Nowadays, up to 80% of information is processed visually. Besides the fact that light influences personal well-being and health, it also has a positive impact on motivation and performance. What has to be taken in to consideration when it comes to lighting in the workplace?
Light has different functions that have to be taken into consideration for comprehensive assessment of a lighting concept in a room. Illumination does not only support the visual perception and therefore the information brokerage, but it is also signified by psychic-emotional and psychic-biological effects.
The visual perception in a room is initially achieved by illumination. Therefore, ceiling fixtures have to be chosen individually according to the room condition. In addition, table lights and floor lamps can intensify the lighting effect. They are also able to zoom in on information processing and mental stimulation at the same time.
The appropriate use of daylight and artificial light can have a strong impact on the psychic-emotional factors of lighting. Other factors that are influenced by light are health and performance. An ergonomically designed lighting can be very supporting and as studies have proofed, a good illumination at the working place has also an impact on motivation.
For the evaluation of quality of illumination, a variety of parameters is analysed. The major criteria are lighting level and illuminance, harmonic brightness control, light colour, direction of light and restriction of glare and shadiness. Those parameters, influencing visual environment, comfort and performance, are frequently noted in scientific and practical approaches.
Recommendations for the lighting in the workplace
The following light-measures are suggested to optimise lighting at the workplace:
(1) Just as any other lighting concept, lighting at the working place should be flexible and energy-saving. An optimal lighting depends on the visual task and requires both a balance of indirect and direct light sources, as well as a balance between daylight and artificial light.
(2) Flexible application, energy saving and ergonomics are requirements that have to be met by modern lighting technologies. A combination of different types of lamps enables an individual illumination in rooms according to the visual tasks. Additionally, manufacturers provide energy-efficient LED bulbs.
(3) One of the most important criterions for lighting at the work place is the respective work- and visual task. This decides on the choice of illuminants.
Lighting level and illuminance
A minimum of 500 Lux is stated for the brightness at computer work stations. Generally speaking, an increase in illuminance boosts the visual performance and positively influences the detailed and fast visual information processing. An illuminance between 500 and 1000 Lux can also be seen as stress-free.
The more complex the visual task is, the higher the illuminance requested. Additionally, person variables like the age are crucial for a final and overall evaluation of the chosen lighting concept. An illuminance between 750 and 1 000 Lux is said to sustainably enhance the working performance of elder workers.
Mood lighting is often achieved by the illumination parameter light colour. In this regard a rendering index (CRI) is used as orientation. Indices from 90 Ra can be seen as natural values and are used for example in connection with LED lights and fluorescent lamps. For a further characterisation of illuminants and light sources, the light colour of fluorescent lamps is compared to the light colour and illuminance of light bulbs. This leads to the following classification of light colours: warm white, neutral white and bright white.
Also, effects of light and shadows decide on the lighting quality. To achieve a balance between natural and artificial light and to avoid shadows and glare, it is recommendable to place lights parallel to the window and the working place. This coherence was already pointed out by one of the first studies of the Ergonomic Institute (1997). If the visual comfort is directly compromised by light sources with a very high illuminance in the visual field, lighting experts refer to glare as a parameter of illumination. Reflection is the second phenomenon that negatively influences the lighting quality.
Daylight and artificial light
The combination of different light sources contributes to a lighting concept that can be adapted to the different light requirements. The use of direct and indirect lighting in addition to a balanced day- and artificial light, is very important. On the one hand, in offices and at computer work stations a very high level of indirect lighting is recommended to support non-glaring. On the other hand, direct lighting provides the essential shadiness for a good illumination. That is the reason why combining both illumination techniques is vital.
Also, it is necessary to use appropriate bulbs for right illumination (general lighting), as they support the task lighting in the room. Lights with a movable luminaire head are highly recommended for a suitable lighting at the workplace. When both computer-assisted and other tasks have to be managed from one workplace, individually placed table lamps serve as additional light sources. At some work places dimmable lights can also be advantageous.
Source: www.lightingdeluxe.com
Discussing office illumination with OPPLE Lighting
Rakesh Vassanjee and Johan Geldenhuys from OPPLE Lighting spoke to Lighting in Design about the latest trends in office lighting.
LiD: From your perspective, what are the current trends you are noticing?
OPPLE: Currently in the market, the focus is on getting proper lighting into the office, for instance, the correct temperature. Designers are looking at the number of hours one sits at the desk or by a computer, and the subsequent trend is to install the correct lighting and the correct size of fitting for that lighting. We have designed two panels that can be fitted into either a suspended ceiling or mounted onto a concrete celling in variations of 6 x 12 and 6 x 6 panels, available in colour temperatures of daylight and cool light. They are also flicker-free which is important in an office environment and reduces triggering epilepsy and migraines.
LiD: Is human centric lighting being driven from clients or the suppliers?
OPPLE: It is coming from both. With our extensive R&D department, OPPLE is continuously developing new ideas, hence our ranges of anti-glare, flicker-free and non-reflective lights. Cool white, 4000 K is becoming the preferred choice for an office environment these days as people need to be comfortable due to the hours spent at work.
LiD: Are the requirements in South Africa different to the overseas markets?
OPPLE: In Europe the requirements are very high, and locally we need to meet the SABS standards. There are so many LEDs that have flooded the market at the moment. Overseas, people don’t mind spending the extra money on lighting, yet in our market people are more price conscious. Because there are so many players in the market, people have been burnt with other brands and been let down before, which is detrimental to the genuine suppliers.
LiD: When will we get to the same stage as Europe in terms of smart lighting?
OPPLE: When our economy allows clients to spend that money! We are getting some requests for it currently, but are finding that locally we don’t have the infrastructure in place to manage the modern light sources.
LiD: What is the ideal future for lighting in office environments?
OPPLE: Lights that are efficient and easily installed, as well as a focus on the correct colour temperatures in an office. Many engineers are starting to come to us to spec the product because they are now realising the need to do a lux reading, for example. The amount of desks and how much natural light comes into the building all play a role, and that’s where we have the advantage because we have done those case studies.
LiD: Do you find that architects have a good understanding of lighting?
OPPLE: Many still need to be brought up to speed – we call on many architects, designers and lighting engineers, to educate them on what is available and what they can actually use in their projects. A lot of people are still set in their ways with what they have always used – we want to educate so the right products can be specified. A lot of the architects are surprised by the technologies available – they are becoming smaller, more compact and more user friendly, which impacts on their design.
Architects need to sit down with the brands and find out what is available in the market. A lot of the engineers are also set in their ways; they work purely within the budget and don’t look at the long term. A lot of custom made lighting is great, but when those lights fail, how do you repair and replace it quickly? As such, we like to futureproof our designs, so that as technologies change, you will still be able to use the same cut out, for instance, so that without having to replace the whole ceiling, you can still maintain or upgrade the fitting in the future.
