Artificial lighting can have a key impact on biological efficiency, experts say
Over the course of evolution, humans have developed a circadian system which anticipates changes in the world around us and coordinates the 24-hour cycle in all our bodily functions. In 2002, scientists discovered ganglion cells in the retina of our eyes that are not used for seeing but instead respond to the blue content in daylight. This in turn sets our body’s master clock and synchronises our internal system with the external cycle of day and night.
This effectively means that certain kinds of light can alter our body functioning by either increasing our alertness and performance or making us feel relaxed and drowsy, and it is this ability to control the way people perform that the lighting industry is tapping into.
Shedding some light on the matter, lighting solutions specialist Kevin Thompson, product and marketing director for Middle East, India and Africa at Zumtobel Lighting GmbH, says the purpose of biologically effective artificial lighting is to enhance the impact of daylight indoors.
“The Zumtobel group is investing a lot of time and effort to help customers understand the benefits of this in fields such as healthcare, office, education and retail. What we’re doing is looking at the best solutions to bring daylight indoors.
“From our perspective, understanding the customer’s application is a key part of creating the correct solution, and lighting for non-visual effects is no different. The starting point is understanding how people interact with the space or environment in which we are trying to find the best solution, and how this technology allows us to improve the activity carried out in that space.
“The non-visual effects of lighting is a fast-growing field, so in order to manage this activity, we work closely with different customer groups and with independent research labs and education authorities. We then use the expertise in our R&D teams to create the best possible solution. It is key that as a lighting industry we get as much scientific evidence of the potential benefits as possible, in order to help our customers make an informed decision on whether the technology is suitable or not.”
The intensity, spectrum, timing and exposure pattern of light is key to the impact of artificial lighting on biological efficiency. Jerferson Baltrami, senior lighting design architect at Studio Lite Middle East, explains, “All these factors are influential. The intensity of light is the most important, and research shows that the secretion of melatonin [a hormone that regulates sleep and wake cycles] can be suppressed in a healthy human being in spaces with an illuminance of 1600 to 3200 lux, and is not affected if the illuminance level is under 200 lux.”
Paul Miles, principal lighting designer and partner at LightTouch LPD, agrees, saying, “Historically, we have focused on enhanced light levels leading to high amounts of energy usage to illuminate internal spaces. This met the minimal lux level criteria set by international standards and lighting guides relating only to the visual spectrum, where we believed it would provide increased efficiency. This potential has a negative impact on our circadian rhythm.”
“With this new research, it has been quite apparent that the requirement is not purely down to light intensity on a dedicated surface, but the clever use of light as well, like illuminating numerous surfaces rather than a single plane. Lighting control systems play an important role and are fundamental in lighting design. No longer should this technology be deemed as a luxury, but more of a necessity to enhance the value and impact of interior lighting.”
The non-visual effect of light has a number of applications and installations in sectors such as commercial, hospitality, retail, medical institutions and public spaces. Baltrami notes, “Lighting design has to be proposed in a way that is focused on the activities to be performed in the different scenarios and the behaviour expected by the users. If the activity to be performed requires attention and energy, then a high illuminance level in a neutral or cool white colour has to be proposed. If the intention is to keep the user relaxed, then a low illuminance level in warm or neutral white colour temperature is needed.”
In an office, for example, Miles explains that lighting plays an even more important role, since employees are in a static position for long periods of the day with minimal daylight ingress and thus tend to get tired and less productive. “By animating the lighting in a space through the use of changes in light intensity and colour temperature that reflect daylight conditions, we can help stimulate the brain to make a person more productive.”
“In fact, studies have shown that a better-lit environment also helps reduce the number of sick days taken by employees. For multinational organisations where the number of staff is in the thousands, an investment in the right lighting design can considerably increase productivity, resulting in efficiency, which of course leads to high commercial value.”
Similar applications can be made at retail stores and malls as well, explains Miles. “The non-visual spectrum can be manipulated in a different way in retail. The key aspect of retail is to increase sales, and this is generally through impulse buying. By increasing the intensity of light at a specific point of sale, we as humans will be subconsciously drawn to the display and this will increase the chance of making an impulse buy.”
“Another key aspect to retail is way guidance. You want your customers during their visit to a shop or mall to be carried past as many products as possible to increase the possibility again of an impulse buy. The clever use of light intensity can guide the shopper through a particular route to maximise this potential.”
In bars and restaurants, lighting depends on the route to market of the retailer, be it a commodity sales target in a fast food chain or providing a signature experience in a restaurant. Miles explains, “In an environment that is well-lit, there is a potential that people would naturally walk faster and not spend long periods of time within. Therefore, for fast food restaurants where high levels of footfall is key to increase the number of sales, this is certainly the approach to go.”
In hospitals, the effects of the non-visual spectrum have been studied in depth by medical experts, who have found that daylight is key to the recovery of a patient and is even more important in ICU units where people are coming around after intense surgery.
Though using the non-visual spectrum definitely has its economic and commercial benefits, the challenge may be that it is not entirely understood. Faraz Izhar, senior lighting designer at KEO’s Design Division, says he definitely considers it a good value add for specific and particular lighting applications, if not all.
“The extent of application is quite relative. As a designer, you may be thinking about it at some level for each and every project. In fact, the projects for which I’ve thought about applying the non-visual effects of lighting solutions, right from the concept, are our educational projects, and particularly some schools that we have recently finished.
“Subconsciously, most lighting designers in the Middle East may already be applying it to their projects in principle. For example, if a designer is doing something as simple as using daylight white colour temperature luminaires within an office, he or she is already applying it to an extent.
“Applications are catching up fast in the European and North American sectors, where there is even a Human Centric Lighting Society. In the Middle East, though, I would say that while lighting designers are already aware, people – particularly the end clients – in general here are still in the process of understanding it. Having said that, I think the region will soon catch up, within the next three or four years.”
In terms of the cost, Thompson says, “It’s difficult to give an exact answer, but if you’re comparing conventional technology versus the implementation of LED technology and advance controls and daylight management, then we can easily achieve cost saving on energy of up to 60-70%.”
Izhar says it depends on the extent to which you want to apply it, and how tight your purse strings are. “If the budget permits and if the client asks for it, the designer can go up a few notches and think on a much larger level. This could mean the optimum integration of artificial lighting and daylight, or the use of cooler light colour temperature during the day and warmer light colour temperature during the evenings.”
“It could also be the usage of tuneable white light fixtures, or appropriate lighting controls for individual rooms. Minimum things considered, it could cost you maybe at least 25% over and above your regular lighting design costs.”
The effects of the non-visual spectrum, and the level to which it dictates our performance at the work place, restaurant or at home, are undeniable. As for the frequency of its conscious application, Thompson adds, “I think the Middle East is slightly behind on implementation, as it was for LED, but as more studies are carried out and people talk about the benefits, I don’t see why it won’t improve. One point to consider is that this part of the world doesn’t have such a clearly defined seasonal change where daylight becomes a problem in winter months. However, there are still many environments where natural light is a problem.”
Izhar agrees, saying the Middle East is yet to understand its full potential. “The requests are very selective for this kind of solution in the region and mainly come from the healthcare and education sector.”