I had an interesting meeting this week where the focus was once again squarely on Energy saving and not so much on the technology. Now you might ask why was this so interesting?
Since the LEDification of our lighting, im not sure if that’s a real word but you get the point, the focus has moved away from energy as it was always assumed that the bulk of the energy saving was delivered by the change in light source. A reduction in operating power relates to a saving in energy and for the most part this is true. However, there are a number of caveats and these relate to a number of issues.
The first is perhaps not surprising in that not all LED lighting is efficient and that a low cost solution with a low cost driver will be inefficient and will consume more power than claimed. Also as the driver ages the efficiency of that driver will also suffer.
Replacement luminaires may not meet the requirements of the original design intent and simply replacing an efficiency T5 fluorescent luminaire with a flat panel LED may not illuminate the space as intended. With schemes based around some upward component the selection of the replacement light source must be carefully considered. The data provided by some of these retrofit solutions talk about high lumen efficiencies but its meaningless unless that energy is converted into usable light. Beware the snake oil salesman who claims this is equivalent to product X for example, ask for the data to support this.
The most efficient luminaire is one that is switched off so simply managing the space through the use of a PIR or similar will turn off the lighting when its not needed or in the ideal world be dimmed to provide feedback on a change of status and also improve the user experience and security for late workers. Simply switching is too clunky and destroys the look and feel of the lit space and this is why so called intelligent luminaires can fail if they just focus on the space below them. Intelligence design ensures notional corridors are maintained and the look and feel of the space is maintained albeit at a reduced output to save energy.
There is a massive energy saving when updating our lighting to LED and this is a once in a 20 year period or similar dividend that we can all bank, but with a little work these savings can be further increased by the use a of few simple tricks
All buildings would benefit from continuous commissioning as the scheme design was often based on a blanket value across an open plan office or space without any furniture or partitions. Replacing the existing light source with another, although more efficient won’t address the fact that certain areas are over-lit and therefore you are wasting energy. Light the task and reduce the lighting in background areas to reflect the true lighting conditions and where possible use daylight to supplement artificial lighting. With smart sensing technology change the way in which sensors operate based on the time of day and also the seasonal changes.
Review the building regularly to ensure its operating at peak efficiency and design the building to accept future upgrades to add more control and enhanced analytics.
Illuminate the areas you need to at the appropriate level, don’t waste light!
Measure the energy usage and use this data along with occupancy patterns to make decisions that may impact on switching periods and if the system is as smart as zencontrol, adjust the periods throughout the day to suit various working patterns.
Daylight is free, it’s good for our wellbeing and it changes the whole dynamic of a space so utilise daylight and balance the natural with the artificial. In a similar manner we should use blinds to alleviate glare and reduce solar gain in fully glazed facades and if they are intelligent blinds then direct daylight onto the ceiling to throw daylight further into the building.
Don’t automatically turn on the lighting, it’s a habit that many of us get into but if there is enough light and we are working on a computer screen do we need any additional illumination. Absence control where we monitor an individual leaving a space but don’t sense them arriving is by far the most efficient way to provide a basic level of control.
Design your controls to be flexible and smart so you can very simply reconfigure. Typically, App based solutions now provide the building owner, user or their engineers the opportunity to modify the parameters of a building using an App connected to the system. Where available Cloud based systems using a mix of analytics and some Artificial intelligence can learn patterns of occupancy and can in certain instances detect individuals and provide a bespoke lighting solution.
Tailoring lighting to suit our needs and providing a degree of control empowers the individual and, in most instances, result in lower lighting levels. We all work on positive contrast screens and therefore our focus is more on the screen and no so much the desk, so different parameters apply.
Obviously public spaces or retail have different requirements and a uniform illumination would be preferable and if there is a specific lit affect you are trying to create then individual control may not be practical.
Saving energy is still a key benefit of lighting control and although we focus more on the added value of controls, we should not forget that correctly managed we save energy, reduce the carbon footprint of that space and if properly designed provide a framework for future development and saving.
Lighting control is going through somewhat of a renaissance at the moment with discussions around topics such as the Internet of Things etc being a prime focus of what controls can achieve but we must never forget that for every smart building there is a building that requires just the basic level of control.
Education is the key to delivering energy savings and this can be from simply explaining how much energy we use on lighting and heating so that we switch off or turn down the lighting/ heating or we use the appropriate technology to suit the application. A PIR switching a luminaire works, it works better when dimmed but it’s still turning lighting off when it’s not required.
Picking up on a point I mentioned earlier, scalability of controls is crucial to achieve a long-term energy plan to reduce consumption and optimise your building. Get the basics right from the offset and further savings can be achieved through continuous commissioning or through the addition of new smarter technology through the life of the building.
Consult an expert and seek advice on the appropriate solution for you and above all remember that a well thought out controls solutions not only saves energy but saves money in the long term.
Stewart Langdown FSLL