Thermal Lighting Research Articles

Impact of Glazing on Thermal Comfort, Relative Humidity, and Lighting Level in Office Spaces

Belirli bir seviyeye sahip bir konfor duzeyi iceren bir calisma ortami saglamak bir ofis mekaninin en temel gerekliliklerinden birisidir. Aciktir ki minimum duzeyde bir mekan kalitesi elde etmek icin iliskili mekan parametrelerini saglayabiliyor olmak gereklidir. Bu acidan bina bilesenlerinin ic mekan ve hava kalitesine etkisi kritik duzeylere cikabilir. Bina formu, ve yonelimi ayni olsa bile konfor kosullari degisken olabilmektedir. Bunun yani sira, cephe duzeni de mekan konforu uzerinde bir etkiye sahip olmakla birlikte, isi, nem ve isik yogunlugu gibi parametreleri yakindan etkileyebilir. Bu sebeple, Ankara’nin Mustafa Kemal mahallesindeki uc farkli ofis mekani vaka olarak calisilmis ve ic mekan cevresel kosullari incelenmistir.

Changes in work conditions and impact on workers’ health: The case of collective syndrome in workers of a French administration office in March 2017

Introduction In early 2017, the Regional Unit of Public Health France was solicited for recurring symptoms, mostly irritations and headaches, affecting employees of a 400 people administration office. These symptoms had emerged with the relocation in a new building completely renovated that was characterized by low consumption mode and cumulative new working conditions (open space, reorganization of services). These events led to the evacuation of the building because of non-compliant indoor air analyzes. In order to identify the origin of this episode, surveys were conducted by a multidisciplinary group (epidemiology, occupational health, environment, socio-anthropology) following the recommendations of the National Public Health Agency for the management of unexplained collective syndromes. Methods In this study, three health components were investigated: the environment, the epidemiological context and the psychosocial context. Environmental expertise was conducted on indoor air quality, ventilation, acoustics and lighting. A retrospective cohort epidemiological survey was set up among the employees to characterize the health events in terms of people's time and working conditions (noise, lighting, open space…). Finally, an assessment of the psychosocial context was carried out on the basis of interviews with volunteer employees and through the development of a chronogram of events that occurred in recent months. Results Environmental expertise has revealed a poor ventilation system that may have degraded the quality of indoor air, insufficient thermal comfort, acoustic discomfort and lighting problems. As a result, 78% of employees were symptomatic within 6 months (from October 2016 to April 2017), with a higher attack rate among women (85% vs. 68%, P =0.009) and 89% of people with multiple episodes of symptoms. Individuals presented a variety of symptoms with a higher incidence of headache (58%), asthenia (56%) and eye stinging (42%). For more than 70% of them, the symptoms disappeared when they left the building and for more than 30% when they opened the windows. The occupational doctor registered 28 recognitions of occupational accidents. Problems related to the building (light, noise, ventilation, odors) were more often felt by the symptomatic people. In total, 71% of people were dissatisfied with the work in open-space, the main inconveniences mentioned being: difficulty of concentration, noise and lack of confidentiality. The interviews of the psychosocial component put forward various elements that could have favored the epidemic phenomenon, such as the disruption of the organization of work, a damaged and impersonal work environment or communication problems with management. Conclusions The various investigations led to the identification of many symptomatic people, although we cannot exclude some biases of information and selection, and allowed us characterizing these events as sick building syndrome. The occurrence of various and non-specific symptoms having the particularity of disappearing at the exit of the building, the large number of recurrent cases and the higher attack rate in women are characteristic of these episodes. There are also triggers at the environmental level such as insufficient ventilation and noise- or lighting-related annoyances. The new organization of work in open-space was also a particularly contributory factor. Recommendations on the technical points but also on the working conditions were developed in consultation with the management and will require a mid-term evaluation.

