Interior Lighting Research Articles

Church Interior Lighting: A Semantic Differential Research

Lighting is essential for improving the visual conditions and meeting the needs of space users. It serves both quantitative and qualitative roles in a building. Furthermore, the lighting in a house of worship fulfills visual tasks and creates atmosphere for worship. This research aims to explore the perception of the Nazarene Christian Church (GKN) Filadelfia congregation regarding to the interior lighting conditions of their church using the semantic differential method. The results show that the congregation perceives the lighting is suitable for visual tasks, but the interior design falls short in creating the atmosphere required for a place of worship. This includes aspects like identity, warmth, intimacy, mystique, hierarchy, and expansiveness. The interior lighting of the Nazarene Christian Church Filadelfia needs to be redesigned to align with the church’s purpose and meaning, in addition to meet visual requirements.

Aircraft cabin lighting design method based on DIALux

Lighting in aircraft cabin is an important part of the aircraft interior lighting system. A reasonable cabin lighting design can improve the quality of flight services and enhance passenger satisfaction and comfort. In this paper, an aircraft cabin lighting design method is proposed based on the DIALux calculation and simulation software. Based on a quantitative evaluation, calibration and analysis of average illuminance, glare and uniformity of illuminance from the perspectives of travel safety, visual comfort and high quality service, the method explores and proposes an innovative approach to the design of aircraft cabin lighting. Finally, based on this method, an optical simulation model is established and visual simulation calculations are carried out to verify the feasibility of the method.

Natural lighting of interiors and sun protection of premises with roof lighting system

The article describes the contemporary issues of natural lighting of interiors of civil and industrial buildings. The major attention is given to the roof lighting system of the buildings in question, as far as this system provides not only increased levels of natural lighting, but sometimes an undesirable heat gains, due to prolonged insolation period and hence, extra solar radiation. It is noted, that this reason leads to design and construct the means of natural lighting in such a way, that to provide interiors with sufficient natural illumination and efficient sun protection at the same time. Some principal conclusions and recommendations were made as a result of analytic studies, presented in the article. For example, it was competently proved that the best solar standing solution for roof lighting installations are sheds, or sawtooth roof structure. The worst solution, to protect interiors from solar overheating are roof skylights. These skylights require extra sun protection in form of jalousies, blinds, etc. The same additional solar shading, though to less extend, is needed to provide additional sun protection for roof monitors.

Bidirectional optical response hydrogel with adjustable human comfort temperature for smart windows.

Smart windows are effective in reducing the energy consumption of air conditioning and lighting systems, while contributing to maintaining the comfort zone of temperature in the indoor environment. Currently used smart windows mainly rely on traditional single-phase thermochromic material in which only one abrupt optical change occurs during temperature changes, and their inherent characteristics may not be suited for a practical balance of energy saving and privacy protection. Here, we developed a novel bidirectional optically responsive smart window (BSW) with unique bidirectional optical response features by introducing sodium dodecyl sulfate (SDS)/potassium tartrate (PTH) micelles into PNIPAM hydrogel to form a composite hydrogel, which was encapsulated in two glass panels. The upper critical solution temperature (UCST) and lowest critical solution temperature (LCST) of the material can be individually adjusted and are capable of matching the human comfort zone of temperature. In addition, the smart window exhibits remarkable transparency (92.5%), visible light transmission ratio (Tlum = 91.31%), and excellent solar modulation (ΔTsol,UCST = 76.34%, ΔTsol,LCST = 76.75%). Moreover, it possesses selectivity in transmitting light in the infrared band of solar radiation and can complete the "transparent-opaque" transition in a very narrow temperature range (<1 °C). When at comfortable temperatures, the highly transparent smart windows facilitate interior light and appreciation of the view. At low temperatures, SDS/PTH micelles aggregate to form large micelles, blocking the transmission of light and protecting customer privacy. At high temperatures, PNIPAM can undergo a "sol-gel" transition, thus blocking incident solar radiation. Taken together, these proposed materials with bidirectional optical response characteristics would be harnessed as a promising platform for building energy conservation, anti-counterfeiting, information encryption, and temperature monitoring.

