Lighting Energy Performance Research Articles

A proposal on residential lighting design considering visual requirements, circadian factors and energy performance of lighting

ABSTRACT This study assesses residential areas which have been converted into workplaces and are still used after the Covid-19 in terms of visual, non-visual, and energy performance requirements of lighting. We proposed a lighting design using LED systems with dimmable and tuneable features. Circadian factors in WELL Building Standard are analyzed for compatibility with the current visual requirements. The impact of various design parameters on lighting energy consumption, including daylight availability, lighting schedules, lighting control strategies, and light reflectance value of walls is evaluated through a case study in Turkey. Although the annual lighting energy consumption is higher than it was before the pandemic, building energy simulation results show that the application of LED systems with lighting energy measures can improve lighting energy performance by up to 38%. From the non-visual dimension of light, our data indicate that higher melanopic illuminance and/or colour temperature of light sources are necessary to entrain and sustain the circadian rhythm under overcast sky conditions in winter months. On the other hand, an increase in luminous intensity can lead to glare and higher energy consumption while a higher colour temperature may affect the physiology and psychology of occupants negatively.

Evaluation of the Lighting Energy Performance of Educational Buildings with BEP-TR Methodology: The Case of ERU Faculty of Architecture

As part of energy efficiency and conservation measures, central and local governments have developed various action plans, international commitments, calculation models, regulations, standards, and certificates and arrangements. Building Energy Performance (BEP-TR), a national calculation method developed according to the conditions of Turkey, is one of them. With BEP-TR, the energy efficiency of the building is measured in existing or alternative situations. In public buildings, the issue of energy efficiency is vital in terms of being an example. In the framework of this study, the Faculty of Architecture of Erciyes University as an educational and public structure was selected as the study area. Lighting is essential in electricity consumption in public buildings, especially educational establishments. This study aims to guide the energy efficiency principles and lighting design on the axis of comfort-cost and consumption for all public buildings, especially educational buildings, by emphasizing that the concept of energy efficiency should be handled multi-dimensionally with its various layers. Current state data to measure using the BEP-TR will be assessed if the lighting is energy efficient, according to visual comfort needs. Lighting energy consumption values were recalculated by checking the alternatives, simulations, and visual comfort criteria developed concerning energy efficiency. With the revision of the lighting design, the amount of savings to be realized by the system that meets the requirements for visual comfort was calculated. While the improvements proposed in the study were handled under the title of the artificial lighting system, other parameters were kept constant. In improvements alternatives, while offering a physical and psychological enhancement for users, it also saves energy in public buildings and bring an ecological proposition to reduce the carbon footprint for nature. Considering the proposal in the context of comfort-consumption-cost and amortization. The calculation of how long the initial investment cost will be amortized with the amount of savings has been made using three different methods. The study shows originality in responding to the designer’s aesthetic concerns with the multi-dimensional inputs of energy efficiency.

Optimal tunnel lighting design in aspect of lighting quality and energy performance

The lighting quality and energy performance of tunnel lighting systems based on different tunnel lighting designs are investigated to identify the optimal tunnel lighting design. Furthermore, the lighting qualities of various mounting heights and luminaire spacing are discussed based on different tunnel lighting parameters. Thereafter, the luminaire spacing is optimized for various road widths and luminaire power. Finally, the effects of the surface reflectance of the wall, ceiling, and road are compared in terms of the lighting quality and energy performance. The results indicate that the mounting patterns have a significant effect on the average luminance in the single-row arrangement. A symmetrical system with ceiling mounting can provide remarkable overall and longitudinal uniformities. Reducing the mounting height from 7 m to 5.5 m results in greater average luminance and better TI of about 11 % and 45 % respectively, but the overall and longitudinal uniformities are degraded by 20 % − 30 % and 30 % − 45 % respectively. In addition, reducing the distance between the luminaires from 30 m to 10 m improves the total tunnel lighting quality, i.e., 67 % of average luminance, 55 % of overall uniformity, 75 % of longitudinal uniformity, and 60 % of TI. In addition, the road, wall, and ceiling surface reflectance have a dominant effect on the lighting quality. A tunnel surface with low reflectance degrades the lighting quality, resulting in minimum luminaire spacing and poor energy efficiency.

What public lighting governance model should be deployed in Moroccan cities for sustainable and efficient energy management?