Implementing Sustainability in Retrofitting Heritage Buildings. Case Study: Villa Antoniadis, Alexandria, Egypt

Sustainable design is believed to stand on the opposite side of heritage conservation. This view is supported by the fact that sustainable design requires invasive measures to implement new technologies and treatments that challenge the principle of minimum intervention in heritage conservation. Another point of view sees heritage conservation as an already act of sustainable development that protects and preserves social and cultural resources such as heritage buildings and their intangible values. On the other hand, research and practice have proven that heritage buildings can be the subjects of sustainable design projects that achieve outstanding measures of sustainability and energy efficiency while not compromising the authenticity of the heritage value of the building. This sustainable conservation reaches its peak in adaptive-reuse projects of heritage buildings as reusing the building guarantees its ongoing maintenance and promotes its social, cultural and economic values to society, while giving it the ability to withstand modern users’ comfort and energy efficiency standards. This research presents a case study of the adaptive-reuse project of Villa Antoniadis in Alexandria; a heritage building built in the mid-nineteenth century and in the process of a major adaptive-reuse project. The history and significance of the building will be studied as well as the conservation values of the current project, then some proposals for interventions that could achieve more energy efficiency for the project while conserving the building are discussed. The research included a simulation of the building, using building energy modelling software for the current adaptive-reuse project as a base case, and the hypothetical application of different proposed sustainable interventions such as thermal insulation, double glazing, shading, lighting control, natural ventilation, and photovoltaic energy generation, where the energy savings potentials for each proposed intervention were studied. The simulation proved a possible reduction of 36.5% in the cooling, heating and lighting energy consumption as well as generated 74.7% of the energy required for cooling, heating and lighting from renewable energy sources.

Evaluation of energy efficiency and proposal of sustainable solutions for block E of the Fluminense Federal Institute Campus Campos Guarus

O modelo de desenvolvimento utilizado pela sociedade vem amplificando o uso de recursos naturais e, em consequência desse uso desproporcional, há impacto ambiental. Em vista disso, uma das soluções para amenizar os efeitos desse processo é a utilização eficiente desses recursos. Logo, a busca pela sustentabilidade alcançou o ramo da construção civil, por consequência estabelecendo metas para a eficiência energética. Este trabalho tem como objetivo avaliar a eficiência energética de uma edificação no Instituto Federal Fluminense Campus Campos Guarus. São abordados dois pontos principais: climatização e iluminação, já que se trata dos maiores consumidores de energia elétrica em uma construção. Esse documento utiliza metodologias previstas em Norma Técnica para cálculo da carga térmica e estudo luminotécnico. Dessa forma, são apresentadas soluções para melhorar a eficiência energética e as alternativas para otimização do consumo. Por fim, as propostas para melhoria no consumo são avaliadas pela viabilidade técnica e financeira. Assim, pode-se constatar a eficiência das lâmpadas LED (Diodo Emissor de Luz) em comparação às lâmpadas tubulares fluorescentes, e o superdimensionamento da carga térmica no bloco E.

A Laser Shadowgraphy Methodfor Studying Vibrations of Incandescent Solids

Abstract:This paper discusses a newlaser shadowgraphymethodfor investigating the in-plane vibration of refractory solid objects at incandescent temperatures.The method is applied whenever the use of Doppler laser vibrometer is inefficient due to small dimensions, high luminosity and poor reflectivity of the test object. We designed an experimental setup that included a modulatedlaser to backlight the vibrating object and to generate an analogue shadowgraph,a photo-detector installed in front of the shadowgraph, isconnected to a lock-in amplifier, and synchronized by the laser modulator,to retrieve the vibration signal from the noisy optical background. The methodwasapplied successfully to detect the resonance frequency of tungsten filament atincandescencetemperature inside an automotive lamp as a proof of concept. This method can be also adapted to test the thermo-elastic characteristics of refractory alloy samples,the mechanical properties of high temperature refractory MEMS lightingsandnano-structured tungsten based advanced thermal shock-resistant lighting sources.

Effect of Various External Shading Devices on Windows for Minimum Heat Gain and Adequate Day lighting into Buildings of Hot and Dry Climatic Zone in India

Glass is the major component of the building envelope to provide visual comfort to inside the buildings. In général clear and bronze glass was used as a main building envelope for both residential and commercial buildings to provide better day lighting into the buildings. If we use more glass area as a building envelope more radiation allows into the buildings. So that it is necessary to reduce more solar radiation and provide sufficient daylight factor inside the building's through glass windows with the help of external devices called shading devices. In this work four shading devices was tried on bronze glass window to find the heat gain and daylighting into buildings. This paper presents the experimental measurement of spectral characteristics of bronze glass which include transmission and reflection in entire solar spectrum region (300nm-2500nm) based on ASTM standards. A MATLAB code was developed to compute visible and solar optical properties as per the British standards. A building model was designed by design builder software tool. 40% window to wall ratio was considered for building models, thermal and day lighting analysis of buildings through windows was carried out in Energy plus software tool for hot and dry climatic zone of India.

