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Human perception and vision have evolved in response to dynamic daylight, a combination of radiation from direct sunlight and diffuse skylight, which has created a flow of variations in light, in terms of direct:diffuse distribution, intensities and spectrum. This study investigates the qualities of the flow of light in an office after adding ceili...
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... participants were asked to choose which tasks they would imagine carrying out under the different light settings. The differences between the settings with direct lighting and with no direct lighting were analyzed; see Fig. 5. We employed spider plots to visually compare the light settings. The most notable increase was in socializing, which tended increase as the ratio increased. On the other hand, writing and reading tasks displayed clear decreases as the ratio increased. The additional directional lighting tended to cover more tasks, although further ...
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... in addition to the other four activities (writing, reading, computer work and meetings). Indicators showed that uneven lighting distribution creating light-zones best facilitated socializing, although further study on this is needed. Moreover, the data show a tendency for increased directional lighting supports a large spread of tasks; see Fig. ...
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Citations
... (Tung, An and Anh, 2023;Yu et al., 2021;Yan et al., 2020). As of today, the fluorescent as well as incandescent outdated lights can be altered in favour of white-light-emitting diodes (WLEDs) because this light source generation offers various qualities including significant performance, low energy consumption, greater durability, etc (Henry and Guruviah, 2020;Kumar et al., 2020;Hansen et al., 2022). These devices are often created by incorporating yellow YAG:Ce 3+ phosphors and blue InGaN chips. ...
... Similarly, another study indicated that for office workplaces, the field of view and the viewing angle are important for the brightness reaching the eye . Hansen et al. (2022) conducted two experiments with direct spotlights and diffuse indirect light. The first experiment found that 55%-85% indirect light is preferred over different tasks and avoids discomfort due to glare. ...
... To collect the participants' subjective preference ratings associated with various sky-like light settings during the experiments, a dedicated questionnaire was used for the assessment, as shown in Figure 3. Regarding its first four questions, a semantic differential with a bipolar seven-point intensity rating scale with words provided for each step between antonyms was adopted from Tifler and Rea (1992), Ploder and Eder (2015), and Hansen et al. (2022), who used this type of scale-identified as suitable for this purpose by Flynn et al. (1979)-to measure subjective impressions in similar lighting contexts. For the fifth question, on the other hand, which collects an overall rating of general appeal for the current lighting situation, a FIGURE 2 Spectra of the two direct (down: 2,700, 6,500 K) and the seven indirect LED channels (up: blue, cyan, orange, lime, red, white 2,700 K, and white 6,500 K) which can be individually controlled. ...
... The value was chosen with consideration of the standardized horizontal illuminance of 500 lx (DIN EN 12464-1) and the preference for higher illuminance of 850 lx up to 2,000 lx. Furthermore, in order to ensure comparability to other literature works (Fleischer et al., 2001;Keis et al., 2014;Hansen et al., 2022), the value is not chosen higher. The measured values of irradiance and corresponding illuminance at the eye level are displayed in Table 3 for the direct part and Table 4 for the indirect component. ...
This paper explores human observer preferences for various sky-like interior lighting scenarios realized by a combination of a blue-enriched indirect up-light component with a correlated color temperature (CCT) of 6,500 K up to 30,000 K and a 4,000 K or 5,500 K direct down-light component. Variations of the natural sky were mimicked by the indirect up-light component reflected from the ceiling of the experimental room. The settings for the direct lighting component, on the other hand, were selected based on the reported outcomes of previous preference studies in the field of interior lighting. The resulting lighting conditions were evaluated by a total of 29 observers, from which subjective ratings of brightness, sky-likeness, satisfaction, pleasantness, and general appeal were collected in an office workplace environment. In this experimental setting, the most preferred lighting conditions exhibited a direct to indirect lighting ratio of 50:50 with a CCT of 4,000 K in the direct and of 6,500 K, 7,500 K, and 9,000 K in the indirect component. For all examined combinations, none was rated as truly sky-like. Nonetheless, the study results showed that only the combination of a warmer CCT in the direct and a cooler, blue-enriched CCT in the indirect lighting component leads to a maximum in the subjects' preference ratings.
