Sensing Defines the Experience
The core promise of automatic stair lighting is "lights on as you arrive, fade as you leave." Sensing determines whether that promise holds: short range means lights trigger mid-stair; false triggers mean the whole flight stays lit when the cat walks by. Three mainstream options: PIR, microwave radar, touch/beam.
Hard Comparison of the Three
| Aspect | PIR | 5.8GHz Radar | Touch/Beam |
|---|---|---|---|
| Range | 3–5m | 3–8m adjustable | Contact/path-break |
| Coverage | 90–120° cone | 120–360° options | Fixed path |
| Penetration | Blocked by objects | Through thin wood/drywall | No |
| Temperature | Sensitivity drops in heat | Unaffected | Unaffected |
| False-trigger control | Medium (needs lux gating) | High (pet-filtering sensitivity) | Very high (deliberate) |
| Standby | μA-level | mA-level | Extremely low |
| Unit cost | Low | Medium (+USD 0.4–1.1) | Low |
| Best fit | Home duplex/budget | Homes with pets/long stairs | Handrails/specific spots |
How Homes Should Choose
Typical duplex: PIR offers the best value with lux gating and 16 animations. Pets or long staircases (>14 steps): radar, with sensitivity/height calibration filtering sub-40cm targets. Minimalist high-end interiors: handrail touch with delay-off.
Pitfall alert: cheap "radar" modules are often ultrasonic or simplified PIR with inflated range claims. Verify with a field-test video including angles and occlusion.
Hotel / Project Requirements
- Unified dimming/CCT via central control or bus (RS485/KNX) into BMS;
- Fire linkage: forced-on emergency mode via dry contact is a code requirement;
- Lifetime: LEDs and drivers rated 30,000h+ to cut room maintenance;
- Batch consistency: ±5% brightness/CCT across a floor, factory-calibrated.
FAQ
Is radar radiation harmful?
5.8GHz modules emit milliwatt-level power (far below a WiFi router), non-ionizing, compliant with GB 8702/ICNIRP limits — safe for home use.
How much standby power do stair lights draw?
Mature designs use < 0.3W per step — a 16-step flight draws ~3.5kWh/month standby; PIR duty-cycled designs drop below 1kWh.