Exploring UV-222 Nano Meter Future Implications and Prospects in Electro Mobility

Abstract: The COVID-19 pandemic has brought attention to the necessity of an adequate disinfection system to fight dangerous and contagious diseases. Current cleaning procedures are frequently laborious and time-consuming. Researchers are investigating the use of cutting-edge technologies to safeguard the worldwide populace against the spread of viruses and other illnesses to address this issue. A UV-222 nm light-based disinfection system has been suggested as a possible remedy in this regard to counteract the impacts of viruses and maintain a clean and secure environment. The implementation of UV-222 nm light-based disinfection systems and their prospective influence on healthcare technology are the main topics of this article. The technology can address issues with the spread of viruses and bacteria in a variety of contexts, including car headlights, public lighting, interior lights in homes, and other sterilising techniques. Additionally, the high-way geometry of UVC sterilisation has been theoretically formulated and investigated. Healthcare professionals, medical physicists, biomedical and clinical engineers, and other associated groups are the target audience for this article. In order to enhance patient safety, disease surveillance, and management, the study discusses the potential advantages of UV-222 nm light-based disinfection systems. We also talk about the ethical, moral, and legal ramifications of using such technology. In conclusion, this research offers a fresh viewpoint on UV-222 nm light-based disinfection systems and their prospective influence on medical technology. In order to improve patient care and safety, we hope that this conversation will promote additional research and development in the area of healthcare technology

Design optimization of office building envelope by developed farmland fertility algorithm for energy saving

This study focuses on designing sustainable buildings with a specific emphasis on reducing energy consumption and optimizing costs. To address the time-consuming nature of simulation software like TRNSYS and Energy Plus, a novel meta-heuristic optimization algorithm called the Developed Optimization Algorithm of Farmland Fertility (DFFA) is provided. The DFFA algorithm is utilized to optimize parameters related to the building envelope, encompassing walls, windows, and glass curtain walls, aiming to minimize energy demand and construction expenses. Comparative analysis with other approaches such as EPO, LOA, MVO, and FFA demonstrates significant reductions in energy consumption and building design costs achieved by employing the proposed algorithm. Furthermore, the DFFA algorithm yields the desired results within fewer iterations. By increasing the surface area of the glass curtain wall and total window space, improvements in natural ventilation and interior lighting are observed. Despite similar window opening measurements across the compared methods, the suggested algorithm surpasses others when it comes to overall cost and energy efficiency. The total cost reduction compared to the initial design amounts to 39 %. Thus, the DFFA algorithm proves to be more effective in conserving energy in buildings compared to other analyzed procedures. This research serves as a case study and presents a promising method applicable to designing various building types under different weather conditions in future projects.

The New Office Space of Interior Lighting Design Research Form

With the advent of the new era, the epidemic has had a profound impact on both work and life. The new form of office space should not only complete the work through lighting design, but also create a more healthy, comfortable, warm and humanized environment. This paper, through the thinking of unlimited office space, starts from the mobile, interleaved and interruptible space, and uses the design to create unlimited office from the overall style, space atmosphere and functionality of different lighting ways, etc. The new form of office space is reflected and improved due to the lighting design.

The impact of facade geometry on visual comfort and energy consumption in an office building in different climates

In recent years, there has been a heightened emphasis improving visual comfort and energy efficiency. Various solutions have been explored to achieve high-performance design. Shading devices play a crucial role in enhancing building performance by redusing solar gains, excessive daylight, and improving both energy efficiency and occupants' visual comfort. This research aims to investigate the effect of facade geometry on visual comfort and energy consumption in four different climates of Iran and categorize each variable based on effectiveness for each location. Parametric office modeling was done by using Grasshopper and Rhino software. Then, the effect of the facade on the interior lighting and energy consumption was analyzed by Radiance, Daysim, and EnergyPlus calculation engines. The Non-Dominated Sorting Genetic Algorithm (NSGA-II) was selected to optimize solutions, minimize energy consumption, maximize useful daylight illuminance, and view quality. In addition, the methodology was used to explore the framework for optimizing office facade design in Iran's diverse climatic zones. The simulation results indicate that window-to-wall ratio and inclined wall were essential for balancing daylighting performance and energy consumption. This research stated that using a self-shading design could increase the quality of view up to 75% while reducing energy consumption and the risk of glare. Results proposed a design framework to improve visual comfort and save energy. The rotating façade's wall 10°-30° reduced cooling energy demand and energy usage intensity in selected models. So, an inclined wall could be an efficient shading device to improve building's performance in Iran.

