2009


[Fred] Hence the in idea line about a 5 minute delay after the last switch goes out.

Again, the big problem with motion control is that the sensors have to see everywhere. In a shallow cube environment, that's one per row, and a full cube environment, that's one per cube (or every 2-4 cubes if the can be positioned sufficiently high). In a bathroom, the stalls are a problem. I'm not saying motion sensors are unfeasible, just more expensive than this idea (switches are cheaper than sensors).
-- MechE, Dec 11 2009


I'm with 21Q here. Most automated lighting control systems do this and many other things to help get the lights off at night while allowing users to see:

Building Time Profile where all lights are on (9-5)
Switches where necessary can act as overrides.
PIR Sensors in ceiling can act as override expiry (Switch on but no movement for 15 minutes = turn lights off)
Security/Safety paths from floor to exit (e.g. Corridor lights overrun to allow ingress/egress or security sweeps).

The problem with tying to 'computer running' status is that it is difficult to tell the difference between ON and ON and Running - If you leave the PC on then the lights stay on.
-- gnomethang, Dec 12 2009


A light switch that does nothing unless you are the last person out of the building or the first person in is an idiotic idea. How does everyone "get in the habit"? However this really illustrates a problem in large scale lighting; why would a whole bank of lights need to be on if there might, or might not, be a single person in the room?
-- WcW, Dec 12 2009



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