The strategy of public lighting in Morocco is today a real urban issue: a well-lit city satisfies citizens and is a factor of development, attractiveness, safety and economy for communities. Urban authorities are challenged to define the right lighting, where it is needed, when it is needed, how it is needed and at the best cost. In the midst of economic and industrial growth and in the face of societal challenges, Morocco is aiming to achieve ambitious energy independence targets while meeting its commitments to sustainable development. To this end, Morocco has developed an energy efficiency strategy, one of the main axes of which is the implementation of efficient public lighting services by 2030 with the ambition of reducing electricity consumption by 13%. Public lighting in Morocco represents a significant burden for municipalities. There are more than 1.5 million light points in urban municipalities, for an estimated annual consumption of 1,000 GWh, with an annual increase of 8%. The related investment and operating expenses reached about 3.5 billion DH in 2018. The objective of this paper is to present an analysis of the governance of public lighting in Morocco. It presents the various obstacles and constraints to achieving effective management of public lighting. The first step consists of an analysis of the modes of governance of public lighting in Moroccan cities. Then, a proposal for a public lighting governance mechanism is made on the basis of an international benchmark, including proposals for improving the energy performance of public lighting.

기후대별 솔라사이니지 반투명 태양전지 창호 적용 사무용 건물의 에너지 성능분석

Purpose: This study analyzed building heating, cooling, and lighting energy performance and power generation performance under various climate zones in accordance with Solar Signage Semi-transparent window application. Method: American climate areas, them being tropical, desert, maritime, and microthermal, have been selected and 40%~80% window wall ratio (WWR) has been established in relation to five Solar Signage Semi-transparent windows. Designbuilder, building energy analyzation software, was used to model office building and simulate. Result: Total energy consumption presented Phoenix was highest, followed by Miami, Ann Arbor, with San Francisco being the lowest. The smaller the WWR the higher the heating energy consumption at San Francisco and Ann Arbor appeared with G1 window confirmed to be the highest. Cooling energy consumption in all four climate zones increased as WWR increased due to increase in amount of solar gain. Lighting energy consumption in all four climate zones decreased as WWR increased, with G5 showing smaller consumption than G1 due to VLT’s influence. Climate zone with the amount of energy savings on account of power generation being largest turned out to be San Francisco. Especially, possibility of zero energy building achievement in case of G1, G2 window being applied when WWR was 80% was confirmed. With the result of this particular research, to expand applicability as building exterior materials, products improved upon traits such as colour, insulation, and strength should be under continuous performance evaluation study across various foreign and domestic climate zones.

Optimized lighting energy consumption for non-visual effects: A case study in office spaces based on field test and simulation

Recently, the non-visual effects of the light environment have received increasing attention. Some standards have proposed evaluation metrics for non-visual effects in office spaces to ensure the health and well-being of occupants. Non-visual metrics are new requirements for indoor light environments, whose impacts on lighting adjustment and ultimate lighting energy performance are currently unknown. Therefore, this study aimed to present a workflow to obtain optimal light outputs considering non-visual lighting requirements, in addition to traditional visual requirements. This workflow was implemented to calculate the annual lighting energy consumption under different light correlated color temperatures (CCTs), daylight conditions, and standard requirements for an actual office scenario. As deduced from the results, adding non-visual requirements may significantly increase the lighting energy consumption by 57 %. Furthermore, daylight and light with a higher CCT are beneficial for non-visual energy-saving. The additional non-visual requirements will not increase the lighting energy consumption under favorable daylight conditions. The 5500 K light can save up to 20 % of the annual lighting power consumption than the 4000 K light. The presented workflow and conclusions contribute to engineering office environments with enhanced lighting, better circadian stimulus, and improved office lighting energy efficiency.

Typical Values of Energy Performance Indicators in Road Lighting

Amongst many road lighting design criteria, energy performance plays an important role as it has a~direct link to operational costs, potential reduction of carbon dioxide emissions, mitigation of obtrusive light, and its impact on the night-time environment in urban and conurban settlements. The energy performance of road lighting is conveniently described by the pair of normative numerical indicators PDI and AECI established in European standards. This article aims to present typical values of these indicators for different combinations of road arrangements, road widths, lighting classes and light source technologies to illustrate what benchmarks can be expected using this assessment system. Objectives of the article also comprise discussion on factors influencing the energy performance and conclusion whether it is appropriate to introduce limiting value requirements and/or ranking systems to label energy performance of road lighting systems.

