TL;DR
Get business pricing on tools and workshop supplies
- Business-only prices and quantity discounts
- Tax-exempt purchasing
- Multiple users, one account, clear invoices
A comparison by The Ambient says PIR sensors are a low-cost, low-power choice for places where people pass through, while mmWave sensors can detect still occupants in rooms used for sitting or working. The trade-off is greater sensitivity and typically more setup and power needs for mmWave. There is no single best sensor: the right choice depends on how a room is used.
The Ambient has published a comparison of PIR motion sensors and mmWave presence sensors, finding that the choice depends chiefly on whether a room is used for passing through or staying still. PIR is generally the simpler, cheaper option for hallways and entrances; mmWave can detect a person who is sitting motionless, making it more suited to living rooms, offices and bathrooms where motion-only automation can switch lights off too soon.
PIR sensors detect changes in infrared energy—in practical terms, heat changes across their field of view. They respond when a warm body moves, and their relatively simple operation means they use little power; the report says battery-powered models can last a year or more between changes. They are often inexpensive, with the report putting many below $20. But a PIR sensor detects movement, not continued occupancy: if someone sits still past the routine’s timeout, it may treat the room as empty. Movement straight toward the sensor can also be harder to detect than movement across its view.
mmWave sensors use radar, commonly at 24GHz or 60GHz, and detect reflections from objects. Their sensitivity can pick up very small movements, including the rise and fall of a person’s chest while breathing. Some models also offer distance limits or room zones, and certain advanced devices can track a person’s position to trigger different automations in different parts of a room. The report gives a typical price range of $25 to $60 or more, while noting that power use is higher and mains or USB power is common.
That sensitivity can also bring false detections. The Ambient says fans, moving curtains, plants, pets or activity in a neighboring room may trigger mmWave devices, so users may need to adjust sensitivity or zones. PIR sensors can also react to pets, radiators or direct sunlight. The comparison’s practical guidance is to use PIR where people pass through and mmWave where they may remain still.
Match Sensors to Room Use
The choice affects whether a smart-home routine responds to how people actually use a room. A PIR sensor can work well for a hallway light that should come on as someone walks by, but its motion-only detection may be a poor fit for a reading chair or desk. In those settings, an mmWave sensor may keep lights on while someone is present but still.
That does not make mmWave the automatic upgrade for every room. Its ability to detect tiny movements can also mean more false triggers, more tuning and a need for a suitable power source. Buyers should weigh reliability, installation, power and cost alongside detection capability, and consider how pets, fans and room layout could affect performance.
Products Worth Considering
LG 77-Inch OLED evo C6 4K Smart TV
Philips Hue Festavia Outdoor Globe String Lights, 8 Bulbs, 22 ft
Google Nest Learning Thermostat (3rd Gen), Stainless Steel, with 3 Temperature Sensors and elago Wall Plate
As an affiliate, we earn on qualifying purchases.
How Detection Methods Differ
The comparison addresses a familiar limitation of motion-triggered automation: a sensor may turn lights off when a person stops moving, even though the room is occupied. PIR technology senses changes in heat rather than identifying a person’s continued presence. mmWave instead measures reflected radio signals, which can reveal very small movements.
The report describes both as established smart-home options, not as a newly launched product or a change in industry standards. It names the Aqara Motion Sensor P1 as an example of a typical PIR device and the Aqara FP400 as an example of a model that supports room zones. These examples illustrate features; the comparison does not establish that either is best for every buyer.
“Use PIR where people pass through and mmWave where people stay.”
— The Ambient
Performance Depends on Placement
The supplied report does not provide controlled test results comparing specific sensors, or a single measure of detection accuracy across brands. Actual performance can vary by model, placement and room conditions, including pets, furniture, fans, curtains and wall materials. Its prices and battery-life descriptions are general comparisons, not guarantees for every device.
mmWave signals may pass through some thin, non-metallic materials, according to the report, potentially detecting activity in a neighboring room. The extent depends on the material and device; the supplied material does not provide a universal range or specify how every model handles walls. Buyers should check the product’s documented capabilities and test placement rather than assume a sensor will detect only within the room it occupies.
Choose and Test by Room
Before buying, identify whether the main job is detecting someone entering or keeping an automation active while someone remains in place. For stairs, hallways, entrances and utility rooms, a PIR unit may offer a simple, low-power fit. For living rooms, desks, bathrooms or bedrooms, mmWave may better address periods of stillness, if its sensitivity and power requirements suit the setup.
After installation, test the sensor with the room in normal use. Check whether it detects the intended area, whether pets or moving objects cause unwanted triggers, and whether light routines time out appropriately. For mmWave, adjust available sensitivity and zone settings where needed. The source provides no specific product launch or follow-up date; the practical next step for buyers is to compare individual models and verify their compatibility with existing smart-home systems.
Key Questions
Which sensor is better for a hallway?
PIR is generally the better fit for a hallway because people usually move through it. Its low power use and simple setup can also suit battery-powered installations.
Can mmWave detect someone sitting still?
Yes. The report says mmWave can detect very small movements, including breathing, so it can register a person who is present but not visibly moving.
Can mmWave sensors detect movement through walls?
The report says mmWave may pass through some thin, non-metallic materials, potentially picking up activity in a neighboring room. Performance depends on the material and device, so check the specific model rather than assuming a fixed range.
Are PIR sensors cheaper and easier to power?
Generally, yes. The comparison describes PIR models as low-power and often priced below $20, while mmWave models commonly cost $25 to $60 or more and may use mains or USB power. Prices and power requirements vary by product.
Can either sensor be triggered by pets?
Yes. The report lists pets among possible false triggers for both types. Placement matters for PIR, while mmWave may also respond to other small movements, such as fans or curtains.
Source: the-ambient.com
