Sandy Damm, managing director at Sontay, explains why there is value in installing occupancy and light level sensors throughout a commercial building.
When you get up from your desk and venture into a meeting room or take a trip to the kitchen, what’s the one thing that helps guide you all the way? You may not notice it all the time but there will always be lights getting you from A to B. In commercial buildings, lighting is the one resource that is absolutely everywhere. It is vitally important but also has a huge impact on energy efficiency or in many cases inefficiency of a commercial building.
According to the Carbon Trust, up to 40% of a building's electricity use is accounted for by lighting, which can mean a lot of wasted energy if the lighting is left on unnecessarily. In its Lighting: Bright ideas for efficient illumination* document, the Carbon Trust goes on to say that the right levels and quality of light can improve the alertness and accuracy of those working in a space.
Simply upgrading the lighting scheme to efficient light sources is an obvious way to save energy and reduce costs, for instance, replacing legacy light sources with LED technology can reduce lighting energy costs by up to 70%.
However, that is not the end of the story. You may install efficient lighting but if all the lights are left running 24/7 then you are not maximising the potential energy and cost savings.
This is why it is important to install light level and occupancy sensors throughout the building as well. They can bring added benefits not only in terms of energy savings but also operational efficiencies.
Let’s take a look at light level sensors first. It has been estimated by the Carbon Trust that by adjusting the artificial light sources within a room to correlate to the amount of natural daylight, it can reduce electricity consumption by up to 40%. An impressive figure and all light level sensors are doing is monitoring the natural light entering a room and reducing the amount of artificial light accordingly. This can be done via dimming or disabling lighting and is known as daylight harvesting. By making the most of natural daylight, you are not only able to make energy reductions but can also create comfortable spaces for people to work in.
When installing light level sensors, you can decide to control the ambient daylight or monitor both the ambient light and the artificial light.
Moving on to occupancy sensors, these work by detecting motion within a room which triggers the lighting. These sensors will detect movements or presence, normally emitted by a person entering a space, and then turn on the lighting. Occupancy devices, such as the Sontay OC range, most commonly use passive infra-red (PIR) sensors that detect infrared radiation from all objects that emit heat. By dimming or switching off lighting when there is nobody in a room, occupancy sensors can reduce electricity use by 30%.
As well as saving energy, intelligent sensors can collect valuable data about the operation of a building. Sensors can measure, analyse and evaluate all sorts of building performance data and make this information available to the control system. By pulling together this information and using it to determine the actions of connected devices, we can create a smarter system able to adapt to the conditions of a building. With occupancy sensors installed throughout a building we are in a great position to understand about the presence, movement and patterns of occupants.
The data the sensors collect can then be turned into meaningful information to empower owners and facilities managers to adapt the operation of their building to maximise energy efficiency. With phase two of the Energy Saving Opportunity Scheme (ESOS) currently underway and a deadline of 5th December 2019, there is a requirement for businesses to make energy efficiency savings and armed with more data building owners and operators can make decisions that truly make a difference.
There is also the opportunity to get a complete picture of occupancy within the building and better plan and manage the space. There is the opportunity to analyse desks, departments, floors, and buildings over a set period of time to compare performance. Using the data can also ensure meeting rooms are used efficiently.
Light level and occupancy sensors are not just applicable for commercial and office and environments. They are also invaluable in industrial applications such as warehouses and car parks. These are often large spaces where certain areas are not used continuously, workers may not use all the aisles in the warehouse or particular levels in the car park might be empty. Although these spaces are not in constant operation, they do need lighting as soon as they are used, and this is where occupancy and light level sensors are important. There is no wasted energy if no one is in the space but at the same time the lighting comes on as soon as it is needed.
We need light for everything we do but that does not mean the lighting in our buildings needs to be on all the time. We need to be smarter about turning the lights on and off and, as the eyes and the ears of a building, sensors can play a vital role in ensuring the lighting is right all the time. As well as helping us gather important information about the operation of the building.