Motion sensors are the beginning of every great smart home.
At some point or another, we’ve all forgotten to turn off the lights when we’ve left a room. This can become a problem particularly in spaces that don’t get visited regularly such as garages, cellars and stairways. With a KNX motion sensor, the lights will switch on and off automatically, based on detecting motion or lack of it.
The lights that turn on automatically can scare off potential intruders or help you find your way in the dark. Most KNX motion sensors offer an automatic switch-off feature that also helps reduce your energy costs. Apart from lights, you can also activate scenes, heating, ventilation, and blind systems when you enter a room.
All of this happens all by itself, without any manual operation or voice control while you’re busy doing more important things.
KNX motion sensor vs. KNX presence sensor
Recently we have written about KNX presence sensors and mentioned the difference between motion and presence sensor:
“The difference between a presence sensor and a motion sensor is that the latter detects only motion and the first detects presence, or absence of people.”
Read the full article: KNX Presence Sensor: Top 7 list and automation guide.
In general a KNX motion sensor has a smaller detection area than a presence sensor, it’s generally less sensitive and primarily designed to detect movement (e.g. an arm inside a room or a person when installed outdoors). This makes it best suited for high traffic areas such as hallways when integrated indoors or for outdoor areas in proximity to the front door.
On the other hand a KNX presence sensor is significantly more sensitive, which means that it will detect minor movement such as a hand moving or with more advanced sensors, a person breathing and warming the room with their presence. They are designed for spaces with low amounts of movement such as offices and sitting areas (dining room, living room, waiting room, …). One of the most common applications is presence-dependent lighting control.
In both cases, as you get closer to the detector it will be more sensitive to the delicate movements. The mounting height and range will also affect the sensitivity as well as the manufacturer’s specified detection area.
The ideal coverage
A sensor’s range depends on the mounting height and the area coverage of each model. Both are described in the product manual which your installer will set up in the optimal way for your use-case.
For example, here are the different detection ranges of Busch-Jaeger’s presence sensor product lines Mini, Premium and Corridor. In the image below we can see the same mounting height (3 m) and the only variable is the area coverage of each model.
It’s important to also keep in mind that bigger rooms, offices or hallways might need more than one presence sensor in order to cover the whole area.
Ideal coverage is thus based on: the number of detectors, their strength and installation heights. Here’s an example of how the detection field looks like at a sensor that’s mounted at a height of 1,10 m:
Top 10 KNX Motion Sensors
With motion sensors we can upgrade a room or an outside area with smart capabilities that react to the movements of objects. This means that devices such as lightning, heating, ventilation, AC systems, blinds, scenes and other devices can be easily and conveniently activated when a motion sensor is triggered. All by itself with no manual operation needed.
GIRA KNX Motion Sensors
GIRA is a German smart home company that offers a wide range of KNX devices whose premium design and simple, intuitive use make them truly cutting edge.
Price-wise they are at the higher end of the spectrum and currently one of the leading suppliers in the industry. In the eyes of customers, the GIRA brand is still associated with switches, with which they’ve paved their way in the KNX industry, even though they produce a wide range of products now, from sensors, lighting, climate systems and blinds, as well as door intercoms, multimedia and more.
Sensors offering imprecise or even false triggers can be a big hassle, luckily all of GIRA’s motion sensors have not one, but two integrated digital PIR sensors 6(the Cube even has three!).
The PIR sensors have a total detection range of 180°, which is composed of 2 sectors, each approx. 90°, instead of one wide sensor that covers 180°.This offers more reliable, precise and error-free motion detection.
All of Gira’s KNX motion detectors also offer adaptive delay time, which means that they analyze user behaviour to optimise the delay time (transmission delay). For example the longer the period during which people are detected in the room, the longer the delay time. And if the room is visited only briefly here and there, the motion sensors automatically reduce the delay time, thereby saving energy and conserving the light source by preventing excessive switching on and off.
From GIRA we will present three of the most popular KNX motion sensors:
- KNX motion detector with Standard top unit Standard
- KNX motion detector with top unit Komfort
- KNX motion sensor GIRA Cube
1. GIRA KNX motion sensor - Standard
This sensor can trigger lightning, heating, fans, AC system, blinds or scenes when a room or hallway is entered like any standard sensor. However if no movement is detected, they can automatically get switched off again, all that without manual switching. It offers precise motion detection and the short-term presence function can also be programmed that’s great for use in conference rooms and similar places where people are present only here and there.
2. GIRA KNX motion sensor - Komfort
The Gira’s Komfort KNX motion sensor features all of the above, plus a built-in temperature sensor that measures the room temperature. This lets you add a heating or cooling system to get triggered as well. This is especially useful for areas that aren’t occupied all the time, for example the WC room.
3. KNX motion sensor GIRA Cube
The modern look of the GIRA’s Cube sensor is what stands out at first glance, but on the inside, it’s more than just a regular motion sensor. While it works excellently at detecting movement, it has a specific focus on thermal motion and the level of brightness. It also allows you to set the angle either narrow (at 120°) or wide (at 240°). Nothing will go unnoticed with the Cube, they say at GIRA.
The Cube is upgraded with three passive infra-red (PIR) motion detectors with integrated brightness sensor, which are the main features that distinguish it from other GIRA models.
