occupancy sensors, timers, etc.

[Energy-Miser]

Greetings,
Am working on pricing for office building installation of lighting controls to cut down electric bill. The property manager wants to cut down on the on-time for lights left burning by cleaning crew, by careless tenants leaving office lights and bath lights and fans running all day, all night, etc. through some sort of automation. Has anyone done that sort of thing with combinations for example of timers, manual switches, motion or occupancy sensors, etc.? The lights are scattered in hallways, the lobby, in the many offices, and seven small bathrooms. Total office space floor is around 15,000 sq. ft. She is aiming at re-cuping the investment in one year. Thanks for your insight. Best, e/m.

 

[nakulak]

occupancy sensors in bathrooms - no problem

recouping expense of rewiring and installing contactors for building in one year - doubtful

 

[Energy-Miser]

occupancy sensors in bathrooms - no problem

recouping expense of rewiring and installing contactors for building in one year - doubtful

I know, that is a tight constraint, she may have to relax it. In addition to automation, there are three bulb T12 fixtures all over the place, which can be changed to electronic ballast T8's, and there are tons of incandescent 6" recessed cans that can be changed over to CFLs adding to the saving. e/m

 

[captaincrab55]

occupancy sensors in bathrooms - no problem

recouping expense of rewiring and installing contactors for building in one year - doubtful

I'll second that... A decent system usually takes 2 to 3 years to get a payback...

 

[Energy-Miser]

I'll second that... A decent system usually takes 2 to 3 years to get a payback...

True. I was just reading something on comparison of T12 magnetic 3-bulb fixture and equivalent T8 with electronic ballast. The difference quoted was around 45 watts for the fixture. At 12 hr / day, 365 days a year (which is heavy usage for office space and pushing it), it comes to a differnece of around 197 kwh annual. At 10 cents / kwh that is a saving of $19.7 / year. Given the material and labor for the change over, clearly one year recupe is not in the offing. Two to three is realistic IMO. e/m

 

[mdshunk]

The only projects like this I've been involved in also had lots of government grant funding and PoCo rebates. The paybacks for a refit often make no business sense. Doing it this way for a new build makes much more sense.

 

[iwire]

Usually the least expensive, fastest pay back is simply detectors that switch small areas and do away with the need for contactors and extensive re-wiring.

Also many times the power company will subsidize the price of the installation.

 

[mdshunk]

I noticed the last time I was at the grocery store, they refitted the lights in the frozen food cases with occupancy sensors. The cases were dark, until you walked down the aisle, then they popped on one by one as you walked down the aisle. Pretty neat. Made me feel like a VIP in the frozen food section. I wanted to run down the aisle to see how fast they could keep up, but I didn't.

 

[Energy-Miser]

Usually the least expensive, fastest pay back is simply detectors that switch small areas and do away with the need for contactors and extensive re-wiring.

Also many times the power company will subsidize the price of the installation.

Occupancy sensors are excellent in cutting down usage, but they are not cheap either. I hear the newer ones are pretty good at detecting occupancy and staying on for as long as needed.

 

[mdshunk]

Occupancy sensors are excellent in cutting down usage, but they are not cheap either. I hear the newer ones are pretty good at detecting occupancy and staying on for as long as needed.

They should do a hidden camera show on "occupancy sensors gone bad". It would have scenes of people in the semi-dark making arm waving movements in a vain effort to get the lights to come on. Plus, I'm sure I'm not the only one who has had to finish up his business in a public bathroom stall in the dark.

 

[iwire]

Occupancy sensors are excellent in cutting down usage, but they are not cheap either.

I disagree, they are pretty cheap.

Here is one that you can retrofit into existing fixtures in normal height ceilings

http://www.wattstopper.com/products/details.html?id=216&category=73&type=Commercial

Here another for high bay applications

http://www.wattstopper.com/products/details.html?id=207&category=76&type=Commercial

We did a warehouse over from 400 HIDs to T-5s each fixture equipped with a motion sensor, the time is kept short, like 5 minutes.

Between the reduced power consumption of the T-5s and lighting only whats needed the payback is not bad.

Besides, really, talk to the power company, they will help with these retrofits.

 

[Energy-Miser]

They should do a hidden camera show on "occupancy sensors gone bad". It would have scenes of people in the semi-dark making arm waving movements in a vain effort to get the lights to come on. Plus, I'm sure I'm not the only one who has had to finish up his business in a public bathroom stall in the dark.

Do they still have a problem or are you talking about a few years ago? One of the applications in this office space is for the bathrooms. They are fairly small sized rooms, so I am hoping that coverge is adequate, to avoid irrate office personnel calling building manager, calling us!! e/m

 

[Energy-Miser]

I disagree, they are pretty cheap.

Here is one that you can retrofit into existing fixtures in normal height ceilings

http://www.wattstopper.com/products/details.html?id=216&category=73&type=Commercial

Here another for high bay applications

http://www.wattstopper.com/products/details.html?id=207&category=76&type=Commercial

We did a warehouse over from 400 HIDs to T-5s each fixture equipped with a motion sensor, the time is kept short, like 5 minutes.

Between the reduced power consumption of the T-5s and lighting only whats needed the payback is not bad.

Besides, really, talk to the power company, they will help with these retrofits.

Thanks Bob, I took a glance at what's out there in those webs. Looks like great products. The quote I received was for wall mounted devices, if I recall right, just under $50 each. e/m

 

[aline]

They should do a hidden camera show on "occupancy sensors gone bad". It would have scenes of people in the semi-dark making arm waving movements in a vain effort to get the lights to come on. Plus, I'm sure I'm not the only one who has had to finish up his business in a public bathroom stall in the dark.

In the restrooms where I used to work the sensors operated on both motion and sound. So if you made plenty of noise while using the restroom this was not an issue. A loud cough or some other loud noise from a bodily function would turn the lights back on.

 

[Energy-Miser]

In the restrooms where I used to work the sensors operated on both motion and sound. So if you made plenty of noise while using the restroom this was not an issue. A loud cough or some other loud noise from a bodily function would turn the lights back on.

So, like a good joke, its all in the timing :smile:

 

[peter d]

In the restrooms where I used to work the sensors operated on both motion and sound. So if you made plenty of noise while using the restroom this was not an issue. A loud cough or some other loud noise from a bodily function would turn the lights back on.

LOL, IIRC the sensors we installed in Walgreens bathrooms had both the sound and motion feature.