Choosing the Right Occupancy Sensor

[mstarks01]

I have been scouring the boards looking for motion/occupancy sensor options. It seems like there are lots of good options, which I had listed but the computer crashed . I don't remember them all, but the BV500 was recommended to me by the fine folks at automated outlet. I like the fact that it has a glass break built in, which is something I need anyway.

My concern is that it won't be sensitive enough for occupancy detection in a room where someone is sleeping. I'd like to use them for keeping the fan on. If I were to set a timer on the Elk that restarts every time it sees motion, which turns off after 5 minutes of no motion, is it likely to keep the fan on by detect people rolling over in bed and with general sleep movement? Also, will the ceiling fan interfere with it (I'm guessing not).

 

[sic0048]

You really need an ocupancy detector for that. You should not use an occupany for an alarm PIR either. They are two different devices with very different uses.

A regular PIR won't even keep the fan or a light on if a person is awake. It is designed to not false alarm and therefore requires a decent amount of motion before it will trip. An occupany detector is much more sensitive. To the point that it might trip when the HVAC comes on and blows a curtain, etc. So it cannot be used for alarm purposes because you would get too many false alarms.

So you might need both a PIR and a occupany detector in the bedroom. Trying to use 1 device for both functions will simply cause frustration for the whole family.

 

[ano]

I have been scouring the boards looking for motion/occupancy sensor options. It seems like there are lots of good options, which I had listed but the computer crashed . I don't remember them all, but the BV500 was recommended to me by the fine folks at automated outlet. I like the fact that it has a glass break built in, which is something I need anyway.

My concern is that it won't be sensitive enough for occupancy detection in a room where someone is sleeping. I'd like to use them for keeping the fan on. If I were to set a timer on the Elk that restarts every time it sees motion, which turns off after 5 minutes of no motion, is it likely to keep the fan on by detect people rolling over in bed and with general sleep movement? Also, will the ceiling fan interfere with it (I'm guessing not).

You really need a bed sensor for that. Unless you have a VERY VERY sensitive occupancy sensor, or make a long timeout, with sleeping people, its going to be a constant fan on fan off. Sleeping people can move very little for long periods.

 

[Kevin L]

And not for nothing, I'm a big fan of HA, but why not just turn on the fan when you go to bed and turn it off when you get up?

 

[apostolakisl]

A regular motion detector definitely will not work. I have a motion detector in my kitchen for security and used my Elk to shut the lights off after 15 minutes of no motion. Well, i can be sitting there working at my laptop and after 15 minutes the lights go out. It is not like I sit there only moving fingers either. I lean forward, backward, turn my head, etc. If you were asleep there is no way it would pick up.

 

[mstarks01]

And not for nothing, I'm a big fan of HA, but why not just turn on the fan when you go to bed and turn it off when you get up?

Well, the truth is that I really don't need it. But I think it would be nice to have.

Sometimes it starts out warm when sleeping but throughout the night the temp drops to a point where having the fan on gives a chill. So I wanted to track occupancy and temp to determine when to run the fan.

I also want to track occupancy in the living room. Presumably people would be more active there and easier to detect; unless, of course it's my wife sleeping on the couch because I snored her out of the bedroom.

 

[mstarks01]

You really need an ocupancy detector for that. You should not use an occupany for an alarm PIR either. They are two different devices with very different uses.

Will a running fan trip a true occupancy sensor (microwave or ultrasonic, presumably)?

 

[Kevin L]

I think the occupancy detection while sleeping is going to be the tough part. The temp should be easy. Have your HA sytem monitor the temp and time and then turn the fan on or off as desired. Since you're likely to be in bed each night at some point, it's not worth the trouble and pitfalls of trying to add an occupancy sensor. If you're going to be away, you could program the HA to ignore the fan control if your alarm is set in away mode.

Kevin

And not for nothing, I'm a big fan of HA, but why not just turn on the fan when you go to bed and turn it off when you get up?

Well, the truth is that I really don't need it. But I think it would be nice to have.

Sometimes it starts out warm when sleeping but throughout the night the temp drops to a point where having the fan on gives a chill. So I wanted to track occupancy and temp to determine when to run the fan.

I also want to track occupancy in the living room. Presumably people would be more active there and easier to detect; unless, of course it's my wife sleeping on the couch because I snored her out of the bedroom.

 

[RAM]

Why don't you use a motion detector to determine that someone has entered the bedroom after a certain normal bedtime (like 10:00pm) and then turn on the fan. Then monitor the temperature and if it falls below a certain desired temperature, turn off the fan. If it hasn't turned off by morning because of temperature drop turn it off the first time motion is detected after your normal wakeup time.

 

[ano]

Controlling the ceiling fan over my master bedroom bed has proven to be the most important HA task we have. In Phoenix, we have the fan running probably 8 months of the year, and when the heat turns on or AC in the summer, the temp variations really do bother my wife a lot. I have also noticed that high humidity, or lack there-of can change the desired fan temp.

To make a long-story short, I use the room thermostat, a humidity sensor, bed sensor, alarm state and time-of-day all to drive if the fan is on or off. Even then I have an override button by our bed where we can override the fan state for an interval of 90 minutes. Overall it took lots of work to get this to work great, but its yet another advantage of Home Automation, which for me is much more than about controlling things remotely.

 

[mstarks01]

I think the occupancy detection while sleeping is going to be the tough part. The temp should be easy. Have your HA sytem monitor the temp and time and then turn the fan on or off as desired. Since you're likely to be in bed each night at some point, it's not worth the trouble and pitfalls of trying to add an occupancy sensor. If you're going to be away, you could program the HA to ignore the fan control if your alarm is set in away mode.

I think you're probably right. I could also check the state of the bedroom door since I plan on wiring those up. This should cover 99% of the cases.

The living room has a stronger use case for this. What I don't know is if the fan itself will trip one of the dual-technology sensors, such that the fan would never turn off.

 

[Kevin L]

I do have a PIR motion sensor in my Family Room. I have a very large (72") fan in there. The motion sensor does not detect the movement of the fan.

I think the occupancy detection while sleeping is going to be the tough part. The temp should be easy. Have your HA sytem monitor the temp and time and then turn the fan on or off as desired. Since you're likely to be in bed each night at some point, it's not worth the trouble and pitfalls of trying to add an occupancy sensor. If you're going to be away, you could program the HA to ignore the fan control if your alarm is set in away mode.

I think you're probably right. I could also check the state of the bedroom door since I plan on wiring those up. This should cover 99% of the cases.

The living room has a stronger use case for this. What I don't know is if the fan itself will trip one of the dual-technology sensors, such that the fan would never turn off.

 

[claymahaffey]

Just use a microphone designed to pick up your snoring!