ОСВІТЛЕННЯ У КВАРТИРАХ ПРИСТОСОВАНИХ ДЛЯ ГАРМОНІЙНОГО СПІВІСНУВАННЯ ЛЮДЕЙ ТА ТВАРИН

Interior lighting in pet-friendly apartments is a multifaceted and important aspect of creating a harmonious living environment for both humans and their companions. Research will include the importance of lighting in pet-friendly interiors, delving into design features, technologies and benefits that promote the well-being of both pets and their owners. Research sheds light on the art and science of pet-focused lighting, from providing comfort and safety to improving overall quality of life. We begin by recognizing the deep connection between people and their pets. Lighting in pet-friendly apartments serves not only practical purposes, but also helps create an environment that nurtures this unique bond. Natural lighting is a cornerstone of pet-friendly interiors. We investigate the benefits of using sufficient natural light, including its positive effects on animal behavior, circadian rhythms and general well-being. Different pets have different lighting needs. Whether it's providing adequate UVB light for reptiles or creating cozy nooks for feline sunbathing, we explore lighting settings for different animal species. Lighting is adapted to specific areas of pet activity, such as feeding, play and rest areas. We discuss how task lighting and LED lights adapt to different tasks and activities related to pets. Lighting is key to keeping pets safe. We examine how the right lighting can prevent accidents, such as tripping over pets in low-light conditions. We investigate the effects of lighting color on both pets and their owners. The psychology of color is studied, it is emphasized how lighting can affect mood and behavior. Intelligent lighting systems are increasingly being integrated into pet-friendly apartments. Consider the convenience of remote control, scheduling, and motion-activated lighting for pets and owners. Lighting is an integral part of the overall well-being and health of pets. We discuss how natural light conditions and well-planned artificial lighting can positively affect the physical and emotional health of animals. It is important to take care of the safety of pets and lighting. We outline measures to protect pets from electrical hazards and prevent damage to lighting fixtures caused by curious animals. The Future of Pet Lighting: We conclude with a look at the future of pet-centric lighting, including innovations in smart pet monitoring systems and advanced lighting technologies that will further enrich the lives of pets and their owners. In summary, this abstract highlights the key role of lighting in pet-friendly apartment interiors. By taking into account the special needs of pets, taking advantage of natural light and implementing smart lighting solutions, we can create living spaces that prioritize the well-being, safety and happiness of both the occupants and their beloved companion animals.

Techno-economic analysis to determine the potential of perovskite-based PV blinds for buildings

This paper analyses a novel perovskite-based Photovoltaic (PV) blind system for buildings. Some buildings are unable to install traditional solar systems because they cannot install PV panels on the roof or facade. Traditional PV materials have a long value chain, also the resulting solar panels are bulky and heavy and not suitable for blind applications. Recently, Perovskite crystals, a new semiconductor material, have shown potential for reducing the manufacturing cost while providing high energy conversion efficiency. However, a significant issue with PV blind systems is that they typically receive less solar radiation than traditional rooftop PV systems, resulting in less electricity generation, particularly when the PV blinds are used indoors behind the windows. In addition, unlike conventional rooftop PV panels, PV blind systems affect the total energy consumption in the building by changing the heating and cooling demands as well as interior lighting. Utilizing these new PV blind systems effectively necessitates a holistic analysis of solar potential, performance, and cost-effectiveness. In this study, whole-building energy simulation, techno-economical modeling, and parametric analysis will be used to compare perovskites PV blinds and conventional rooftop PV arrays.

A Study of the Emotional Impact of Interior Lighting Color in Rural Bed and Breakfast Space Design