ESYLUX KNX Motion Sensor
ESYLUX is another German company that develops, manufactures and distributes KNX products. With their 25+ years of market experience, they offer first-class products that are world leaders in terms of efficiency, safety, durability and convenience, at an affordable price. We will present a basic model that offers everything you need to start integrating motion sensors.
4. MD360/8 Basic ESYLUX motion sensor
The basic model, when mounted on the ceiling, offers a basic range of 6-8 meters and a detection angle of 360°. There are no fancy features but you get a decent motion sensor that’s great to use in small rooms and passageways that also works well in low light levels or in complete darkness. It’s much more affordable than the other ones and offers the basic motion sensor functions one needs.
STEINEL KNX Motion Sensors
STEINEL has been manufacturing home and electronic devices since 1959. An electronic voltage tester for AC/DC voltage was their first product on the market, since then they’re aiming to be an innovation leader, which shows in their KNX-certified products as well.
With the largest sensor programme worldwide, STEINEL provides the "sensory organs" for KNX including PIR motion sensors. They offer both indoor and outdoor motion sensors, we will present one of each to showcase the difference in price, performance and look.
5. IS 180-2 STEINEL motion sensor
The IS 180-2 comes in black and white and with it’s slim back, easily fits any surface. It can be used both indoors and out and it’s also suitable for corner mounting. With corner wall mount, 180° angle of coverage, reach can be set up with a range of 5 - 12 m.
6. iHF 3D STEINEL motion sensor
STEINEL’S iHF 3D model has a sleek look and comes in black, white and anthracite. iHF stands for “Intelligent High-Frequency” technology that helps distinguish between objects and switches on only when needed. It’s ideal for outside usage such as home facades or larger parking areas. It has a 160° sensor with 7 m reach and apparently doesn’t get triggered by small animals or temperature changes.
MDT KNX Motion Sensor
As with all MDT’s devices their motion sensor also comes at a friendly price while still offering a lot of functions. It can be programmed to switch a KNX device on/off according to the brightness and motion. We have now presented several motion sensors priced at cca. 70€ with drastically different looks and some difference in detection ranges.
7. MDT SCN-BWM55.01 KNX Motion Sensor
This basic motion sensor offers everything you need and comes in a sleek rectangular look. The price-performance ratio is excellent as is the custom with MDT.
THEBEN KNX Motion Sensor
Founded in 1921, Theben have been pioneers in modern building technology for a century, and they also offer a wide variety of motion detectors, for indoor and outdoor use. Their PIR motion sensors reliably switch on lights on hallways, staircases, or in the garden, anywhere you might need them to turn on as soon as movement is detected.
Theben has the right motion detector for every customer’s wish: choose between wall or ceiling-mounted, between flush mounted or surface mounted and detection area range of 150° to 360°.
Here we’d like to present two, one from the lower end of the price spectrum and the other one from the higher one, to showcase what differs in both extremities.
8. Theben thePixa P360 KNX UP WH
ThePixa is not just a motion sensor, it’s also a presence sensor and it’s main benefit is the ability to restrict the detection area via app (thePixa Plug). Since it detects passive presence, not only active motion, the price is justifiably higher.
9. Theben theLuxa P300 KNX BK
TheLuxa is intended for outdoor use, both for ceilings and walls, it comes with a bigger detection range and is thus better suited for outside use.
Basalte KNX Motion Sensor
Basalte is a Belgian manufacturer that’s famous for its tastefully designed products to make each KNX smart home feel like a piece of art. They offer high-end products that have great features and never ever compromise on design. Look and feel is everything and they aren’t afraid to show theirs.
10. Basalte Auro motion sensor
Auro is the most compact full KNX motion detector on the market, with a diameter of 52mm. The inside fitting diameter is 44mm, with an installation depth of only 39mm.
It doubles as a night light due to integrated LED lights that can be set up to be turned on at full power during the day if you need it, and dimmed during the night for a gentler lighting. Auro also comes with a variety of high-end finishes to blend in with your interior or stand out as a design statement. Detection-wise it has an average detection range.
Get creative with automations
Apart from the general turning on/off of the lights, ventilation, AC and other single devices, you can use motion sensors in all sorts of creative ways. Here are just some of them to get you started:
- Alert you if your kids come home late
- Automatically ring the doorbell when someone approaches the front door
- Save energy by using motion sensor lighting in unoccupied spaces
- Notify you if pets get loose or are in rooms where they aren’t supposed to be
If you return late at night, you won’t be left searching for your keys in the dark outside your front door when equipped with a motion sensor. In public facilities, stairwells and underground car parks, a KNX motion detector also offers hygiene benefits, all the more important in these pandemic times as there’s no need to touch a switch.
One major concern that many people have are pets in a KNX smart home. Do motion sensors react to their movements and how does that affect your automations?
While you can adjust the sensitivity of your KNX motion sensor, which means more movement is required to trigger it, they still can’t tell the difference between a person walking around and a four-legged friend. This can lead to frequent false alarms.
In general, the smaller the pet the easier it is for your sensor to ignore it, however your installer will suggest the proper sensitivity and sensor position for optimal detecting. We always recommend that you test your motion detector to see if your pet or pets trigger it.If you have an issue, a pet gate can keep your pets away from the sensor when you're not home or further adjustments will be needed.
I hope you’ve been given a couple of ideas of how the prices and features vary for different motion sensors, and why to get one in the first place. If you have any questions regarding our choice or need help choosing one for your home, feel free to write to us at firstname.lastname@example.org.