Effect of Various External Shading Devices on Windows for Minimum Heat Gain and Adequate Day lighting into Buildings of Hot and Dry Climatic Zone in India

Glass is the major component of the building envelope to provide visual comfort to inside the buildings. In général clear and bronze glass was used as a main building envelope for both residential and commercial buildings to provide better day lighting into the buildings. If we use more glass area as a building envelope more radiation allows into the buildings. So that it is necessary to reduce more solar radiation and provide sufficient daylight factor inside the building's through glass windows with the help of external devices called shading devices. In this work four shading devices was tried on bronze glass window to find the heat gain and daylighting into buildings. This paper presents the experimental measurement of spectral characteristics of bronze glass which include transmission and reflection in entire solar spectrum region (300nm-2500nm) based on ASTM standards. A MATLAB code was developed to compute visible and solar optical properties as per the British standards. A building model was designed by design builder software tool. 40% window to wall ratio was considered for building models, thermal and day lighting analysis of buildings through windows was carried out in Energy plus software tool for hot and dry climatic zone of India.

Evaluation of Occupant Comfort in Office Buildings in Ghana

Occupant comfort, ranging from acoustic to thermal has been shown to affect health and work productivity in office buildings. Thus, the need to understand the link between these factors and work productivity considering Ghana’s recent growth in office infrastructure triggered by development in its economy cannot be overlooked. In this study, the office buildings of two institutions are evaluated based on eight categories of institution, age, gender, thermal, acoustic and visual comfort and other parameters such as smell and indoor aesthetics. Overall, 115 occupants responded to the survey questionnaire. The results show the female occupants more unsatisfied with certain parameters such as thermal comfort and lighting, compared to the males. Occupants above the age of 50 towards the retirement age of 60 were also satisfied with the acoustic and internal aesthetic of their workspace. The results serve as a guide to remodeling of any office space in line with improvements of the office building.

Analysis and Optimization using Renewable Energies to Get Net-Zero Energy Building for Warm Climate

Due to low energy price, economic optimization of consumption has no justification for users in Iran. Nowadays, the issue of ending fossil fuels, production of greenhouse gases and the main role of building in consumption of considerable amount of energy has drawn the focus of global researches to a new concept called net zero energy building. In this study, modeling, simulation and energy analysis have been used for considered building in Zahedan weather condition which has a dry and warm climate to draw the related equations and perform analysis. Multi-Objective optimization has been performed for simultaneous reduction of total energy consumption and total cost where the main decision making variables including thermal comfort, cooling, heating and lighting systems and other variables have been influential. The comparison of an ordinary optimized building and the intended optimized building which uses renewable energy resources indicates that it is possible to get to net zero energy building in addition to selling surplus 2 MWh electrical energy to electricity grid with simultaneous use of solar and wind renewable energies.

A Comfort Evaluation Method for Indoor Environment

Surveys reveal that modern people spend more than 90% of their life in an indoor environment. Therefore, the environments indoors have great influence on both the efficiency and body health on the occupants. Nevertheless, the impact of indoor environment on occupants can’t be measurement directly nowadays. An indoor comfort evaluation method is proposed in this paper based on the fuzzy AHP. Metrics such as thermal comfort and lighting comfort are considered. Our method is able to derive numeric values for indoor environment so that the occupants are capable of understanding the comfort index for their surrounding environment. Experiment results show that the system can effectively detect the parameters of the indoor environment thermal comfort, and make a quantitative display of the comfort via the fuzzy AHP algorithm. The system has some practicality in the construction of intelligent, air conditioning and other fields.

Impact of window to walls ratios on thermal comfort and energy consumption in tropical zone

This paper investigated the impact of Window to Wall Ratios (WWR) an the thermal comfort and energy lighting demand of a building in tropical zone. Simulations were carried out for a reference office proposed by Task 27 of IEA using three Window to Wall Ratios (WWR). Results were analyzed both in te

The impact of the spatial qualities of the workplace on architects' job satisfaction

Undoubtedly Job satisfaction among architects is necessary to create a healthy work environment and in turn supports the creation of meaningful built environments. This paper examines the phenomenon of job satisfaction amongst architects and the factors that significantly influence it in the context of Belfast, Northern Ireland, UK. A descriptive survey in the form of a questionnaire and structured interviews was utilized to form a comprehensive methodology for investigation, which was conducted in 2009. In total, three hundred questionnaires were administered, addressing architects working in both private and public sectors, while twelve interviews were conducted, with six for each sector. Preliminary findings indicate that job satisfaction has been rated to be relatively high amongst Belfast architects. Factors identified as particularly significant include control over thermal conditions, acoustics, views, lighting, and ergonomics.