AN INVESTIGATION BY THE BEP-TR METHOD OF THE EFFECT OF OBSTRUCTION ANGLE PARAMETER ON LIGHTING ENERGY PERFORMANCE AND DAYLIGHT SUPPLY

ABSTRACT Following the EN 15193, 2008 Energy Performance in Buildings Regulation in the European Union Member States, a comprehensive calculation can be made on lighting energy performance and daylight effect. This improved model accounts for Turkey’s “BEP-TR” (“Regulation on Energy Performance in Buildings”). In the present study, the effect of the obstruction angle parameter of buildings on lighting energy consumption and daylight provided is examined through a sample hotel project by the BEP-TR calculation method. This study investigates the effect of daylight on lighting energy performance alternatives that were produced according to the height, building distance variations (causing obstruction angle), and the correlation between annual lighting consumption values, daylight supply factor, and obstruction parameters. Accordingly, the current study aims to develop a method to assist zoning regulations, building intervals, and height decisions by determining specific ratios between obstruction parameters, daylight supply factor and lighting energy consumption values. Results of this study clearly show that obstruction parameter variables affect both the daylight supply factor and annual lighting energy significantly.

Lighting energy performance determination in office environments through implementation of EN 15193-1 for Turkey

Office buildings are building typologies where efficient and optimal use of lighting energy is crucial while providing comfortable visual environments. The purpose of this study is to explore the impact of diverse architectural design alternatives on lighting energy requirements and lighting energy saving possibilities through a case study. In this study, a total of 3888 design alternatives are investigated in a comparative way in terms of daylighting system design alternatives, artificial lighting system design scenarios, artificial lighting system control types and shading system control options. Introducing the adaptation process of the EN 15193-1:2017 standard for Turkey’s specific climatic and geographical conditions and considering diverse lighting design scenarios, results of this parametric study aim to underline the significance of architectural design strategies in office buildings for the reduction of lighting energy requirements.

Assessment of control strategy of adaptive façades for heating, cooling, lighting energy conservation and glare prevention

A movable shading device installed on an adaptive façade is able to change the positions of the shades according to the various control objectives (i.e. daylighting, thermal comfort, glare, energy, etc.) of the occupant. Since the key variables and the control method may change according to the control objectives, it is important to determine the hourly states of the shades in consideration of all of these factors. This study proposes a multi-purposes control strategy of adaptive facades for heating, cooling, lighting energy and glare. To depict the movements of the movable shading devices, the operable range is represented by an n number of fixed shade states having constant intervals. The control strategy entails deriving allowable shade states for glare prevention and energy conservation independently and then deriving the intersection range between the two shade state ranges. A case study was performed to verify the changes in hourly shade states and the energy performance of the envelope obtained by applying the proposed control strategy to an adaptive façade having a movable folding type shading device. The results of the case study show that hourly shade states were determined to satisfy the objectives of glare prevention and energy conservation simultaneously based on weather conditions and indoor requirement settings. From the case study, it can be seen that the proposed method can block the entry of direct solar radiation by lowering the unshaded fraction according to whether or not there would be discomfort glare while increasing the view factor in certain sections to promote the entry of diffuse solar radiation into the indoor space during the cooling and heating periods. The results of the case study also show that there can be large differences in the heating, cooling, and lighting energy performance of the building envelope for each orientation depending on the order of priority given to the objectives of the shading control, i.e. the objective of energy conservation only and the objective of simultaneous glare prevention and energy conservation. However, it was possible to effectively reduce the differences in energy proportions by adopting translucent shades.

사무소 건물 적용 PCW 창호의 기후대별 에너지 성능 분석

Purpose: This study analyzed building cooling, heating and lighting energy performance of the photochromic window (PCW) in various climate zones. Method: Office buildings were modeled using DesignBuilder software, which is a building energy analysis program, and four climate regions-Temperate climate, Tropical climate, Marine climate, and Cold climate were selected to test the performance of PCW. Result: Due to the characteristics of U-value and shading coefficient (SC) of PCW, indoor heat loss decreased in winter resulting in a decrease in heating energy consumption. On the other hand, cooling energy consumption decreased due to less transmission solar radiation in summer. As for the lighting energy consumption, the PCW

사무소 건물 적용 DSSC BIPV 창호의 환경 및 에너지성능 분석

Purpose: This study aimed at analyzing the building indoor environment conditions and energy performance when DSSC BIPV windows are applied, and building a database to suggest the appropriate performance level of DSSC BIPV windows in future buildings. Method: The DesignBuilder, a building energy analysis program, was used to evaluate indoor illuminance, room temperature, cooling and heating energy, lighting energy, and power generation performance. Result: Simulation results demonstrate that the current characteristics of DSSC BIPVs exhibit an improved U-value but low visible light transmission (VLT) performance in comparison with low-emissivity double glazing windows. Thus, heating energy consumption was reduced, while as the electricity consumption for lighting was significantly increase. This increasement influenced the increase of the cooling energy consumption due to the higher indoor cooling load from lighting fixtures. To satisfy the 13% power generation efficiency suggested by the National Renewable Energy Laboratory, a VLT of 30% is required, which will produce energy savings of 4,861.44 ㎾h/year. For VLTs of ＞50%, energy saving is possible in combination with any generation efficiency.

