Many homeowners use motion detectors for security purposes or to increase energy efficiency.
These devices can set off an alarm or switch on lights when it detects movement.
Sometimes, however, motion sensors detect objects that we don’t want them to pick up, such as a Roomba.
A Roomba can set off a motion detector. PIR, microwave, and ultrasonic sensors can mistake a Roomba for a person based on heat or motion, and they may act as the Roomba passes by. Hybrid sensors are the best option as they use multiple technologies and are less likely to cause false alarms.
The first steps to solving the problem are understanding how motion detectors work, what technology they use, and why a Roomba sets off your motion detector.
In this article, I’ll cover those topics and how you can prevent your motion detector from activating when the Roomba glides across the floor. Read on to learn more.
How Do Motion Detectors Work?
There are several different types of motion sensor technologies available.
Each has its own benefits and drawbacks regarding sensitivity and motion detection.
Motion detectors work using passive infrared technology, ultrasonic frequencies, microwave radiation, cameras, or a combination of multiple technologies.
PIR detects heat, whereas ultrasonic and microwave radiation detects movement by “bouncing” waves off of nearby moving objects.
Passive Infrared (PIR) Motion Sensors
PIR motion sensors, found in many modern security devices, are common in public spaces, such as bathrooms or office areas.
They’re popular because they use very little energy, are compact, and are relatively inexpensive.
These sensors work by sensing temperature changes using pyroelectric sensors.
Human and animal bodies emit a significant amount of heat, so the PIR picks up on that.
From there, it activates lights or signals an alarm.
For homeowners that use a Roomba, PIR technology is a good choice.
While Roombas do sometimes heat up as they move across a room, PIR sensors typically rely on a large, warm object to activate the sensors.
This means that Roombas are less likely to set off a PIR motion detector.
That said, high sensitivity settings or improper installation could cause a PIR motion sensor to pick up a Roomba’s movement.
We’ll discuss how to prevent a motion detector from picking up a Roomba later in this article.
Ultrasonic Sensors
Ultrasonic sensors use ultrasonic technology (sound frequencies higher than the human ear can hear) to detect movement.
It emits ultrasonic pulses by sending out ultrasonic waves.
These waves bounce off moving objects, disrupting the waves, either triggering an alarm or activating the lights.
These sensors are ideal for spaces where a full line of sight is not possible, such as in a stairwell or a public bathroom. Many people prefer ultrasonic sensors for triggering lights to save on energy costs.
This technology is not the best option for homes using Roombas.
They use a higher level of sensitivity and are more likely to activate from a Roomba’s movement due to interference in the sound waves.
Considering that it doesn’t use heat to detect movement, it can’t tell what the object is, only that it is moving.
Microwave Sensors
Microwaves sensors are less commonly used, especially as technology advances.
This technology covers a wider area than PIR or ultrasonic motion sensors and is more vulnerable to false alarms. Not only that, but it’s rather expensive.
This technology utilizes microwave radiation to detect motion.
It’s quite similar to a speed gun used by police officers to catch speeders.
Like the ultrasonic motion detectors, microwave sensors send out a radio frequency that reflects off of nearby moving objects. If it detects a change in frequency caused by movement, the system is activated.
Roombas are likely to set off microwave sensors due to their sensitivity and range.
Microwave sensors can even detect movement through walls, so moving a Roomba to a different room may not be enough to prevent a false trigger.
Video Motion Detection (VMD)
If you use a wireless motion detection system that utilizes webcam technology to detect movement, a Roomba is far more likely to trigger it.
Webcam sensors often utilize very little intelligence, making them sensitive to any movement, including pets, ceiling fans, or even light breezes from your home’s HVAC system.
Dual-Tech Motion Sensors
The best motion-sensing technologies on the market utilize multiple methods for detecting movement.
Also known as “hybrid motion sensors,” dual-tech motion sensors have fewer false alarms.
For example, a device may use both PIR and ultrasonic frequencies to detect movement.
The PIR might notice a temperature change in the room while the ultrasonic sensor detects a disturbance in the frequency.
Working together, these devices “decide” whether to trigger motion detection. This technology is the ideal solution for homes that use Roombas.
Why Is My Roomba Setting Off My Motion Detector?
Different elements within a home can trigger motion detection.
This includes ceiling fans, flickering lights, or curtains that move whenever the heat or air conditioner kicks on.
A Roomba, because it moves across the room, can also trigger a motion detector.
Your Roomba may set off your motion detector because the motion detector’s sensitivity is too high, it’s improperly positioned, or you’re not using the pet-friendly settings. The alarm type you’re using can also cause trouble with a robot vacuum. Dual-tech devices are best for homes using Roombas.
As it has a very small heat signature, especially compared to a human body, a Roomba shouldn’t set off a PIR motion detector.
However, some PIR systems are incredibly sensitive.
For example, ADT systems detect any heat source above -459.67°F (-273.15°C). If a Roomba heats up as it vacuums, ADTs motion detectors will notice it.
Some other reasons why your Roomba sets off your motion detector include:
- Poor installation: Poorly-planned device installation, such as placing a motion detector where it can see the entire floor space, may cause it to pick up on even slight movements, such as a pet or a Roomba.
- Improperly mounting contact sensors: If you’re using contact sensors for your motion detector, they must be placed high enough (like over a door or window) to prevent the sensors from detecting a pet or a robotic vacuum.
- Not testing the device: Always test the motion sensors to determine if it reacts to the Roomba. Let the Roomba slide across the floor, within the detection area. If it triggers the system, move on to the next section to resolve the issue.
How To Prevent a Roomba From Setting Off a Motion Detector
Now that you know why your Roomba is setting off your motion detector let’s discuss several ways to remedy the problem.
Adjust the Height
Many motion detectors recommend installation at a specific height.
For example, if you mount a motion sensor 8 feet (2.43 meters) high in the corner of a room and angle it downward, it’s going to “view” the entire room.
If it’s staring at the floor space, it’s likely to detect movement from a Roomba.
Try to adjust the height and angle of the motion sensor so that it’s aimed to keep pets and Roombas out of view.
It should view the room, starting at around three or 4 feet (1.21 m) above the floor for best results.
Use Pet-Friendly Settings
Pet-friendly settings on motion detectors do more than ignore pets – they’re also helpful in preventing the unwanted triggering of the device by a Roomba.
Most pet-friendly motion sensors have adjustable settings based on weight.
Users can calibrate the machine to ignore warm objects that are 50 pounds (22.6 kg) or less.
Sensors may also have removable clips or tabs for each weight set.
A Roomba only weighs around 9 pounds (4.08 kg), so the sensors shouldn’t pick it up, even if the sensitivity level is high.
Experiment With Sensitivity Levels
I highly recommend trying out different sensitivity levels when setting up a motion detector.
Take about a week to practice with different settings. Adjust them accordingly whenever the Roomba sets them off.
Once the Roomba no longer activates the device, you’ll know that you’ve found the ideal sensitivity.
Conclusion
Motion sensors are excellent for home security and reducing energy costs.
Sometimes, however, you can run into problems when using them, especially when utilizing smart devices like a Roomba.
Choosing the right motion sensor technology is one way to prevent a Roomba from setting off your motion detector. Dual-tech sensors are best, with PIR technology coming in as a close second.
If you’re still having issues with your motion sensors detecting a Roomba, try adjusting the position, using the pet-friendly settings, or experimenting with sensitivity levels.
