Introduction to Occupancy Sensor, Working, Features, Types & Application

Occupancy sensors use the detection of motion to show a person’s existence. They are also used for turning on lights when anyone walks in the room, for temperature adjustment, or for HVAC system ventilation. Here we will discuss the features working and other factors of the Occupancy Sensor. So let’s get started with Introduction to Occupancy Sensor.

What Are Occupancy Sensors?

• The occupancy sensor is an indoor module that is used to detect the existence of any person. Its main uses are adjustment of lights, temperature, and ventilation system if there are any people.
• This sensor uses ultrasound, infrared, microwaves, and some different technologies for working. It is normally part of PIR sensors, keycard locks of hotels, and smart meters.
• Its main features that are essential for use are low energy usage and automatic control features.

How do occupancy sensors work?

• Occupancy sensors provide automatic operation during installation with the use of different techniques such as infrared, ultrasonic, radar, or microvibration.
• PIR sensors detect head differences with the use of the pyroelectric sensor. The heat released by humans and their existence is detected with sensors by measuring heat differences from static locations such as walls where sensors connect.
• Environmental sensors that measure temperature, humidity, and carbon dioxide are part of occupancy sensor operation since the changes in environment detection result from the body’s natural emission process.
• The occupancy sensors that work with the use of ultrasonic technology transmit sound waves with high frequency and measure their reflection. The changes in reflection pattern to transmitted pattern human detection measured.

What Are the Different Types of Occupancy Sensors?

PIR sensors

• These sensors work based on a head difference detection process and measure infrared radiation. The device comes with a pyroelectric sensor that detects the existence of an object that radiates a temperature difference from the background temperature difference, like the room temperature of the wall.

Environmental sensors

• Humidity, temperature, and CO2 sensors that detect environmental changes if there is any person in their range.

Ultrasonic sensors

• These sensors are like the radar and work based on the Doppler shift principle. The ultrasonic sensors release high-frequency sound waves, and then the reflected pattern of the wave is checked. If there are changes in the reflected pattern, it means there is any person in range of the wave, and the light connected will turn on. If there are no changes in the reflected pattern of waves, that means no one in range of waves and lights are off.

Microwave sensors

• These switches are like ultrasonic sensors, and their working is also based on Doppler shift. These sensors transmit high-frequency microwaves and then reflect patterns checked. If there are changes in the reflected pattern, it means there is a person who exists in a range of waves, and a result lights on. If there are no changes in the reflected wave pattern, it means there is no one in a range of waves. The detection power of microwave sensors is higher as compared to other types of sensors.

How Do Optical Sensors Collect Data?

• Optical sensors produce low-resolution images of spaces on devices. Then images are transformed into 0s and 1s with the use of AI techniques. This image was removed and not saved in databases; just its 0s and 1s are sent to the processing system.
• Suppose that we have installed occupancy sensors connected to the desk booking system of our company. The 0 means the desk is vacant, and 1 shows there is someone.

Advantages of Occupancy Sensors

Energy Efficiency:

• The main benefit of these sensors is that they have features to minimize energy use. By turning off lights or setting the HVAC system when there is no one, the sensor reduces the use of manual control and avoids any extra energy use.

Lost Cost:

• The use of low energy is automatically converted into cost savings for offices and buildings. The use of occupancy sensors resulted in reduced bills, and it is beneficial for longer use.

Automation:

• There is no way to control the occupant sensor manually for lights and the HVAC system. The automation of these sensors makes sure that the light gets on when anyone goes into the room and gets off when they leave the room, providing convenience and minimizing the chances of human negligence.

Lifespan of Equipment:

• By avoiding extra uses, these sensors also increase the working life of lights and HVAC devices. The use for low only when needed has less wear and tear and also saves maintenance and replacement costs.

Occupancy Sensors vs Motion Sensors

How Do Motion Sensors Work?

• Motion sensors work with the use of infrared energy, radar waves, and other waves for the detection of any person or object in the range of the wave. The emitter releases waves in certain areas, and if anyone is in range of these waves, the echo response effect indicates the existence of anyone.
• As a result, the sensor activates to send data to the related receiver for action. There are beam and photoelectric motion sensors, and they work by focusing beam energy transmission between the sensor and emitter.
• If there is any object between the traveling energy beam and the result sensor, it will trigger and show the occupant of the person.

How Do Occupancy Sensors Work?

• The working of occupancy sensors is the same in some conditions for motion sensors but has many differences. The occupancy sensors work with the use of infrared energy but do not detect the motion of a person, but they find the existence of a person or any other thing.
• This sensor comes with pre-set weight and size features and avoids any unnecessary activation and alarm triggering. Suppose there is the setting of a person’s motion detection by moving a chair or desk can trigger sensors that will provide incorrect data.

Applications of Occupancy Sensors

Commercial Buildings:

• These sensors are used in buildings, offices, restrooms, and common areas, which help to set lights and HVAC systems according to occupancy patterns.

Residential Buildings:

• It is also used at homes for controlling room lights that are not commonly used, like lights in living rooms, kitchens, and bedrooms. It helps to turn on lights when they are in use and helps to save energy and bills.

Educational Institutions:

• In schools, colleges, libraries, and hallways, use these sensors for effective use of energy. Lights can turn off when there is no one in these places.

Retail Stores:

• These sensors are used for controlling light and climate control systems at different parts of retail stores, setting the environment for customer existence. It helps to increase energy efficiency and make the best shopping experience.

Alternatives to Occupancy Sensors

Either occupant sensors are a cost-effective solution and can easily be installed. But it has some limited features, and they can detect only a person’s existence or not exist.

Occupancy sensors do not have details for occupancy level or number of people in that room.

There are many latest sensors, such as stereo cameras or infrared sensors, that exist that provide more details but are high-cost options.

In buildings, cameras are connected for security purposes. Intelligent video analysis software can provide details about the number of people in a room.

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