... However, due to the COVID-19 pandemic, as the line between homes and offices blurred, some companies that have a human centered work culture begun to seek ways to transform their office spaces via new learnings of this era. We would IOP Publishing doi: 10.1088/1755-1315/1099/1/012029 2 like to illustrate this trend with a few examples. Research and design lab Space10 renewed their office space to adapt to the "new normal" by creating an office space that is tailored around its users' needs, providing more flexibility, fluidity, and variety [4]. ...
... The qualitative side of the user research has been supported by two semi-structured interviews, one with a user of the space (in person interview), the other with the Business Area Manager of the company that is responsible of the administration of the building where the office in case is located (phone interview). Second, researchers' [8][9][10] and those that fit the current project (described under section 4.1. Design Criteria), have been transferred. ...
... For diffuse materials, reflectance (ρ) was estimated using a Testo 540 Luxmeter. Illuminance has been measured 15 cm distance from the material's surface, first toward the surface (reflected light) and after away from it (surface incoming light) as done in previous DDL studies [10] For non-diffuse materials, such as glossy and specular, this method cannot be used and due to the lack of access to measuring device such as a gloss meter, a visual method has been used to classify the reflectance type of these materials. From different angles, photos of the materials have been made and the presence of a directional distribution of light has been assessed. ...
Often the criteria for designing office lighting is to increase efficiency through a bright and evenly distributed lighting. Yet, research has found that this static lighting leads to an unstimulating, boring, and dull luminous environment that supports neither task focus, nor a pleasant atmosphere. The goal of this paper is to create a closer connection to a natural light environment by designing an office lighting that inspired by light as natural phenomenon creates a lively and more nature-based atmosphere. We developed a lighting design with focus on analysing the perceived atmosphere as a metric for a dynamic lighting design for a meeting room of a real estate company in Denmark. Through a mixed method approach, we explore the design factors that determine the desired natural atmosphere. Our design aims at enhancing the function of the meeting room as a formal space where negotiations are held by 1) presenting the identity of the company to the business partners; and 2) supporting employees’ sense of belonging to the company culture. As a result, our lighting design creates a lighting hierarchy in line with the architectural elements of the space, complementing daylight through electric lighting in a dynamic way, accounting for both sky-type and daylight inflow.
... It has been established that the dynamic feature of daylight is highly appreciated [ 7 , 20 ], hence the replication of its features on interior environments seems to have positive effects on the occupants. As shown in [21] , a combination of cooler general lighting and warm direct lighting in clear sky conditions was found preferable by the study subjects, while neutral light for general, and warmer for direct lighting was preferred on overcast conditions. Providing an adjustable CCT feature on task lighting is favored by the users [22] , signifying positive effects on alertness, visual comfort, performance [23] , as well as on the circadian stimulus [24] . ...
A control strategy targeting energy and comfort goals, is implemented in an individual and an open-space office, to control blinds and dimming lighting as part of an MPC intelligent control system. The study aims to achieve occupant's com- fort and an improved energy use in a quasi-real time optimization of the interior environment, using discomfort glare and work plane illuminance as KPIs. By the inclusion of task lighting, the user's preferences in regards to the interior lighting environment (CCT and lighting intensity), are considered. Those are assessed by a longitudinal user experiment, along with its benefits for the electric lighting energy reduction. Aiming to more responsive predictions, daylight and electric lighting surrogate models (LightGBM) were developed for each room based on year-round RADIANCE simulations. Implemented on a 32-bit computer (Raspberry-Pi 3B), the intelligent control system would promptly adjust blinds and dimming lighting through a KNX system, based on the model's prediction of the KPIs. The results showed that the system manages to provide a comfortable interior environment for the occupants, while energy reductions of at least 49% could be achieved compared with a conventional building operation. While a rather uncommitted acceptance of the system was reported by the occupants, improvements can be achieved by allowing a higher level of control that could be customized according to personality traits.
