Good lighting promotes high quality learning. Paul Davidson takes a look at the issues requiring consideration when designing interior lighting schemes for educational establishments.

Gone are the days of the teacher standing in front of a blackboard where only one form of lighting was required to illuminate the space. Uniform lighting with focused brightness on the teaching wall may well have been the best solution then, but now – with the ever-growing use of electronic equipment and audio visual aids – the use of these traditional lighting schemes is proving to be woefully inadequate.

Instead, the main objective is to provide a lighting installation that offers a solution that encompasses audio-visual presentations and general teaching conditions. Such integrated lighting schemes are designed to illuminate the space in a way that addresses the actual tasks being undertaken rather than just providing the one solution fits suit all scenario. Through careful evaluation of the tasks being carried out, in respect of the conditions required for audio-visual presentation and general teaching, a solution that meets the clients’ specific requirements can be achieved.

A lighting scheme that distributes light from many different directions is considered to be more congenial than one where all the lighting is downward facing. Also, it is perceived that illuminating the walls and vertical surfaces will give the whole area a brighter and more welcoming feel.

Lighting uniformity and reflectance

Interior reflectances will have a major impact on the lighting of any space, which is why it is suggested that the colour scheme for these types of interiors is best served with light colours to make the space more visually comfortable. The added benefit of this is a possible reduction in luminaire numbers, or to use the same number of a smaller luminaire size, or a reduced lamp wattage.

Where general teaching takes place, there will be the need to offer a uniform lighting system, where illumination levels on the far surfaces of walls and ceiling are maintained by installing suspended luminaires that provide both direct and indirect illumination. Additional directional lighting can supplement the installation by directing light onto the main teaching board.

In the case of teaching spaces, where audio-visual presentations take place, the same installation is used, but with the removal of the indirect component of illumination and the directional lighting onto the main teaching board.

The best lighting solution can be achieved with the direct and indirect components working on different circuits. By specifying the luminaires with integral high frequency (HF) dimming control gear, the installation can provide an almost infinite number of solutions. The direct illumination will be controlled with non-specular satin aluminium louvres whilst the indirect component requires no such control.

Controlling glare and flicker

Glare is a factor in all environments as it can cause headaches and eyestrain, so it requires consideration when the lighting scheme is designed.

Direct glare is caused when students can see directly into the light source. Reflected glare occurs when the light is reflected back from surfaces within the space. Lamps can be shielded from view by using baffles, louvres, diffusers or perforated baskets in order to avoid direct glare. Glare from T5 lamps is greater than that generated by T8 lamps and these lamps should, therefore, only be used in luminaires that offer glare control. Larger numbers of smaller sized luminaires are considered to be more beneficial in reducing lamp glare.

Some people are very sensitive to the low frequency lamp flicker caused when using magnetic circuits. A solution to the problem is operating the fittings on HF ballasts with a frequency greater than 20kHz. For T5 lamps, HF ballasts are used as standard. HF offers the benefits of reduced sensitivity and flicker, instant starting, extended lamp life and reduced energy consumption, with savings of approximately 20-25% when compared with magnetic circuits.

It is also important to give consideration to lamp specification both in terms of its colour and colour rendering properties. Colour rendering describes the lamps ability to reveal true colour of the objects illuminated, whilst lamp colour describes the appearance in terms of warmth or coolness.

Use natural light too

Recent studies have shown that students have been found to learn significantly more in areas where there is more natural daylight, so most modern school buildings are being designed with this in mind. As classrooms usually have the windows along at least one side of the room, it is advisable to align the luminaires in rows running parallel to the windows.

This design concept will enable individual rows to be switched off when there is sufficient natural illumination. Alternatively, the use of lighting control systems, in conjunction with dimming control gear – which utilise daylight detectors that sense when the lighting levels are sufficient – is able to automatically control the amount of artificial lighting being provided by the luminaire. This provides a maintained lighting level and reduced energy consumption.

Such lighting control solutions can play an important role within the overall lighting scheme design as they not only control lighting levels and help to reduce energy consumption, but also provide the opportunity to vary the distribution of lighting between the direct and indirect sources. They also offer the flexibility to set illumination levels to match the tasks being performed, as well as being able to extinguish the lighting when the area is vacated. To make best use of natural daylight, the more sophisticated systems can dim the lighting closest to the windows to achieve a level lower than other luminaires, so maintaining an average illumination level across the entire space.

Energy saving frees up resources

Energy management and the ability to reduce energy consumption is a major consideration with all business mangers in the commercial world and schools and colleges are no different. As lighting can account for as much as 40% of the total cost of electricity used, it can place a huge burden on the school finances. To be able to reduce this 40% by 25% can lead to a total energy cost saving of around 10%, which can free up money for projects or the supply of additional equipment that will benefit the education and social development of students.

The reduction in energy consumption, combined with the improvement in interior lighting, not only reduces overhead costs, but will also – at the same time – provide students with a stimulating environment in which to learn. It therefore follows that the provision of good quality and energy efficient lighting schemes can make a significant difference to our environment, providing a more sustainable future for the next generation.