Occupancy Sensor vs Z-wave Switch

(Broderick) #1

We finally moved into a house with neutral wires, so I sold all my TCP bulbs and moved over to light switches. However, I’m not sure whether to get a simple $20 occupancy sensor light switch (not connected to ST) or a Z-wave switch ($40) with a separate motion sensor ($30). Obviously I love the idea of having everything connected to ST, but in the end, it’s $70 vs $20 and they do the same thing. I need some help deciding. Does anyone have any experience in this and can weigh in?

Zigbee wall switch with motion detector
Occupancy sensor vs motion detector: what's the difference?
(Brice; SmartRulesApp.com) #2

It depends if you want to be able to have any other control of those same lights. In my house, I have used the $20 switches you mentioned in the bathrooms, but z-wave switches on many other lights that I also want to be able to control remotely, turn on/off on a schedule, trigger with other events besides motion, etc.

(Mike Maxwell) #3

I originally did my bathrooms as standalone occupancy sensors, but have since been migrating them over to zwave switches and ST motions. The reason for this change being getting tired of dinking with the physical time settings on the standalone sensors/switches, as well as not being able to integrate control of these devices with other ST automatons that I didn’t initially consider…

(John) #4

There is a cheaper option: a PEQ motion sensor that Best Buy sells for $20, plus a Cree Connected LED for $15 at Home Depot. That makes the price much closer.

Of course that only works if the switch is controlling a single bulb. More than one and it starts to add up.

(Broderick) #5

I just sold all my connected lights, and I’m not going back, but that’s a great deal on the motion sensor, thanks! Has anybody gone with the occupancy sensors and liked them better than z-wave switch + motion sensor?

(Eric) #6

FYI the internet-connected light switch+motion sensor is great, it works surprisingly fast and reliably, until it doesn’t. I use them but I don’t trust them with essential lighting.

But the standalone occupancy/motion-wall-switch always works. So that’s what I used on the stairway lights where I don’t want anyone moving in the dark. The fancier ones have a few more settings like audible notification or dual-tech detection like ultrasonic+PIR, or microphonic+PIR - I don’t think they’ll go for $20 but you can find them for $30+ on ebay.


Non-networked occupancy sensors (light switch + sensor in a single gang box) work very well for spaces where you can feel confident that the motion will be captured by a single sensor at the light box throughout the time that the light is desired.

Bathrooms are typically small enough, but may not recognize someone in the bathtub as “present.” Stairwells work very well. Laundry rooms usually work well, depending on shape.

Kitchens can be tricky. Galley kitchens typically work fine, but L shaped kitchens or ones with a separate table area may not have enough motion by the sensor to keep the light on.

Where things tend to fall apart is larger spaces such as family rooms and living rooms. These are spaces where people may sit with limited motion for long periods of time, and it’s quite difficult to place a single sensor where it will catch someone entering the room and where they will settle.

For these kinds of spaces, it’s usually better to either have the sensor only turn the lights on but not off, or to use multiple sensors in a zone configuration. sometimes the best choice is combining ceiling sensors with entry point sensors to address these kinds of spaces. But it all increases cost, regardless of the protocol.

For these bigger spaces where more than one sensor will be needed, the sensor in the light box may be largely irrelevant to the true trigger zone. So the cost calculation can end up quite different in those cases.

@bravenel and others who use multiple motion sensors can speak more to their methods, it’s just something to keep in mind when planning.