An essential component in any lighting installation, microwave sensors are a key tool in the bid to ensure buildings are run as efficiently and sustainably as possible. In this article, Chris Anderson, Technical Manager at Ansell Lighting explains more about the dynamic technology and how it can help to conserve energy use across buildings of all uses and sizes.
In an era where sustainability is at the forefront of building design and operation, implementing technology that can boost energy efficiency and reduce wastage is a must. One of the most effective tools in achieving this goal when it comes to lighting are motion responsive microwave sensors, an advanced technology that provide effortless control and reduce unnecessary lighting use.
Using a principle known as the ‘Doppler Effect’ to detect movement, microwave sensors emit continuous low-level microwave signals across a designated space or ‘detection area’. These signals reflect off objects and return to the sensor, which constantly analyses the reflections for any changes in the signal pattern caused by movement. When changes are detected, the sensor activates the lighting system, providing illumination as needed.
Ideal for use in both internal and external lighting systems, microwave sensors have revolutionised the way lighting can be operated and managed, ensuring illumination only when there are people actually using a space. The adoption of more flexible and hybrid working practices has seen the popularity of microwave sensors soar, enabling buildings to respond to usage and occupancy patterns with precision.
The main advantage of this is undoubtedly reduced energy use. By ensuring lights are only on when areas are in use, microwave sensors can reduce energy consumption across building portfolios, helping organisations in turn to cut carbon and achieve sustainability targets.
This should also translate to lower energy bills and therefore significant cost savings over time. Additionally, because lighting systems are used more efficiently, there will also be less wear and tear on the infrastructure, leading to reduced maintenance costs and longer lifespans for the lighting fixtures.
Microwave sensors are also much more effective than traditional infrared sensors in environments with walls and glass. Their high sensitivity means movement can still be detected through such obstacles making them the ideal solution for offices with partitioned spaces, warehouses with stacked goods or retail stores with glass displays. They also have a much wider detection range so are an ideal option for large spaces such as car parks, open plan offices, meeting rooms and warehouses.
If microwave sensors are something you are considering installing, then placement, integration and sensitivity must all be taken into account as these factors can have a real impact on the effectiveness of the technology.
Microwave sensors should be installed at a height where they can effectively cover the desired detection area. Metals, air currents and soundwaves can all cause false triggers so placement near ceiling fans, heating vents, direct sunlight and heavy machinery should be avoided. Microwave sensors should never be installed in metal casings or in close proximity to metal products.
Integration is also a crucial consideration. Ensuring that the microwave sensor is compatible with the existing lighting system and other automation technologies will ensure seamless operation and maximise the effectiveness of the technology.
Finding the right balance in sensitivity of the sensors is also essential if false triggers are to be minimised and the system is to operate reliably. Many microwave sensors will have sensitivity settings which will require fine-tuning once installed to meet the surrounding environment and application requirements. If the sensitivity setting is high, more minor movements will be detected. A high sensitivity will also affect the detection range of the sensor, enabling it to cover a larger area. Higher sensitivity settings are therefore ideal for large, expansive spaces like warehouses, car parks, or open-plan offices.
It is worth noting though that whilst high sensitivity can improve detection, it can also increase the likelihood of false alarms if not properly calibrated. For instance, overly sensitive sensors might react to minor, non-human movements, like curtains fluttering or HVAC systems operating therefore, finding the right balance is crucial.
An ideal solution for those tasked with reducing and monitoring energy use within buildings, microwave sensors are a powerful and adaptable technology. Easy to retrofit or install as part of a newly designed system, they offer a dynamic and functional approach to lighting. They are also extremely useful within a smart lighting system, further enhancing the energy savings that can be made.
This article appeared in the October 2024 issue of Energy Manager magazine. Subscribe here.