Occupants' indoor environmental quality satisfaction factors as measures of school teachers' well-being

Most studies that investigated the impact of buildings' indoor environmental quality (IEQ) focused on office buildings, with those studying schools focusing on the impact on students' well-being rather than teachers'. Additionally, most of these studies limited their assessment of well-being to occupants' satisfaction with IEQ factors (e.g. thermal comfort and lighting), overlooking essential aspects related to psychological, social, and physical well-being. This paper presents results of a study conducted in 32 schools in Manitoba, Canada, to investigate the extent to which occupants' IEQ satisfaction factors can be used as measures of teachers psychological, social, and physical well-being. The study involved adapting, deploying and refining an existing IEQ satisfaction survey; and developing, deploying, refining and validating three new surveys to evaluate teachers' psychological, social and physical well-being in schools. Three existing validated well-being surveys in the literature for assessing generic psychological, social and physical well-being were also deployed with the other surveys to teachers in the 32 schools. The association analyses between these different surveys found ventilation and thermal comfort to be the most significant measure of teachers' physical well-being with moderately positive correlations, while lighting and acoustics and privacy were insignificant measures of well-being, thus reinforcing the need to distinguish between occupants' IEQ satisfaction and their well-being in future research. The newly developed well-being surveys include some factors not found in the existing generic well-being surveys and are therefore likely to produce the most representative assessment of teachers' well-being for detailed IEQ impact investigation.

The impact of working in a green certified building on cognitive function and health

Thirty years of public health research have demonstrated that improved indoor environmental quality is associated with better health outcomes. Recent research has demonstrated an impact of the indoor environment on cognitive function. We recruited 109 participants from 10 high-performing buildings (i.e. buildings surpassing the ASHRAE Standard 62.1–2010 ventilation requirement and with low total volatile organic compound concentrations) in five U.S. cities. In each city, buildings were matched by week of assessment, tenant, type of worker and work functions. A key distinction between the matched buildings was whether they had achieved green certification. Workers were administered a cognitive function test of higher order decision-making performance twice during the same week while indoor environmental quality parameters were monitored. Workers in green certified buildings scored 26.4% (95% CI: [12.8%, 39.7%]) higher on cognitive function tests, controlling for annual earnings, job category and level of schooling, and had 30% fewer sick building symptoms than those in non-certified buildings. These outcomes may be partially explained by IEQ factors, including thermal conditions and lighting, but the findings suggest that the benefits of green certification standards go beyond measureable IEQ factors. We describe a holistic “buildingomics” approach for examining the complexity of factors in a building that influence human health.

Modelling relationship among energy demand, climate and office building features: A cluster analysis at European level

More than one-third of the energy demand of industrialised countries is due to achieving acceptable conditions of thermal comfort and lighting in buildings. Energy demand in buildings depends on a combination of several parameters, such as climate, envelope typologies, occupant behaviour, and intended use. Indeed, assessing a building’s energy performance requires substantial input data describing constructions, environmental conditions, envelope thermo-physical properties, geometry, control strategies, and several other parameters. This has been a very active area of research in recent years, and several numerical approaches have been developed for building simulation; furthermore, most of these approaches have been tested and implemented in specialised software tools. However, the use of these tools poses many challenges in regards to the retrieval of reliable and detailed information, setting a steep learning curve for engineers and energy managers. It is often more convenient to have a simplified model that allows the evaluation of energy demand with a good level of accuracy and without excessive computational costs or user expertise. In this work, the authors extrapolate a set of simple correlations to permit a fast preliminary assessment of heating energy demand for office buildings. Data employed to build the correlations come from detailed dynamic simulations performed in TRNSYS environment. The models were built according to the standards and laws of building energy requirements in seven different European countries. For a more general assessment, the authors identified three cities for each country; for each location, three models with different shape factors were considered (S/V=0.24, 0.5 and 0.9). The results obtained from the simulations allowed for the determination of direct correlations among the thermal energy demand for space heating HDD and S/V values. In this way, the authors provided simple equations for a reliable and easy-to-use preliminary assessment of the energy demand of non-residential buildings to planners and designers, taking into account regulation dictated by law in each considered country.

