motion detectors to turn off internal lights

andrew-b

AlwaysSomething wrote: »

I have one in the airing cupboard! I can open the door with both hands full of clothes, and the light comes on automatically.

Interesting usage ...but for that i'd use a "push-to-break" door switch on the door frame that triggers the light on when the door opens and turns off when door closes

I think the only things i'd use a PIR for inside the house is lighting in the hall/landing or to trigger an extractor fan in the bathroom. ..can't really see the need elsewhere. And kids need to learn to turn off lights when they've finished in a room! Has anyone seen the latest ad on the tv about energy saving bulbs (think it was a government one)...it seemed to me to be giving out the wrong message by saying that leaving energy saving bulbs on all night was ok!

Incidentally if you've got a cat or dog these PIRs would likely trigger and turn your light on - which is what our local cat population does with the security lights outside (they crap on my front garden too at least once a week which is pretty gross - if i find out whose cat they may get a little present through their letterbox!).

27col

The cost of these things would tend to negate any savings made by them. We had this type of lighting controls in the offices when I was in the maintenance office of a Naval Training Establishment. These were quite large offices with a lot of light fittings in them. Therefore the potential savings in energy usage were considerable. This would not be the case in a domestic setting where the loading is fairly minimal per room.
In my opinion it would make more sense to bear down on the offenders in some way. If you had this system, all it would do would be to teach them that it is all right to leave any room and not switch off the lights. This is presumably not what you had in mind.

Pyewacket338

frogglet wrote: »

One thing that you see in apartment blocks particularly in France are push switches for the lights that keep the light on for 15 minutes then it goes off. So that the hallways aren't constantly lit up, wasting electricity.
I haven't seen them over here, but someone may be able to help.

These are available from screw-fix, you can alter the time the lights come on to suit.

omelette451

frogglet wrote: »

One thing that you see in apartment blocks particularly in France are push switches for the lights that keep the light on for 15 minutes then it goes off. So that the hallways aren't constantly lit up, wasting electricity.
I haven't seen them over here, but someone may be able to help.

Pyewacket338 wrote: »

These are available from screw-fix, you can alter the time the lights come on to suit.

These are everywhere on the continent and I've wanted to get one for ages cos my sister has a real aversion to turning lights off in the corridor. Do you have the link for screw-fix, or the product name or something? I may be being a bit dim (no pun intended!) but I couldn't find them on the website.

Kiran

andrew-b wrote: »

Interesting usage ...but for that i'd use a "push-to-break" door switch on the door frame that triggers the light on when the door opens and turns off when door closes

quote]

But how do you know the light ever really turns off?? lol........... Interesting idea though. Are these readily available from say screwfix etc?

Pyewacket338

http://www.screwfix.com/prods/22146/Electrical-Supplies/Timers/Flush-Plate-2-Wire-Push-Button-Timer?cm_re=SEARCHPROMO-_-PUSH%20BUTTON%20TIMER-_-22146

They're called push button timers, page 275 in the screw-fix catalogue.

ic

Check specs of these various automated switches to ensure they are compatible with energy saving bulbs, I considered these in the past and noticed some weren't suitable for use with fluorescent lighting.

brightonman123

try to get one that lasts more than a minute- quite dangerous in dark hallways/stairwells, when you dont know where the light switches are!

(doing delivery job, many flat blocks had these auto switch off setups around..)

TimBuckTeeth

PIR sensors are best suited to certain applications such as security lighting.
They can be a nuisance if used in a lounge or bedroom as the lights will switch off and require triggering again by jumping around.
If they are triggered frequently (eg. 10 times a night) for a few minutes, then the life of the lamps will be shortened (often quite considerably), especially with fluorescent or halogen lamps.

A suitable energy saving lamp can be left on in a hallway for very little cost for convenience and to avoid stumbling around in the dark. A 20W compact fluorescent lamp will only consume 1kWh (unit) of electricity costing around 12 pence if left on 5 hours a night for 10 days. So a PIR is not economically viable, especially if the lamps require replacing more frequently.
If you have halogen lamps or standard incandescent lamps I would choose to replace them with compact fluorescent lamps rather than fit a PIR sensor.

27col

They are adjustable for quite a large range of times, from a minute up to about 15 minutes or so. We used to use them in the factory to give time to close the roller shutters and lock up. Those shown on the screwfix site are expensive. the ones that I fitted were just white plastic like a standard light switch and much cheaper.