... In the term run, employers do not plan to change their office layouts significantly. However, this statement contradicts with other studies [17,62,63] that have indicated the need for adjustments. It can be argued that the possibility of remote work results in the lack of, or insufficient reorganization of, office space. ...
The pandemic is fast-moving, accelerating rapid changes that lead to new challenges and impacting organizations. A big mark has been left on the workplaces—places where we do business—because the ongoing change to remote work challenges the role of the office. It is highly possible that as the change progresses, the workplace will not only change its design but also the way in which work will be planned, organized, performed and controlled. However, as the restrictions ease up, questions arise: What is the potential of office sustainability? How has the perception of flexible office space changed due to the COVID-19 pandemic? This paper used an online survey as a quantitative research method. In this paper, we looked at the employer’s vision of the office. We investigated employers’ perspectives of where and in what settings the work will be performed in the post-pandemic time. Specifically, we discussed the changes employers will apply in terms of the work environment and office layout. The findings suggest that an increasing mobile workforce and expansion of the new work style will not mean an office exodus but will certainly have an impact on office utilization.
... In the term run, employers do not plan to change their office layouts significantly. However, this statement contradicts with other studies [17,62,63] that have indicated the need for adjustments. It can be argued that the possibility of remote work results in the lack of, or insufficient reorganization of, office space. ...
The pandemic is fast moving, accelerating rapid changes that lead to new challenges and making organizations suffer an impact. A big mark has been left on the workplaces-places where we do business, because an ongoing change to remote work challenges the role of the office. It is highly possible that as the change is progressing, it is not only the workplace that will change its design, but also the way in which work will be planned, organized, done and controlled. However, as the restrictions ease up questions appear: What is the potential of office sustainability? How has the perception of flexible office space changed due to the COVID-19 pandemic? This paper used an online survey as a quantitative research method. In this paper, we looked at the employer's vision of the office. We investigated employers' perspectives of where and in what settings the work will be done in the post-pandemic time. Specifically, we discussed the changes employers will apply in terms of work environment and office layout. The findings suggest that an increasing mobile workforce and expansion of the new workstyle will not mean an office exodus, but will certainly have an impact on office utilization.
... Research projects, such as the Double Dynamic Lighting research (DDL), have already been studying the spatial distribution of light through lighting hierarchies and combined CCT, inspired by the natural dynamics of daylight changes between cool skylight and warm direct sunlight. Through layers of electrical light, combining diffuse cold and direct warm electrical light, the DDL project studied how the spatial distribution of light becomes more balanced through a combination of different lighting qualities that respond to the dynamic changes of the daylight intake [16,38]. ...
... The discussion argues for a more holistic approach to the daylight performance indicators-visual needs, physiological needs and energy aspects, where a common evaluation framework throughout the design process, will result in a more nuanced interpretation of daylight's diverse qualities. Understanding daylight as a diverse source to both visually pleasant light through a focus on flow, directionality and hierarchies of light (the DDL approach) [16,38], provides a guideline for the supplement of electrical lighting (DDL and CIE's Integrative Lighting) [3,16,37,38] and as a way for optimizing indoor climate and energy efficiency, through a more optimal intake of daylight. Further the focus on both visual and physiological effects through two different measuring methods, can be seen as an opportunity to rethink how we quantify light in accordance with actual needs, by focusing on light that reaches the eyes for both visual and physiological needs. ...