A comparison between the daylighting and energy performance of courtyard and atrium buildings considering the hot climate of Saudi Arabia

Daylighting is a healthy and energy-efficient building design strategy that has increasingly attracted the attention of researchers. This study investigates daylighting and the energy performance of courtyard and atrium office buildings, considering different window-to-wall ratios (WWR) applicable to the hot climate of Saudi Arabia. In such a climate, it is recommended to reduce window area and use shading devices in addition to the shaded daylighting elements such as courtyards and atria. This study analysed several cases in this regard and found that the examined courtyard and atrium building configurations presented equivalent cooling and artificial lighting energy performance in general. As for daylighting performance, the most balanced option of those examined was the use of a moderate WWR value of 30%, given that shading devices were used. This moderate value provided a better balance between daylight availability and glare reduction. Increasing WWR to 40% or 50% would only increase cooling energy demand and visual discomfort through glare.

Optimization of passive design features for a naturally ventilated residential building according to the bioclimatic architecture concept and considering the northern Morocco climate

Improving the wellbeing of the occupants is the main challenge in the building design field. This work aims optimizing the design of a free-running residential building located in northern Morocco according to the bioclimatic architecture concept. In the first stage, an analysis of the bioclimatic chart has been done to find the best passive design strategies for the northern Morocco climate. Based on the results of the analysis, a set of passive design parameters has been selected to be considered in a building thermal and lighting energy performance optimization. A case study of a family detached residential building is considered for this purpose. The optimization problem is multi-objective, so the Pareto front approach was used to select the best design solution. Finally, a monthly assessment of the thermal and lighting energy performance of the chosen design solution is presented. The main results show that applying exterior insulation with a thick thermal mass layer is best for thermal performance enhancement. A wider glazed area with small overhang depth is more suitable for the south facade. For the east facade, the best solution is to limit the glazed area and increase the overhang depth. The importance of natural night ventilation for summer cooling has been also confirmed. This study can serve as a reference for building designers in northern Morocco while developing their projects.

Cool, photoluminescent paints towards energy consumption reductions in the built environment

Nowadays, passive strategies are identified among the preferred solutions to reduce energy consumption and to increase comfort in the built environment. Indeed, such strategies allow energy saving by exploiting the intrinsic characteristics of materials. In this work, an innovative cool, photoluminescent paint is considered for application in the built environment, as a passive strategy to (i) reduce energy for cooling in the hot season, (ii) maintain lower surface and air temperatures, thus benefiting comfort and (iii) contribute to the lighting of the outdoor public space. The cool, photoluminescent material is first described, then its implementation in the built environment is hypothesized. An experimental, in-lab characterization is conducted to measure the optics characteristics of the samples. Finally, possible implementation of the investigated material in the built environment is investigated by means of dynamic simulation, in terms of thermal- and lighting-energy performance, when applied on the external envelope of a case study building and as an advanced paving solution in a public space. Results from this preliminary study show that the investigated material has promising features, since it can save up to 30% energy for cooling and 27% yearly energy for lighting.

Gevo announces breakthrough development of renewable isoprene, a key chemical building block for producing rubber and rubber products

A movable shading device installed on an adaptive façade is able to change the positions of the shades according to the various control objectives (i.e. daylighting, thermal comfort, glare, energy, etc.) of the occupant. Since the key variables and the control method may change according to the control objectives, it is important to determine the hourly states of the shades in consideration of all of these factors. This study proposes a multi-purposes control strategy of adaptive facades for heating, cooling, lighting energy and glare. To depict the movements of the movable shading devices, the operable range is represented by an n number of fixed shade states having constant intervals. The control strategy entails deriving allowable shade states for glare prevention and energy conservation independently and then deriving the intersection range between the two shade state ranges. A case study was performed to verify the changes in hourly shade states and the energy performance of the envelope obtained by applying the proposed control strategy to an adaptive façade having a movable folding type shading device. The results of the case study show that hourly shade states were determined to satisfy the objectives of glare prevention and energy conservation simultaneously based on weather conditions and indoor requirement settings. From the case study, it can be seen that the proposed method can block the entry of direct solar radiation by lowering the unshaded fraction according to whether or not there would be discomfort glare while increasing the view factor in certain sections to promote the entry of diffuse solar radiation into the indoor space during the cooling and heating periods. The results of the case study also show that there can be large differences in the heating, cooling, and lighting energy performance of the building envelope for each orientation depending on the order of priority given to the objectives of the shading control, i.e. the objective of energy conservation only and the objective of simultaneous glare prevention and energy conservation. However, it was possible to effectively reduce the differences in energy proportions by adopting translucent shades.

