Motion Sensors Done Right: Placement, Sensitivity, and Timeout Settings
Motion sensors are the backbone of presence-based automation. But poorly placed sensors cause more frustration than convenience. After testing 14 different sensors in various locations, I have developed a reliable placement strategy that eliminates false triggers and missed detections.
Sensor Types and Where to Use Them
PIR sensors (Aqara, Hue) detect body heat movement. They work best in rooms where you move frequently – hallways, kitchens, bathrooms. They fail in offices where you sit still. For desks and couches, mmWave presence sensors (Aqara FP2) detect breathing-level motion. The price difference is significant ($12 vs $60) so use each where it makes sense.
Placement Rules
Mount PIR sensors at doorway height (2.1m) angled slightly downward. Never point them at windows – sunlight shifts cause false triggers. In hallways, mount at one end pointing along the length, not perpendicular to traffic flow. In bathrooms, mount opposite the toilet – this ensures detection whether someone is at the sink or seated.
Timeout Configuration
The single most important setting. Hallways: 30 seconds. Kitchen: 3 minutes. Bathroom: 5 minutes. Office: 10 minutes (with mmWave). Living room: 15 minutes. I arrived at these numbers after months of adjustment. Too short and lights flicker off while you are still in the room. Too long and you waste energy. Start conservative (longer) and reduce gradually.
