No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
A statistical approach for the evaluation of thermal and visual comfort in free-running buildings
Abstract
In recent years, the study of indoor environmental comfort during the warm season has been one of the most attractive and hard tasks for architects and energy designers. Nowadays, thanks to the available high-performance utilities, the dynamic energy simulation of a building is relatively easy. Nevertheless, since it should simultaneously account for thermal, visual and air quality issues, a global approach, often neglected, becomes necessary.In the present work, an approach based on simple indicators calculated on a statistical basis will be presented; it can be useful for the simultaneous evaluation of the indoor thermal and visual comfort on a more comprehensive perspective, and it can be applied in any building energy analysis where a comparison between different solutions or strategies is required. At the end of the paper this approach is tested on a simple case study in order to show how the approach can be used to evaluate the influence of the size and the typology of a window on indoor comfort.
... To measure thermal discomfort, we follow the statistical approach proposed by Sicurella, Evola, and Wurtz (2012) that is a measure of how distant the operative temperature, T op , is from the limits of comfortable temperature range (T min and T max ). Sicurella et al. (2012) propose the Intensity of Thermal Discomfort (ITD) as the result of the integration of this difference over a period of interest. ...
... To measure thermal discomfort, we follow the statistical approach proposed by Sicurella, Evola, and Wurtz (2012) that is a measure of how distant the operative temperature, T op , is from the limits of comfortable temperature range (T min and T max ). Sicurella et al. (2012) propose the Intensity of Thermal Discomfort (ITD) as the result of the integration of this difference over a period of interest. The Intensity of Thermal Discomfort (ITD) is calculated as follows 1 : ...
... Zone 3 (z 3 ) applies for high FTD and low ITD, while zone 4 (z 4 ) indicates high FTD and high ITD. The zone's range is defined by taking the middle point from both FTD and ITD as suggested in Sicurella et al. (2012). As we compare various cases, for ITD, we take the maximum value obtained in all simulated cases (4.83 • C h /day). ...
Electricity consumption in buildings is especially relevant in hot and humid countries, where mechanical systems are frequently used to provide thermal comfort. In the context of school buildings, thermal comfort plays an important role in the learning process. Our aim is to explore natural ventilation to find passive, low-cost, realistic solutions to improve thermal comfort by combining design elements. For that, we assess four designs of doors (rectangular closed door, rectangular open door, half shutter door, half-door), four designs of windows (sliding window, sliding window with upper pivot window, sliding window with ventilated sill, and sliding window with upper pivot window and ventilated sill), and four building orientations (ventilated façade orientated towards north, east, south, and west.). A 4 3 factorial design of thermal simulations and 3-way ANOVA are conducted to evaluate the combined effect of the design elements on thermal comfort in a primary school classroom in Brazil's hot and humid climate. Statistics applied to the hottest scenario reveal that orientation, window, and the joint effect of windows and doors significantly improve thermal comfort. Our results reveal that standard window and door designs are ineffective in promoting natural ventilation in hot and humid regions. The ventilated sill, pivot window, and half-door appear as effective low-cost realistic solutions, decreasing the intensity and frequency of thermal comfort by up to 60% and 30%, respectively.
... >55% acceptance >75% preference [69] Frequency of visual comfort (FVC) [72] The percentage of annual occupied timesteps where the illuminance is within acceptable limits. ...
... E Under 150 -E Over 750 lx [72] The intensity of visual discomfort (IVD) [72] The time between the spatial average of existing illumination and the upper or lower limits of visual comfort. ...
... E Under 150 -E Over 750 lx [72] The intensity of visual discomfort (IVD) [72] The time between the spatial average of existing illumination and the upper or lower limits of visual comfort. ...
Visual comfort includes the ability to provide sufficient daylight without exaggeration. When daylight levels are insufficient inside a place or when daylight is intense, inhabitants experience visual discomfort. This study examines visual comfort in prayer halls by investigating the effectiveness of daylighting performance, including daylight amounts, such as illuminance level and daylight factor, and glare, including daylight glare probability, in different mosque morphologies. The evaluation had done by applying a quantitative method via the most recently updated daylighting simulation software using Autodesk-Insight-360 for Revit-2023 and SolemmaClimateStudio for Rhinoceros-6. Results show that mosques with courtyard lighting have reduced glare, and windows placed uniformly along the vertical axis get lots of natural light. The study concluded that levels of visual comfort in the prayer halls, in turn, vary according to mosques morphology. The current research contributes to detecting visual discomfort in mosque architecture based on differences in typological and morphological design characteristics.
... Additionally, a comparison is drawn between the methods used to estimate and predict visual comfort using mathematical equations (non-artificial-intelligence solutions) and machine learning methods (artificial intelligence solutions), as well as the number of parameters, the type of data used, and the results (prediction or real-time calculation). A statistical approach for the evaluation of thermal and visual comfort in free-running buildings was presented in [17]. The approach relied on the use of straightforward indicators to take into account the duration and intensity of potential discomfort. ...