Effects of different ambient environments on human responses and work performance

The increasing concern on intelligent lighting designs for better life quality calls for the studies on thermal lighting environments. Given this background, this study investigated the effects of various ambient environmental settings on the physiological responses, psychological responses and work performance of subjects. A total of eight male university students performed a non-work task (30 min) and a work task (60 min) in various thermal lighting environments. The experimental conditions included a combination of five correlated colour temperatures (CCT) and two indoor temperatures (Temp). The galvanic skin response, heart rate, skin temperature, subjective evaluations and work performance were measured. The results showed that the ambient environments of CCT5000 and CCT6500 °K at 30 °C and CCT4000 °K at 28 °C significantly affected subjects’ physiology and psychology in both work and non-work tasks. The future lighting environment designs may refer these findings of the present study.

208 LED照明機器における構造・光学連成解析技術の開発(GS1,3 材料力学・計算力学(1),研究討論セッション)

This paper discusses the method of illumination analysis by taking into consideration deformations of the lenses caused by environmental factors, especially for lighting devices using free-form surface lenses. A structure-optical coupled analysis is demonstrated to simulate a wide distribution lighting device at high temperature. First, deformations caused by high temperatures are simulated. Second, discretized surfaces are reconfigured to continuous surfaces by interpolation methods. Then the illuminance distribution is simulated using deformed surfaces and material characteristics at high temperature. As a result, it reveals that small deformations caused by thermal factors change lighting majorly.

FEATURES OF THE PRINCIPLE OF ERGONOMICS IN ARCHITECTURE AND DESIGN OF THE MODERN HOUSING

The present article considered and offered for the first time the principle of ergonomics, which defines the concept of architectural, design and technical equipment of internal vital housing spaces that are constructed under laws of ergonomics and takes into account characteristics of persona habitat space. Those characteristics are the thermal climate (composition of air, air temperature, and humidity of air), lighting, sound, information, safety and other parameters that determine architecture and design, that have esthetic value. Color, texture and materials have influence on behavior and emotional condition of the person’s personal harmony and comfort. The tendency of using new technologies during creation of architectural objects is connected with the new approach towards evaluation of environment’s value, preservation and energy consumption. The concept of formation of the "clever building" which represents the architectural object of new generation using technical innovations of the future - a difficult integrated ecological system, serves to increase of comfort of the inhabited environment and allows to save financial and energy resources. It opens broad prospects of positive influence on social living conditions, reduction of costs on electric power, improvement of ecological conditions.

The Influence of Solar Control Films on Energy and Daylighting Performance by Means of Experimental Data and Preliminary Unsteady Simulations

Solar control films were investigated as a strategy to improve thermal comfort, lighting conditions, and energy performance in non-residential buildings. The case study follows two adjacent similar offices with large window in the south-west façade of a building in Perugia, investigated by numerical and experimental approaches. The solar control films could strongly reduce the window heat gain (40-60%) and the indoor air temperature (1-1.5°C), whereas the daily average illuminance level was lowered by about 50-60%. Finally the yearly cooling energy demand decreases of about 25% (only South- West façade) and 39% (all the façades), whereas the heating energy demand increases of about 10-15% thanks to solar control films.

A longitudinal investigation of work environment stressors on the performance and wellbeing of office workers

This study uses a longitudinal within-subjects design to investigate the effects of inadequate Indoor Environmental Quality (IEQ) on work performance and wellbeing in a sample of 114 office workers over a period of 8 months. Participants completed a total of 2261 online surveys measuring perceived thermal comfort, lighting comfort and noise annoyance, measures of work performance, and individual state factors underlying performance and wellbeing. Characterising inadequate aspects of IEQ as environmental stressors, these stress factors can significantly reduce self-reported work performance and objectively measured cognitive performance by between 2.4% and 5.8% in most situations, and by up to 14.8% in rare cases. Environmental stressors act indirectly on work performance by reducing state variables, motivation, tiredness, and distractibility, which support high-functioning work performance. Exposure to environmental stress appears to erode individuals' resilience, or ability to cope with additional task demands. These results indicate that environmental stress reduces not only the cognitive capacity for work, but the rate of work (i.e. by reducing motivation). Increasing the number of individual stress factors is associated with a near linear reduction in work performance indicating that environmental stress factors are additive, not multiplicative. Environmental stressors reduce occupant wellbeing (mood, headaches, and feeling ‘off’) causing indirect reductions in work performance. Improving IEQ will likely produce small but pervasive increases in productivity.