apartment therapy changing the world, one room at a time

We could use motion detection lighting in the hallways of my condo development.

The thing about the porch (front or back) and the front door is that the lights are there as much for security as they are for actually seeing what you are doing as you are coming through, so a motion sensor isn't necessarily helpful.

I have found that putting an auto-timer on these lights so that they only have power going to them at the times when I want the light on (i.e., dusk, night, and dawn), and then switching the incandescent lights for compact fluorescent will get me the largest amount of benefit, and adding motion sensors or photocell controllers would add a minimum of additional savings.

With regards to the other areas, I've found that the motion-sensitive switches are much larger than the old switches that would be replaced, and that makes it difficult to fit them into the electrical box. You end up having to replace the entire electrical box and cut out sheetrock to fit the larger electrical box into place, and that makes it a major pain.

Still, if you can manage it, at least for bathrooms I would replace both the fan and light switches with the motion-sensitive or auto-timer style (e.g., easily switchable between 5, 10, 15, 20, 30, 45, or 60 minutes) and gang them together on the same circuit. This allows you to avoid having them on too much longer than necessary, and saves wear-n-tear on the fan as well as saving electricity.

We installed a motion sensor lightswitch in our laundry room, which was SO helpful when we'd walk in there from the garage. The cat box was in the laundry room, but the cat never activated it. Very handy item.


We also installed one over the garage door outside, again, very helpful. I had to install "covers" on the actual switches so we wouldn't turn off the power to the motion sensor!

The facilities department in the building I work installed these things all over in an attempt to be "green". They even put them on the vending machines. The only thing they managed to accomplish is the more frequent replacement of bulbs and malfunctioning vending machines.

The bulbs would burn out prematurely from the constant on and off states. Often times, if you didn't move enough or were out of the line of sight from the sensors, the lights would turn out while you were in the room. This proved to be problematic when mechanics were working on live machinery or high voltage gear. Nothing like reaching in with a tool and the lights go out on you.

Despite the protesting from a multitude of people, our facilities department proceeded as if nothing was wrong despite the fact that we had a trash compactor full of mercury filled bulbs and what ever they saved in electricity they more than negated in new bulb costs and the $75 for each sensor switch they installed.

The vending machines also had issues too. They would remain in a low power state when no one was near them. The refrigeration would remain on, but the bill and coin mechanisms would remain powered off along with the front lights of the machine. The problems became apparent when someone would walk into the room and it was like hitting the jackpot in Vegas. All the machines would empty all their change like a slot machine and then refuse to accept anything but exact change afterwords.

So I'd have to say emphatically, NO, they do not save energy nor money. It's a farce.

I have one installed in an upstairs bathroom that really only gets used when we have guests. It's handy to not have to check that the light got turned off when our guests leave. I have thought about getting three-way motion detector switches for our basement stairs, but they're so expensive that I'm not sure there'd be any cost savings.

All I can think of is the show Better Off Ted when the corporation adds sensors that detect light reflecting off skin to activate everything in the building -- lights, doors, elevators, drinking fountains -- and hilarity ensures when they discover the sensors can't "see" their black employees.