In architectural spaces, the ambiance created by lighting plays a significant role in influencing people’s emotions, often relying on the use of color and light. However, previous research has primarily focused on urban architectural spaces, with relatively less attention given to rural environments, especially the interior spaces of rural accommodation. The objective of this study is to investigate the impact of colored lighting within rural accommodation interiors on people’s emotions and visual perceptions. Additionally, the study aims to establish an emotional dimension model to map the experimental results onto eight basic emotions, utilizing the PAD model for quantitative analysis. To achieve this goal, the researchers recruited 90 participants and divided them into six groups, each experiencing different combinations of indoor lighting scenes with varying colors. Participants evaluated their emotions and visual perceptions. The study results indicate that the combination of cool and warm white light with colored light significantly influences the arousal level of participants but has a relatively lower impact on pleasure levels, dominance and relaxation levels. In comparing the emotions experienced after exposure to cool and warm white light followed by colored light, warm white light elicited more positive emotions. Furthermore, colored light following cool white light diminished the sense of warmth in light, while yellow–blue light enhanced visual comfort and blue–red light increased attraction. Overall, the effect of colored lighting in rural accommodation interior spaces on improving negative emotions was relatively weak. Conversely, the combination of warm white light with blue–yellow or green–yellow light had a more significant effect on enhancing visual perceptions and reducing participants’ anxiety. This research provides valuable insights and references for designing the lighting ambiance in rural accommodation interiors and lighting design, with the potential to enhance the spatial experience of rural accommodations.

The simplified equipment selection method for the cove lighting

Cove lighting has become a widespread way of interior lighting due to the current popularization of linear LED strips. It is a type of indirect lighting usually used as interior decoration. However, it is possible to use this lighting type to meet general lighting requirements. The work presents the theoretical description of the cove lighting effects and the results of computer simulation and experimental tests on the mock-up model. The accuracy of computer simulation of cove lighting is sufficiently high. Because of that, it was possible to carry out further simulation tests. The results determined how the individual components of the geometry of the illuminated room (height, surface area, and the location of cove lighting equipment) affect the obtained level of average illuminance and its uniformity. The main result of the work is the determination of a simplified procedure for selecting cove lighting equipment. Thus, it is possible to quickly determine the value of the luminous flux of the LED strips so that a proper level of average illuminance (with relatively high uniformity) in the interior with a known height and surface area is achieved. The proposed procedure may significantly facilitate the design of cove lighting for architects and engineers.

Ticari Bir Şişe Soğutucu Üzerine Bir İnceleme: Farklı Malzeme ve Şekillere Sahip Yükleme Paketlerinin Enerji Tüketimi ve Performans Üzerindeki Etkisi

Commercial coolers are designed specifically for commercial use in various industries, such as food service, hospitality, and retail. They come in different shapes, sizes, and configurations, with varying features and capabilities depending on the intended use. The most common types are beverage coolers, wine cabinets, ice cream cabinets, glass-front coolers. The cooling system is an important factor to consider when purchasing a commercial cooler, with forced air-cooling being the most common type. Energy consumption can vary depending on size, type, and usage, with many models now designed to be energy-efficient. Other important factors to consider include capacity, noise level, and specific features such as adjustable temperature control, energy efficiency, self-closing doors, safety locks, and interior lighting. The study included an IPD test which determine the time it takes for a commercial cooler designed for cooling beverages to reach the desired temperature from the ambient temperature at the desired range for Aluminum Cans and PET bottles, as well as measuring the energy consumption of a fully stabilized commercial bottle cooler.

Physico-mechanical properties and shielding efficiency in relation to mineralogical and geochemical compositions of Um Had granitoid, Central Eastern Desert, Egypt

The current work aims to describe the physico-mechanical characteristics and shielding efficiency with reference to the mineralogical and geochemical compositions of the Neoproterozoic Um Had composite granitoid pluton in order to deduce their favorability as dimension stones. The Um Had granitoid pluton has an elliptical outline with a mean diameter of about 10 km. This pluton is a composite (ranging from white to reddish pink color), hard, massive, and medium- to coarse-grained granitoid body. It is classified as syenogranite according to their modal and bulk chemical compositions. Geochemically, the granitoid pluton is a highly calc-alkaline, peraluminous granite, formed by low degree partial melting of tonalitic source rock in a post-collisional tectonic setting. The physico-mechanical properties of the granitoid pluton under study satisfy the requirements of dimension stone in terms of their bulk density (from 2561 to 2564 kg/m3), and to some extent water absorption capacity (from 0.38% to 0.55%). However, their compressive strength values (50.4–113.4 MPa) do not achieve the minimum requirement for interior use and light duty exterior use. This study delves into the potential of some of our syenogranite samples (I, IIA, IIS, and 10) as gamma radiation shielding materials. We have assessed the mass attenuation coefficient (GMAC), effective atomic number (Zeff), exposure build-up factor (EBF), and energy absorption build-up factor (EABF) for each of these samples. The GMAC and Zeff calculations were performed using the Phy-X online software, across a photon energy range of 0.015–15 MeV. Our findings suggest an inverse relationship between photon energy and GMAC, with the highest values observed for the (I) granite sample (∼18). This study shows the promising radiation shielding capacity of our samples. The insights derived from GMAC, Zeff, EBF, and EABF can serve as a guide for the development of effective, naturally sourced radiation shielding materials.

