Cost saving, convenience and comfort: the case for lighting control systems
From Legrand Australia.
Building owners and developers understand the importance of energy efficient solutions. While many incentive schemes are in place to reward green performance, the bottom line is that reductions in energy usage equate directly with lower operating costs.
Consequently, where once the capital cost of a building or renovation project was the primary concern, today developers take a more holistic view that includes a building’s long-term performance. In effect, it is a balancing act: the additional costs of including energy-saving technologies weighed against the operational savings that those technologies can deliver throughout the life of the building.
Interestingly, just a few short years ago, energy-saving technologies were expensive and offered limited scope to recover costs, with payback periods commonly measured in decades. However, the increasing efficacy and lower costs associated with today’s latest green solutions mean their inclusion in a development often adds an almost insignificant amount to the overall budget, while their ability to reduce energy usage has conversely increased dramatically.
For example, installing cutting-edge lighting control technologies in a commercial building can deliver up to 55% of lighting energy consumption. This means payback periods are frequently less than five years, and in some instances can even be measured in months.
The latest lighting control solutions typically fall into two categories: standalone switch sensors and networked systems that use communication protocols such as BUS/SCS, DALI or KNX. These systems both use lighting management technologies that include Passive Infra Red (PIR), Dual Technology and Microwave sensors.
PIR detects heat from occupants and provides up to 45m2 of coverage per sensor. Dual Technology combines ultrasonic capabilities—which detects sound waves that bounce off occupants—and PIR within the same unit, and these can cover an area up to 90m2 per sensor. Microwave sensors detect motion and have much greater coverage and sensitivity. However, as they are also able to detect movement through glass, care often needs to be taken with regard to Microwave sensor positioning in many applications.
This choice of sensors means that lighting control solutions can be tailored to the specific needs of each project. Of equal importance are the lighting management strategies employed—the way the system is programmed to use the sensor information—as this dictates how the lighting system operates. Commonly used strategies include ‘occupancy-based control’, ‘vacancy-based control’, ‘daylighting’, ‘scheduled control’, ‘dimming control’, or a combination of these.
Occupancy-based control activates lighting in an area as soon as it is occupied, while vacancy-based control conversely turns off lights when an area has been vacant for a set period. These systems can be programmed to deliver site-specific effects, such as illuminating an entire pathway to an exit, for example, in order to anticipate the users’ needs and optimise their experience.
Daylighting works by measuring natural light levels and dimming lighting up or down in order to maintain design levels of illumination across an area. This solution is most valuable for larger open-plan spaces where natural light is present. At the brightest part of the day, lighting can be dimmed down or even switched off, and is usually set up to activate in separate zones parallel to the windows. Daylighting solutions can be as high-tech as the user wants, with more zones and more dimming increments programmed into the system to achieve finer levels of control.
Scheduled control allows lights to be turned on/off or dimmed up/down at specific times. While this is arguably not a very flexible arrangement in itself, it can be useful for businesses with very predicable operating hours or alternatively in conjunction with other lighting management strategies. Likewise, dimming control offers a fairly basic way to adjust light levels up or down for an area but when used in conjunction with daylighting, scheduled control, vacancy – or occupancy – based control, it can offer extremely sophisticated and responsive outcomes.
Of course, the energy/cost savings are not the only reason why lighting control solutions are becoming increasingly popular in the workplace. These systems deliver unprecedented levels of user convenience and comfort, and even provide that ‘wow’ factor to impress building occupants and visitors. Moreover, many studies have shown the benefits to employees of having lighting tailored to specific tasks as it makes the work easier and more enjoyable. Good lighting has even been proven to increase employee productivity, their health and sense of wellbeing, and reduce absenteeism.
With lighting control solutions reducing costs, improving environmental performance, and optimising employee comfort and convenience, the question is not how you can justify specifying a lighting control solution for your workplace but rather to ask yourself why you have not taken the step before now.