Does Philips Hue Motion Sensor See Through Glass & Windows? (3 Ways)

Infrared vision is used widely for navigation, night vision, targeting, and surveillance. It is also used for different devices for people.

First, realize that everything like animals, humans, even inanimate objects all emit a certain amount of IR radiation. You can’t see IR, but you can use some devices to detect it.

Passive infrared sensors are electronic devices that are used in many security alarm systems to detect motion of an infrared emitting source, typically a human body. 

Does passive infrared sensor work through glass? They surely don’t work through glass. Changes in IR energy are actually not easily detected through glass. So you should know why motion sensors usually do not work through windows, which are generally insulated.

However, you have many solutions to fix if you know how to do it.

What is the Hue Motion Sensor?

This Hue motion sensor can trigger your smart lights with motion by a passive infrared system. It can also be easily installed anywhere in your home. However why it is so hard to see through glass in only a minute.

It can make your Philips Hue experience even smarter. It is completely wireless and battery-powered. Simply walk by to trigger your smart lights. Ideal for use in stairways, hallways, and middle-of-the-night wake ups. 

You also can select in the app which scene or light setting should be triggered while motion is detected. 

It is also possible to set different light settings for night and day. At night, it will turn on a gentle night light while you get out of bed. During the day, the motion sensor can trigger crisp white light to help you see better. 

So you have a question: It is so powerful, why it doesn’t work through glass. How to fix it?

Can Motion Detectors See Through Glass?

Glass has become so commonplace now that it’s easy to see right through it without a second thought. It’s in our cabinets, on your screens, in our windows, and in many of the devices, we interact with each day. So Hue motion sensor can see right through glass?

Infrared light, or infrared waves, is part of the electromagnetic spectrum. You encounter them daily but can’t see them. 

Since the primary source of infrared radiation is thermal or heat radiation, any object which has a temperature radiates in the infrared. 

You have likely seen infrared footage displaying the heat the animals emit.

One of the most helpful applications of the IR spectrum is in sensing and detection. All objects in the world give off IR radiation in the form of heat. This can be detected through electronic sensors like infrared cameras and night vision goggles. 

It is so useful in our life, however, you can’t use it to see through glass.

Infrared light is a form of electromagnetic wave consisting of longer wavelengths than that visible light. The glass and walls usually block infrared radiation.  

Can infrared light pass through glass? it totally depends on two things: 

  • What kind of glass and what coating are on it.
  • What are the specific wavelengths of IR light (Infrared has a pretty wide spectrum)

Short-Wave Infrared (SWIR) and Near infrared (NIR) will pass through the most glass, although the amount will vary depending on the specific wavelengths and the glass.

Long-Wave Infrared (LWIR) and Mid-Wave Infrared (MWIR) will be blocked by most glass. The thermal cameras use this wavelength of IR light. 

Motion sensors use passive infrared (PIR) to detect motion of infrared light sources with wavelengths ranging from 7 μm to 14 μm. Because people give off infrared radiation from 8 μm to 14 μm, this is a great sensor for detecting human motion. Two infrared detectors’ “pixels” allow your sensor to filter out changes affecting the whole sensing area such as light or weather.

Basically, glass is great at insulation and your passive infrared sensors can’t see through glass.

Why you don’t use pixel sensors that will always see through glass?

Infrared might be blocked by modern glass, but a PIR motion sensor work in the dark. The way that motion sensors detect motion has nothing to do with how dark or light it is in the immediate area. 

A PIR motion sensor works by looking for changes in infrared energy. Humans emit some amount of IR Energy, which can be detected by a PIR motion sensor. When you walk within the detection field of a PIR sensor, it will respond accordingly by sensing your infrared energy. This makes infrared great for security and safety.

You should pick the right motion sensor, do you want to buy a Hue motion sensor?

Why Would You Want your sensors to See Through Glass or Window?

More often than not, we just want to put our sensor in the window facing outside to detect the front door/backyard or mount it indoor looking out through window or glass.

Motion sensors should be important in your home security system. Lots of burglars and prospective burglars will be put off by the existence of motion sensors in your home because they can offer round the clock security. 

PIR motion sensor can’t work reliably or doesn’t work at all through glass or windows since most glasses used in modern houses today are insulated, limiting heat coming through the glass, which in return undermine movement detection.

However, we can use pixel sensors in daytime and use PIR sensors at night. You definitely want to know some methods for your sensors to see through window or glass.

Working Around the Problem

PIR motion sensors don’t work through glass, regardless of whether it is frosted or clear. That’s because it detects the changes in temperature in the space in front of it by measuring infrared signals. 

However, because glass is a heat insulator that will absorb the infrared signal used to measure the temperature regardless of it’s frosted or clear. So you can’t fix it directly. 

  • It is impossible to upgrade your PIR motion sensor.
  • It is impossible to remove your window or glass.

You have to work around this problem and you will be happy about the results.

Using Philips Hue Outdoor Motion Sensor

The Hue outdoor motion sensor is a battery-powered, weatherized outdoor sensor. It doesn’t just track motion, but also ambient light and temperature, which help you get around the problem.

This sensor is useful to add significant value and features like PIR to the Hue ecosystem. Being able to control your lights outside and it has a dusk-to-dawn feature built-in that provides users more accurate timing. 

The Outdoor Motion Sensor’s lens has a 160 degree field of view, meaning it’s able to take in pretty lots of the landscape in front of it. The lens is also designed to detect motion directly below it with an 80 degree vertical view to limit blind spots.