The Effect of Illuminance Artificial Light Interior on Color Difference Identification in People with Colour Vision Deficiency (CVD)

Individuals with color vision deficiency (CVD) face challenges in various daily activities that require color identification such as selecting appropriate clothing combinations, identifying ripe fruits or vegetables, et cetera. This study aims to identify the best illuminance artificial lighting for color difference identification among individuals with CVD in Indonesia (0,7%). The research focuses on the quantitative analysis of experimental data to assess the effect of different types of illuminance artificial lighting on color perception in participant with CVD. A controlled experiment was conducted with a sample of individuals diagnosed with CVD (Deutronomali, Deutronopia, and Protonopia), utilizing a standardized color difference identification test based on Natural Color system (NCS) as the color experiment tools. The participant was exposed to different artificial lighting conditions, including various intensities (illuminance) and different color background (black or white) for each category. Quantitative data is collected, focusing on the accuracy, speed, and total steps for completing the task under different artificial illuminance conditions. Statistical analysis, including analyses of variance (ANOVA) and correlation analyses, are conducted to examine the relationship between illuminance lightings and color difference identification in individual with CVD. The results based on the analysis of duration, number of steps, and accuracy, the optimal illuminance level for identification color differences falls within the range 400-500 lux. The second-best illuminance level falls within the range 300-400 lux. In conclusion, range 300-500 lux are the best illuminance level for perceiving color variation.

A Distributed Intelligent Lighting Control System Based on Deep Reinforcement Learning

With the rapid development of human society, people’s requirements for lighting are also increasing. The amount of energy consumed by lighting systems in buildings is increasing, but most current lighting systems are inefficient and provide insufficient light comfort. Therefore, this paper proposes an intelligent lighting control system based on a distributed architecture, incorporating a dynamic shading system for adjusting the interior lighting environment. The system comprises two subsystems: lighting and shading. The shading subsystem utilizes fuzzy control logic to control lighting based on the room’s temperature and illumination, thereby achieving rapid control with fewer calculations. The lighting subsystem employs a Deep Deterministic Policy Gradient (DDPG) algorithm to optimize the luminaire dimming problem based on room illuminance in order to maximize user convenience while achieving uniform illumination. This paper also includes the construction of a prototype box on which the system is evaluated in two distinct circumstances. The results of the tests demonstrate that the system functions properly, has stability and real-time performance, and can adapt to complex and variable outdoor environments. The maximum relative error between actual and expected illuminance is less than 10%, and the average relative error is less than 5% when achieving uniform illuminance.

Sky-like interior light settings: a preference study

This paper explores human observer preferences for various sky-like interior lighting scenarios realized by a combination of a blue-enriched indirect uplight 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 downlight component. Variations in the natural sky were mimicked by the indirect uplight 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 component and 6,500, 7,500, 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 component and a cooler, blue-enriched CCT in the indirect lighting component leads to a maximum in the subjects’ preference ratings. In summary, the subjects preferred light settings with a white appearance on the work surface without any intense or noticeable blue cast or tint.

Treatment of Potted Zebra Plant and Inch Plant with Antigibberellin Plant Growth Regulators Slows Stem Elongation in an Interior Green Wall