A Study on the Lighting Energy Performance Analysis of a Shading Device based on Visual Comfort

A Study on the Lighting Energy Performance Analysis of a Shading Device based on Visual Comfort

Impact of bi-directional PV blind control method on lighting, heating and cooling energy consumption in mock-up rooms

As interest in the generation of renewable energy in buildings increases, shading devices do not limit its role in blocking the sunlight, but attach PV (photovoltaic) to blind slats for power generation. With this, there is also growing interest in how PV blind control can yield effective results on power generation and building energy consumption. The bi-directional control differed considerably from uni-directional control in the amount of PV power generation and inflow of skylight. However, the impact of lighting and air-conditioning energy consumptions by bi-directional PV blind control has not been evaluated. In this study, to identify the impact on energy performance of lighting, heating and cooling using bi-directional PV blind control, comparative measurement over the different seasons in two mock-up rooms was conducted. The energy consumptions of lighting and heating system using the bi-directional PV control were reduced by 4.62–35.50% and 2.10–11.46%, respectively, compared with those using the uni-directional PV blind control. In contrast, the energy consumptions of cooling system were increased by 6.25–14.29% due to the inflow of solar radiation. The bi-directional PV blind control can be mostly recommended throughout the year, except for clear and partly cloudy sky conditions during the summer, in the aspects of both PV power generation and energy consumption.

Optimisation of heating, cooling and lighting energy performance of modular buildings in respect to location’s climatic specifics

Abstract Off-site construction can represent a potential solution for worldwide mass housing demand and has gained a lot of attention during the refugee crisis in Europe. In particular, modular construction is one of the most cost-effective off-site methods for various types of buildings. Its characteristics are cost -effectiveness, quality control and quick on-site assembly. The design challenge is to join the stated advantages with operational sustainability, which is susceptible to climate-determined and energy efficient design. Therefore, the purpose of this paper was to systematically evaluate energy and visual (daylight) efficiency of singular prefabricated modular unit. In order to emphasise the relevance of local climate, modular unit model was analysed at five different locations, monitoring cooling, heating and lighting energy use. Results showed similarities and differences between the analysed locations and implemented design measures. The conducted analysis included variation of orientation, window to wall ratio, window distribution, envelope thermal transmittance and glazing characteristics. Surprisingly, the results indicate substantial impact of artificial lighting on the total energy use. Therefore, emphasising a direct connection to the Spatial Daylight Autonomy (sDA) values of the modular units. With sDA values below 50%, lighting can represent up to half of the total energy use.

Correlation of classroom typologies to lighting energy performance of academic building in warm-humid climate (case study: ITS Campus Sukolilo Surabaya)

Classrooms in educational buildings require certain lighting requirements to serve teaching and learning activities during daytime. The most typical design is double sided opening in order to get good daylight distribution in the classroom. Using artificial light is essential to contribute the worse daylight condition. A short observation indicates that during the lecture time the light turned on, even in the daytime. That might result in wasting electrical energy. The aim of the study is to examine the type of classroom, which perform comfortable lighting environment as well as saving energy. This paper reports preliminary results of the study obtained from field observation and measurements. The use of energy and usage pattern of artificial lighting during the lecture is recorded and then the data evaluated to see the suitability of existing energy use to building energy standards. The daylighting design aspects have to be the first consideration. However, the similarity in WWR of the classroom, the Daylight Factor (DF) may differ. It depends on the room depth. The similarity of the increase of WWR and Ratio of openings to floor area do not directly correspond to the increase of DF. The outdoor condition of larger daylight access and the room depth are the influencing factors. Despite the similarity of physical type, usage pattern of the classroom imply the use of electrical energy for lighting. The results indicate the factors influencing lighting energy performance in correlation to their typologies