Old-style motion sensors have been around for decades, and they work very well. I have a few in my house, either built into a light switch or in a ceiling socket connected to a bare light bulb in our utility room.
The best use for an old-style motion sensor is in a room that is used periodically – like a hallway, closet, garage, etc. Places where someone enters temporarily, performs some activity, and then departs. Old-style motion sensors aren’t ideal for rooms like bedrooms, where people may not move enough for the sensor to read their motion. When that happens, the sensor assumes no one is in the room and turns off the light. Likewise a bedroom sensor may sense movement during sleep and turn on a light that should have been left off.
Philips has a motion sensor that is smarter than the old-style sensors, and solves some of these problems.
First, you can set it to operate differently depending on the time of day. For example, you can set it to do nothing if it senses movement after 9pm. That way, it won’t turn on the light if someone moves while they are sleeping.
Second, it’s easy to place the sensor anywhere in the room, because it’s battery operated. It doesn’t have to be located inside a light fixture or switch. It can be placed conveniently to capture motion, and avoid shutting off the light inadvertently.
Third, it’s connected to the Philips Hue system, which means it controls any lights that are also part of the system, even if those lights aren’t in the same room as the sensor. For example, entering a hall that leads to the kitchen can trigger the sensor, which turns on both the hall light and the kitchen lights. Or, entering a hall that leads to your bedroom can trigger the sensor, which shut off all lights in your house, except the bedroom.
Fourth, most sensors let you choose a time delay. For example, a sensor may wait 1 minute or 5 minutes or 30 minutes before it shuts off lights. If it senses motion during the delay, it sets the delay clock back to zero. But setting the delay is often a chore, and the process is hard to remember if it’s not done frequently. The Philips Hue sensor has more delay choices than an old-style motion sensor, and you choose them via an app, which couldn’t be simpler.
I put a Philips Hue Motion Sensor in my den. It is positioned to read movements in my favorite spot, and it does not read movement if someone is merely passing behind the den. I set the delay to 10 minutes, so if I leave the room the lights turn off 10 minutes later. If I am sitting still for 10 minutes, it dims the light before turning it off, so I simply move my arm and the lights will snap back to full brightness.
Having to move just to satisfy the motion sensor is a bit of a pain. It would be better if it knew I was in the room even when it didn’t sense my motion, by proximity or signal from my phone. But it’s not too bad the way it is, and I like having it.
The only improvement I would suggest, is to have the sensor controlled by Alexa. There are times when I want the den lights to be off while I watch a movie. But if I turn off the lights and move, the Motion Sensor will register movement and turn them back on. I need to manually shut off the Motion Sensor via the app. It would be nice if I could turn the Motion Sensor on/off via Alexa. Unfortunately Philips does not appear to be interested in connecting the Motion Sensor to Alexa for the time being.
All in all, I’d consider the old-style sensors to be superior for most use cases, unless your home is substantially connected via the Philips Hue system. But my den only has Hue lights, and I am very happy with the Philips Hue Motion Sensor overall.