How Occupancy Sensors Work

What is an occupancy sensor? How does it work?

It is a motion-sensing and detecting device to control the surrounding temperature, light and ventilation system. These provide an automated system of electricity control. For example, the occupancy sensor help to save energy by automatically turning off or dimming the lights when the room is vacant or unoccupied; similarly, the sensor will switch on lights as soon as it detects someone entering the room.

Types of occupancy sensor – 

Different types of occupancy sensors based on the type of signals produced are –

· Passive infrared sensors – Passive infrared sensors, known as PIR sensors, are the most commonly used occupancy sensors. These sensors may have a range of about 35 feet, but the intensity of detection is prominent at around 15 feet. Resistant to fake and false triggering, these sensor work with a passive mechanism.

· Ultrasonic sensors – You must have heard about the concept of ultrasonic waves. These sound waves have a much higher frequency not audible to humans and animals. The ultrasonic sensors work by the sound of the reflection of light. This sensor has a wider range than the PIR sensor as it works with an active mechanism but may not be very resistant to false triggering.

· Microwave sensors – As the name suggests, the sensor works by detection through a microwave. These sensors provide a lot of versatility and work with precision. These sensors cover a much larger area and are apt for outdoor usage where other sensors cannot be used because of environmental factors.

· Acoustic sensors – These sensor work by listening to human voice or activities like tapping, typing, etc. These may be prone to false trigger as they may capture the noise on the street and work accordingly.

What is a hybrid sensor?

A hybrid sensor works with the combination of features and facilities of different sensors. For example, a combination of a PIR sensor with an ultrasonic sensor. This helps to deduct false trigger and works with the mechanism of ultrasonic waves. Moreover, it helps obtain the best output from a sensor by taking and adopting the best features of each sensor.

What are dimming sensor? How is it different from occupancy and vacancy sensors?

The dimming sensor is made from the combination of features of the occupancy and vacancy sensor. These help to dim the lights according to need. These are also used to create an effect and ambience in the home. Sometimes, these sensors also work according to the daylight environment, which means that irrespective of people entering the space, if the sensor is sensing enough daylight, it wouldn’t turn on the lights, saving electricity. The difference between the three sensors is the switching on of lights mechanism. Vacancy sensors are only designed to switch off lights, and you have to switch on lights later manually. Occupancy sensors have an automated on and off mechanism; these sensors will switch off lights when no one is in the range medium and then switch it on to detect a person entering the space, where a dimming light plays a mixed role by switching on the dim lights in someone’s presence and switching it off when no one is around. 

The choice of these lights depends upon the area of usage; dim lights can be very good for a place like the dining hall or living room where you must want to chill watching TV or doing other fun activities once in a while. However, all of these sensors help to save light and cut the usage of power by properly performing the switch-off mechanism.

How is the occupancy sensor different from the vacancy sensor?

Both the occupancy sensor and vacancy sensor work through sensors. These sensors switch off the light when the room is unoccupied or vacant, and there is no activity detection. Occupancy sensors automatically switch on the lights after sensing a human activity in the range whereas, vacancy sensors are not designed to do so. The vacancy sensor will switch off the lights but will not switch it in for you, so you definitely have to do some manual labour here. But both the sensors are useful, and the choice depends solely on an individual’s choice. 

Occupancy sensors are made for the comfort and convenience of occupants. The different models let you choose the coverage area and the different sensing system. Considering where the sensor has to be set, you can choose from the various options that suit the place best. For example, you wouldn’t want to choose a sound sensing system in a chaotic place. You would rather go for a different senor mechanism in such a place. Whereas mostly the set-up would suit an indoor place, but there are options like a microwave sensor for the outer space as well. The best places to set a sensor could be a hall, dining space or near the staircase since these areas are mostly unoccupied or can say occupied for a very short time, and the lights are switched on for no reason all day long.

Why do we need to save electricity? 

Saving electricity for the future generation is a must so that your offspring do not have to suffer from electricity shortage and loss of natural resources. It should be the moral duty and responsibility of each person to save the overuse and exploitation of resources. 

Wastage of electricity leads to the emission of toxic substances polluting the air, land and water, causing harm to the plants, animals and organisms of the land and water and even themselves. This results in the frequent occurrence of natural disasters and hazards, demolishing properties and causing loss of life. The poor people are the worst sufferers as the huts and houses demolish in no time because of landslides, earthquakes, floods. They barely have any food and shelter to sustain life.

If everyone starts saving electricity at the individual level, it can immensely contribute to the saving and conservation of many natural resources. This will reduce natural calamities and disasters that cause loss of life and property.