... The discussion argues for a more holistic approach to the daylight performance indicators-visual needs, physiological needs and energy aspects, where a common evaluation framework throughout the design process, will result in a more nuanced interpretation of daylight's diverse qualities. Understanding daylight as a diverse source to both visually pleasant light through a focus on flow, directionality and hierarchies of light (the DDL approach) [16,38], provides a guideline for the supplement of electrical lighting (DDL and CIE's Integrative Lighting) [3,16,37,38] and as a way for optimizing indoor climate and energy efficiency, through a more optimal intake of daylight. Further the focus on both visual and physiological effects through two different measuring methods, can be seen as an opportunity to rethink how we quantify light in accordance with actual needs, by focusing on light that reaches the eyes for both visual and physiological needs. ...
A holistic approach to daylight dynamics in our built environment can have beneficial outcomes for both physiological and visual effects on humans. Simulations of how daylight variables affect light levels on the horizontal work plane are compared to their physiological effects, measured as melanopic EDI (Melanopic Equivalent Daylight Illuminance) on a vertical plane. The melanopic EDI levels were calculated in a simulated office space in ALFA software (Adaptive Lighting for Alertness) employing the daylight variables of orientation, time of day, season, sky conditions and spatial orientation. Results were analyzed for how daylight design can contribute to the physiological effects of dynamic light in office buildings. Daylight is shown to be a sufficient light source in the majority of cases to meet the recommended values of EDI and provide the suggested horizontal lx level according to the Danish Standards. A mapping of daylight conditions, focusing on the specific factors presented here, can provide guidelines in the design process and future smart building systems. The complex interrelationship between these parameters is important to acknowledge when working with daylight dynamics as a sustainable element in architecture and lighting design.
... The tentative results indicate that dynamic lighting has a positive effect on visual comfort, perceived atmosphere, and work engagement compared to static lighting (74). Another study (75) from the same author investigated the quality of light in an office after adding ceiling-mounted spotlights to traditional diffuse ceiling panels with the intention to complement the directionality of the natural daylight inflow from windows. The visual light quality and perceived atmosphere of the office environment was tested with 30 volunteers through questionnaires, reaction cards and semi-structured interviews. ...
Nowadays lighting projects often include temporal variations of the light, both spectrally and in terms of intensity to consider non-visual effects of light on people. However, as of today there are no specific regulations. Compliance with common lighting standards that address visual aspects of light, often means that only little non-visually effective light reaches the eye. In this practice review we confront existing regulations and standards on visual lighting aspects with new recommendations on non-visual aspects and highlight conflicts among them. We conclude with lighting recommendations that address both aspects.
... This understanding of the perceived spatial character of dynamic daylight as a flow of light, referring to the ratio of direct sunlight and diffuse skylight to their respective CCTs (correlated colour temperatures), was used as a reference for the double dynamic lighting concept developed for this experiment. 31 The novelty in this proposed design concept is that the daylight and electrical lighting are integrated as one lighting component, by letting the variation of diffuse/ direct ratio and the CCT of dynamic electrical lighting complement the dynamics in the sky and daylight level. This integrated lighting concept creates light zones in the workplace through directional electrical light sources. ...
... A full description of the pilot tests can be found in the designated paper. 31 The outcome of the two pilot studies suggested the following design criteria for the experimental study: ...
The experiment was targeted to develop design strategies and methods by testing the complex interplay between the dynamics of daylight and electrical lighting in an office. The double dynamic lighting design concept is based on the idea of adding task lighting, with a directionality referring to the daylight inflow and a variation on direct/diffuse lighting and respective changes in colour temperature respond to sky conditions and daylight levels. The experiment was conducted in an office space at Aalborg University in Copenhagen from September to December 2019. Four participants moved in and worked in the office with four-week periods of respective standard static lighting as a baseline, and dynamic lighting. In a parallel mixed method approach with interviews and questionnaires, the dynamic lighting was compared to the baseline and to a control group. The results indicate that the dynamic lighting periods had a positive effect on visual comfort, perceived atmosphere and work engagement. The studies helped to develop the definition of five dynamic light settings. Seasonal changes, time of day, dynamic sunscreens and individual needs for task lighting can be implemented in future field experiments as additional dynamic parameters to meet individual needs and circadian potentials for double dynamic light.
