Energy Saving by Motion Sensors

$2-00 per corridor? Does that include cable and fitting?

Only sensors. Cable and fitting extra.

Even if it is not targeted $2, what would be minimal cost? Two lights and sensors can be bought at $ 14 at large stores , but they do not sell sensors separately.

It appears keeping lights ON with minimum wattage/light is better option in this case.

The cheapest way to automate in this case is likely using a passive infra-red sensor (or PIR), like the sort of thing that is used in security alarms.

Link

They can be powered directly off a 220V AC supply and have a separate motion-controlled contact that could be used to switch the lighting load (it appears to be small enough in this case).

Given the number you want you may be able to bulk purchase these PIR sensors from a supplier, but you will be paying more than $2.00 per corridor just for the sensors (you will need to shop around and likely go direct to a manufacturer rather than a wholesaler to get the price as low as possible).

They are fairly common and reliable however so installation, maintenance and replacement costs should be fairly low.

"Any recomendation ?"

I would recommend a review and reevaluation of your budget.

Unless, of course, this is a government sponsored project.

Lets see here... 35 floors with 4 corridors with 4 lights each at 22 watts a piece.

35 x 4 x 4 x 22 = 12,320 watts. At 10 cents a KWh if they ran 12 hours a day that would work out to around $14.78 in electricity a day.

I would hate to be someone who lives there if the building ownership is so cheap that spending $15 a day to have the lights on all night is seen as too much extra operating expense.

I agree with tcmtech.

Why not just pay someone to unscrew every other bulb on alternating weeks twice a month?

Really.

I can a appreciate being energy efficient as much as anyone but time after time I see far too many people taking it way too far when comparing it to the big picture of how they do things both for what energy is saved and how much they spent to try and save it.

I consider that if the savings adds up to less than 5% of the total average costs for any given time period and the payback time on those savings for the up front costs is more than 2 - 3 years of what it saves its probably not worth the work or effort.

but thats just me.

From experience, if you purchase the wall mounted sensor replacement switches that detect people and turn on the lights and go off in 30 seconds of zero motion, in short order you will find many of them missing. The ceiling mounted ones are less likely to be stolen - but cost more to buy and install, and they are not immune to theft either.

i would have continuous lighting that was bright enough to avoid any chance of being sued. also, there can't be no shadows.

The biggest problem with motion detection type lighting controls is that if they are used on fluorescent fixtures the bulb life is substantially reduced. So much so that any savings to be had on electricity will never come any where close to what extra expenses will be brought about on bulb replacement and overall maintenance.

When you start putting numbers to it being cheap in the name of conservation always gets spendy real fast.

There are sprung-loaded push-button switches available, which are a direct replacement for the simple light switch. They maintain a contact for a few minutes after being pushed. The switch is pneumatic, in that, when the button is pushed, it charges-up a cylinder with air. When the button is released, the air leaks away, slowly operating a piston that is pushed by the spring. When the piston reaches a point in its travel, the contact opens. Someone going into the corridor simply pushes the button. The lights come on, and after a few minutes, the contact opens and they go off.

These are not the sort of thing that one would find in B&Q or Screwfix (usual disclaimer). Go to a specialist electrical supplier or two, and make enquiries.

Oh, and the budget does look to be too tight to be effective.

I can imagine if I'm on the 35th floor, and the elevator doors open to a pitch-black corridor because no one is there to trip the lights. I wouldn't want to get out of the elevator!! Simply for the safety and security aspect of it, spending a small amount to have lights on 24/7 is easy to justify. Also, there may be building codes that dictate that this is so.

Model building codes vary by country, so this may or may not apply to the elevator lobby comment.

If I recall correctly, elevator lobby areas in USA are required by our varied building codes to be illuminated continuously, as are stairwells and areas of refuge.

This solution to a perceived problem is starting to sound impractical.

common sense should over-ride inadequate building codes

i apologize for the need to have the last comment.

Hi, I think you budget of $2.00 per corridor is a bit stingy.

What I would suggest is that you replace the lights with LED Lamps (Light Emitting Diodes) they provide the equivalent light and use less than 20% of the power that you existing lights use. You would have an instant saving of 80% of power usage and at that kind of saving you could afford to keep them on 24/7 also their life time is 40 to 50 thousand hours, so lamp replacement is reduced.

Cheers

LED lamps are quite expensive. The cheap ones are not well designed thermally, and soon fail, much like compact flourescents, they do not last, so beware.

In addition, you must get ones designed for your climate. If you have long hot spells, then they must be designed to take it. Ones made for northern climates aldo may soon die.

Then cost, LEDs light have a very high first cost, which makes them attractive to steal if they are accessable, so they need to be in highly secure fixstures = $$$

TANSTAAFL