Occupancy Sensors

[Baje 0]

Does anyone have any experience using any?

 

I know this may not be the right forum but you guys are so helpfull

[fa chris 0]

I'm a big fan of occupancy sensors, especially in cctv applications. Put a few in a warehouse and when someone breaks in the lights come on and the camera gets an awesome picture! Gotta have the right type of ballasts/lights, if the lights take 10 minutes to warm up this won't work.

 

We mainly use them for energy savings though, keeping the lights off whenever nobody is in an area, classrooms, conference rooms, training rooms, single person bathrooms, storage areas, supply closets, etc.

 

What do you want to know about them?

[bike_rider 0]

I just put one in the garage and one in the master bedroom closet. Should have done this years ago. The only issue I ran into is that in a multi-switch setup (pass through laundry room in my case), the sensor needs to be on the load end of the switches. In my case this meant that I could not put the sensor in the place I wanted to avoid false positives. I was not going to rewire the switch boxes to solve this.

 

Other than that, they were trivial to put in, replacing an existing wall switch. Make sure you pay attention to flourecent/halogen compatibility if needed.

[Baje 0]

Hi,

 

Basically i have a client that operates a small hotel/guesthouse requesting a system that turns off the a/c (im from Barbados so you know a/c is a MUST at all times) when the guests leave the room. The two main systems that i can see are the card system (which integrates itself with the door lock system but i dont think my client may not have the budget for such a system) or the occupancy sensor which seems like the cheapest way to go. My problem is that i dont want the system to turn off the a/c while the guests are sleeping! Any way i can get around this?

 

Thanks

[fa chris 0]

There are a few different types of occupancy sensors, motion, PIR, ultrasonic, and dual tech (which is PIR & Ultrasonic together).

 

A PIR (passive infrared) occupancy sensor detects body heat. It's what Hilton (I believe) and a lot of other hotels use to control the thermostats. Just make sure it's properly mounted because I believe it needs to be line of site and the detection area isn't very large. If you use a dual tech sensor you can pick up motion with the ultrasonic outside of the range of the PIR for fuller coverage.

[Baje 0]

Thanks alot for the info..will look into it furthur

[Soundy 1]

Hi,

 

Basically i have a client that operates a small hotel/guesthouse requesting a system that turns off the a/c (im from Barbados so you know a/c is a MUST at all times) when the guests leave the room. The two main systems that i can see are the card system (which integrates itself with the door lock system but i dont think my client may not have the budget for such a system) or the occupancy sensor which seems like the cheapest way to go. My problem is that i dont want the system to turn off the a/c while the guests are sleeping! Any way i can get around this?

 

Thanks

Whether you're triggering with a sensor or from the access system, you're going to need some sort of heavy-duty relay to switch the A/C.... beyond that, it's just a matter of getting the low-power, low-voltage signal to trigger the relay, either from your sensor or from the access system - shouldn't be particularly more or less expensive either way.

 

That said, unless the access system requires a card swipe to LEAVE the room, there's not really a way to turn the A/C off based on that. And as you've already realized, using a motion sensor won't work very well when the occupants are asleep.

 

What you might do, is combine the motion/occupancy sensor with a timer, such that the sensor is bypassed at night (say, between 11pm and 7am), and only effective during the day.

 

One other thing to consider: keeping the A/C on at a low level during the day to maintain a cooler room may be more efficient in the long run than always turning it off and on, as it will have to run full-out for longer once it's turned on, to cool the room down. It might be worth investing in one of those energy-measuring devices and test both ways and see if there's a difference.

[Baje 0]

Good advice,

 

Thanks!

[tomcctv 190]

Thanks alot for the info..will look into it furthur

 

 

Hi. we do alot of hotels cctv wise. so we see alot of AC controls. PIR and the likes can Treble the hotels electric bills.

 

it is cheaper to leave an AC running than stop and start (it uses alot of power just starting up) so if it does not detect all the time the cost can go up.

 

 

there is a themostat for hotels were you take the room key card and insert it into the room stat (this is not a card reader) it just turns on the system via micro switch. entre room insert keycard AC on when they need to leave the room they need there card key so switches everything off.