Integration of energy-efficient lighting and acoustic elements for better spatial experience, well-being and learning in schools

The incentive to develop new lighting solutions in the Danish primary and lower secondary schools has become more urgent after with the introduction of the new Danish school reform, which requires more flexibility in the schools' physical framework. The new Danish school reform towards a holistic school with a more diverse set of activities places demands on learning spaces, both in terms of acoustics and light. In relation to the potential for energy savings in lighting systems, it is inevitable to have to look for alternatives to light sources that are being phased out. When changing lighting systems, it is obvious to assess the ceiling solution as a whole and optimize both visual design, acoustics and lighting.

The purpose of the project has been to develop new ceiling solutions that - by simple lighting control and improved lighting in combination with acoustic elements - can reduce energy consumption and at the same time increase the space experience and thereby increase learning and well-being in school. The project therefore wanted to promote a holistic solution thinking in the area of indoor climate optimization with a focus on combining light and acoustics.

The design solution that was a prerequisite for the study consists of a flexible acoustic element with an associated LED lighting fixture, which with its light distribution creates a) direct light for optimal working conditions and b) orientational light reflected from the acoustic elements. The overall effect is, in addition to the fact that the new combi-solution, now complies with the current requirements for both child and adult education, while the entire ceiling surface is now also visually illuminated, which makes the room feel brighter. The wavy structure, repeated on both the front and back of all acoustic elements, helps to highlight the structure of the light by a faded shadow pattern on the illuminated surfaces of the panels. The wave pattern also gives a difference in the density of the acoustic material, which tries to optimize the acoustic environment, regardless of the placement of students and teachers in the classroom.

The project has ended in a physical full-scale experimental setup and tests have been performed in two comparable classrooms at Skovbrynet School in Gladsaxe municipality and a digital twin in VR of the premises with similar acoustics and visual expression. VR simulations and VR tests with trial participants were performed in a test room at BUILD (Aalborg University, Copenhagen).

The results from VR tests show that the design solution is generally preferred over the outdated ceiling solution, but which parameter (acoustic or visual) has the greatest significance for the overall preference is difficult to assess from the data. However, there tends to be a difference in both acoustic and visual preference at the two locations subjects were placed at during the experiment (far from the instructor, close to the instructor). In addition, in the VR test, there is a general tendency for an acoustic preference for the design solution over the acoustics in the reference room, and that the visual environment tends to influence the assessment of the acoustic environment.

In terms of estimated electricity consumption of the new solution, this was not far from the outdated reference solution, but the lighting levels of the non-renovated room were far from the standard requirements for light in classrooms (reference Em = 184lx - design solution Em = 475lx). A saving by comparison under the same illuminance could reduce energy consumption by ca. 47% without daylight control and approx. 63% with daylight control.

The project has functioned as a pilot project focusing on a multisensory holistic experience. It often happens that in the world of research, the senses are isolated to avoid sources of error, but does this make the results more reliable compared to real scenarios? The project has therefore paved the way for a new strategy with a more holistic approach. We foresee that in more projects in the future, there will be a greater focus on the “not measurable” and multisensory aspects, as it is rarely only quantitative values that describe the world as we experience it.

This newly developed method can in future projects, make it easier to assess and rank several digital environments / twins with associated sound and image, up against each other and up against their energy consumption. In this way, large and costly full-scale experiments and mockup experiments are avoided, and therefore the risk of insufficient and / or energy-intensive lighting systems in the future is minimized.

We therefore see that the project has both contributed useful knowledge in its design solution, but also in the prepared test method. Which in the future gives rise to new interpretations of more flexible, functional, and aesthetic ceiling systems as well as deeper studies of the developed test method in the future.