The Hue outdoor motion sensor can detect motion from up to 39 feet away, which is a quite longer range than the Hue indoor sensor. You can mount it and bypass the window issue totally.

With smart lighting, it is pretty easy to get a fully automated and efficient lighting solution with motion sensors. But there are some reasons you might not want to use it.

  1. You need to mount it high up if height is a problem.
  2. You would not like to mount it if you are renting.

It is a go-to solution but you are sure to want to know other easier options.

Using an Older Window Pane for Your Motion Sensors

The term smart home tech seems to cover many bases, from audio-visual experiences and home cinemas, a house that automatically responds as you move through your day (with automatic heating and lighting), to a house that you can control with either your phone or a spoken command.

The obvious downside is the extra cost and it is not appealing if you just want to get around your glass or window.

If your house’s windows are older, you probably already know they are not as energy-efficient as they could be, but it is great for PIR sensors because they come with a pane window that can be easier to see through.

If you are living in a room you have not renovated or an older apartment, it is a good idea to use your motion sensor to see through an older window pane.

You can make your sensor work the way you need, you can place it on various angles, place. 

Taking the time to plan out your motion sensor placement for your home is very important. If your motion sensors are not in locations where they work the most efficiently, your entire system may be flawed. 

If all else fails, regretfully, you can consider ditching PIR and select other methods.

Using Pixel Motion Detection

Widespread applications for motion detection are found through the surveillance industry. Pixel motion detection is useful for our needs if you don’t want to buy Hue outdoor motion sensors. 

What is the Pixel motion sensor? There is software in the motion sensor that can compare the percentage change in color and pixels from one pixel to another.  

The percentage varies according to the sensitivity level you set in the app you use to control the device. The lower you set the level in the app, the higher the number of pixels that require to change before movement is detected or recorded as clips.

These sensors are capable of motion detection through glass by using visible light as humans do, meaning they are able to see right through glass compared to PIR sensors. However, there are some weaknesses you should take care of.

Let’s take Ring Indoor Camera as an example. With its quality 1080p video footage, flexible stand, and awesome integration into the Ring ecosystem, the Ring Indoor Cam is a great budget indoor camera. You can point it outside the window to detect movement. 

Ring devices work well with Amazon Alexa, the artificial intelligence-based smart home system. You can connect Ring Indoor Cam with Amazon Alexa for hands-free home monitoring. When the Ring Indoor Cam detects movement, your Echo device will illuminate and provide an announcement, therefore you will always discover when anyone is there.

  1. You can enter the routines section inside the Alexa app.
  2. Click the “+” icon if you want to create a new routine.
  3. Enter the name you want, and then pick the “Trigger” section.
  4. Trigger the “Smart Home”, then you can choose your Ring Indoor Cam.
  5. Click “Action”, then select “Smart Home”, you will know how to change brightness and color there for your smart lights.
  6. Press save, all is done and you can turn your smart lights on and off automatically with the routine settings.

It looks perfect and fully meets your needs, but one drawback you should know about it.

Difference Between Pixel Motion Sensor and PIR Motion Sensor

PIR motion sensors do work in complete darkness because they are not reliant on using images to detect movement.

Instead of images, PIR motion sensors can detect changes in the level of received infrared. They are designed to reliably detect people, large pets, and other large warm moving objects.

Pixel-based Motion sensors need visible light, so they can’t see any movement in complete darkness. It also has big problems in heavy fog. 

If a security camera is placed behind window or glass it will be prone to glare and a whitewash picture, especially if the light conditions are bad. In this case, the picture may be too bright, unclear and the fine details doubled.

Using Floodlight Cameras

wall mounted Ring Floodlight Cam.
wall mounted Ring Floodlight Cam.

Because technology is such an integral part of our daily lives. The convenience and comfort that smart home technology provides are appealing and it embraces the Internet of Things, meaning connecting as many home appliances, devices as possible. 

The universe of smart home automation is fascinating. If you can make your home intelligent and your tiring daily tasks occur automatically with no effort, you can work around some problems with your motion sensors.

If you just want your exterior lights to come on, it might be time to invest in a floodlight camera. These floodlight cameras have a powerful high-resolution camera with horizontal viewing angles of up to 140 degrees. They can produce 2500 lumens or more of light and record high-quality video even at night.

A few Floodlight Cameras you can pick below:

  1. Arlo Pro 3 Floodlight Camera – Wireless Security
  2. Geeni Sentry Wi-Fi Wireless Smart Security Camera
  3. Ring Floodlight Camera with Echo Show 5
  4. Amcrest Floodlight Camera, Built-in Siren Alarm
  5. Victure Floodlight Camera Pro, Infrared Night Vision
  6. Ring Floodlight Camera Motion-Activated HD Security

While there are lots of options, but one of the biggest issues for security cameras is nighttime recording. Although some cameras can offer colour night images, nothing is going to beat flooding the location with artificial light to highlight intruders. Floodlight camera also works with Homekit and Alexa by a hub or a bridge.


Smart home technology is an essential part of any security system, they represent one of the greatest ways to detect intruders and other suspicious activity. 

Now you know the answer to, “How do motion sensors work?” So, provide your family peace of mind with the right option. Hopefully, this article taught you how to make your home secure. 

If you have any questions, please comment below. I will reply ASAP.

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