In commercial interior green walls, plant trimming and replacement necessitated by stem elongation under low interior light levels is labor intensive and costly. Antigibberellin plant growth regulators (PGRs) may slow stem elongation and thus reduce maintenance costs in this environment. In Expt. 1, two PGRs were applied as foliar spray or drench to three spiderwort selections [two of zebra plant (Tradescantia zebrina) and one of inch plant (Tradescantia fluminensis)] immediately before installation in a green wall, each at three rates: ancymidol (ANC) foliar spray at 25, 100, and 200 mg·L−1; paclobutrazol (PBZ) foliar spray at 20, 80, and 160 mg·L−1; and PBZ drench at 1, 4, and 8 mg·L−1, along with an untreated control. In Expt. 2, 80 mg·L−1 PBZ foliar spray, 1 mg·L−1 PBZ applied via subirrigation four times, and the combination of these two treatments, was evaluated on ‘Burgundy’ zebra plant. In both experiments, plants were placed in a vertical modular tray interior green wall. Change in total stem and specific internode length were measured every 14 days after installation for 3 months to calculate growth per month. Antigibberellin application slowed internode elongation of spiderwort selections during the first month after installation. Antigibberellins were more effective in zebra plant at reducing overall stem growth rate and less so on inch plant. Across the three spiderwort selections, 25 mg·L−1 foliar spray of ANC resulted in no difference in growth rate when compared with the control, although 100 to 200 mg·L−1 foliar spray was effective. Based on the results of both experiments, moderate and high rates of PBZ, applied both as a foliar spray and drench, resulted in similar reduction in stem elongation. PBZ applied as 20 to 80 mg·L−1 foliar spray, 4 mg·L−1 drench before installation in the wall, or a combination of an 80 mg·L−1 PBZ pre-installation foliar spray and recurring 1 mg·L−1 via subirrigation (four times) were effective at growth suppression of spiderworts for at least 3 months. Even rates of PBZ of 160 mg·L−1 foliar spray or 8 mg·L−1 drench did not show phytotoxicity in treated plants and could be considered for use. We recommend a pre-installation application of 80 mg·L−1 foliar spray or 4 mg·L−1 drench for controlling stem growth across spiderwort selections. Application of antigibberellin PGRs to plants before installation in green walls slows stem growth and can contribute to reduced maintenance costs.

Hierarchically porous carbonized Pleurotus eryngii based solar steam generator for efficient wastewater purification

Solar steam generation has been considered as an effective strategy to alleviate freshwater shortage. Interfacial solar steam generation utilizing biomass materials as the core of evaporator has shown great potential to overcome the freshwater crisis based on its distinctive natural structure. Herein, we reported a sustainable, efficient and convenient biomass solar evaporator using carbonized Pleurotus eryngii (C-PE). Benefiting from the microporous carbon skeleton and microchannels cooperatively work, the as-prepared device exhibited the integrated functions of excellent photothermal conversion and rapid evaporation. The hierarchically porous structure of C-PE could entice interior multiple light reflection to enable all-directional light absorption (>92.1%) and enhance the capability of photothermal conversion. This device showed a high evaporation rate of 1.22 kg m−2 h−1 under a power density of 1 kW m−2. Moreover, the high efficiencies of 81.7% under 1 kW m−2 power density and 95.1% under 4 kW m−2 power density for C-PE evaporator were achieved. Furthermore, C-PE was used to extract potable condensate from wastewater samples containing Na+, heavy metal ions, dyes, and oil. With the advantages of low-cost, abundant and long-term stability, C-PE evaporator showed great application potential in clean water production, which can be used for future bio-derived solar thermal material.

Τhe effect of artificial lighting on both biophilic and human-centric design

The indoor environmental quality is very significant as humans spend more than 90% in indoor space. Biophilic design of indoor spaces has become a popular approach in the design of indoor building spaces sector using green walls, especially in offices, leisure and hospitality facilities. So far there exist neither guidelines with the proper Spectral Power Distribution (SPD) except for agricultural applications or intensity levels of lighting nor the proper spectral indices to transform the photopic illuminance to a new type of photometric quantity for biophilic design. On the other hand, for human centric lighting the Equivalent Melatonin Illuminance is already introduced. The aim of paper is to define the appropriate lighting conditions, not only for humans, but also for interior plants. A new metric was introduced for the biophilic design named Equivalent Photosynthetic Illuminance. The new metric was examined for two human-centric lighting luminaires and compared with the corresponding human centric lighting metrics in order to create a lighting design guide for energy-sustainable, biophilic and human-centered lighting. The different SPDs highlighted the counterbalancing impact(s) of such luminaires, between biophilic and human-centered design. The differences concerning their impact on interior lighting design were identified with regards to energy consumption, meaning that the compliance of the lighting conditions to both humans and plants results to higher energy consumption. Depending on the SPD and luminous efficacy of artificial lighting, the additional power density for proper planning of biophilic design can vary from 23.5W/m2 to 52.4W/m2 in the areas in which are applied.