... The method proposed in [17] for predicting and optimizing long-term visual comfort in daylit spaces is noteworthy for considering both instantaneous and cumulative visual comfort over time. Nevertheless, it heavily relied on detailed information about the building design, such as window orientation, shading devices, and other relevant features. ...
The accurate assessment of visual comfort in indoor spaces is crucial for creating environments that enhance occupant well-being, productivity, and overall satisfaction. This paper presents a groundbreaking contribution to the field of visual comfort assessment in occupied buildings, addressing the existing research gap in methods for evaluating visual comfort once a building is in use while ensuring compliance with design specifications. The primary aim of this study was to introduce a pioneering approach for estimating visual comfort in indoor environments that is non-intrusive, practical, and can deliver accurate results without compromising accuracy. By incorporating mathematical visual comfort estimation into a regression model, the proposed method was evaluated and compared using real-life scenario. The experimental results demonstrated that the suggested model surpassed the mathematical model with an impressive performance improvement of 99%, requiring fewer computational resources and exhibiting a remarkable 95% faster processing time.
... Specifying the over lit areas can also suggest direct light discomfort risk. • Frequency of Visual Comfort (FVC): percentage of time within the analysis period during which appropriate values of average illuminance are accomplished [61]. Similar to UDI, proposes 3 ranges: Comfort, Under and Over. ...
... E Under/Over : minimum/maximum illuminance threshold E Daylight : computed/measured illuminance value t: analysis period • Intensity of Visual Discomfort (IVD): time integral of the difference between the spatial average of the current daylight illuminance and the upper limit of visual comfort or the lower limit of visual comfort [61]. ...
Visual comfort can affect building occupants’ behaviour, productivity and health. It is highly dependent on the occupant and how they perform a task indoors. In that regard, an occupant centred approach is more suitable for evaluating the lighting perception of the indoor environment. Nevertheless, the process of rating and estimating the visual comfort makes a limited distinction between physiological differences (e.g., ageing eye, light sensitivity), field of view, and personal preferences, which have been proven to influence the occupants’ lighting needs to complete their tasks. Such features were not considered while establishing the visually comfortable conditions; perhaps due to the challenge of coupling the assumptions made during building design to the performance indicators monitored during building operation. This work focuses on reviewing literature findings on how the common design approach deviates from real building performance, particularly failing to prevent visual disturbances that can trigger the inefficient operation of building systems. Additionally, it is highlighted that redesigned visual comfort assessment methods and metrics are required to bridge the gap between the lighting environment ratings computed and surveyed. One possibility is to consider such physiological features that induce lighting experiences. Finally, it was deducted that it is important to target the occupants’ eye response to calibrate limit thresholds, propose occupant profiling, and that it is convenient to continuously monitor the occupants’ perception of indoor lighting conditions.
... Similar to UDI concept, Frequency of Visual Comfort (FVC) is the time fraction (ti) in percent over a given period that illuminance (Edaylight) values are within a specific range to ensure visual comfort regarding daylight only as shown in Eq. 7 [65]. This means visual comfort is guaranteed when illuminance is not below EUnder or above EOver, while the main difference with UDI is the measuring approach of illuminance level, in which UDI counts on spatial rendering in each analysis point, while FVC proposed an average daylight illuminance that hinders its applicability in shares zones. ...
... The average daylight illuminance was not only the focus of FVC (Fig. 17), but also Sicurella et al. [65] introduced Intensity of Visual Discomfort (IVD) as "the time integral of the difference between the spatial average of the current daylight illuminance and the upper limit of visual comfort (Eover = 750 lux) as IVDover or the lower limit of visual comfort (Eunder = 150 lux) as IVDunder". As a result, IVD can assess both natural light penetration and visual discomfort simultaneously, while it is difficult to obtain zero IVD during a long period. ...
Exposure to daylight significantly affects the psychological well-being of occupants by diminishing headaches, eye tensions, or stress. Daylight penetration is a matter of collaboration between building façade and perimeter zones that can be controlled through façade design features. This study reviews available daylighting systems to block or redirect natural light inside the space and their overall performance. Adaptation found to be the main key feature of daylighting systems to improve their effectiveness in indoor environments. As the main implication of such systems on the visual comfort performance of occupants, a list of quantitative indices is studied based on their mathematical equation to outline their advantages and limitations. Findings revealed a lack of agreement on acceptable indoor illuminance thresholds for most of the indices and the absence of a reliable glare index in presence of sun within the view field of the occupant. Similarly, many green building certifications propose a specific criterion to assess view out but remained a challenge for future studies.
... Secondly, in order to evaluate thermal comfort degree during the cooling season (summer). The following new indicator called Intensity of Thermal Discomfort for overheating (ITD over ) [10] is considered. It defined as the time integral of the positive difference between the current indoor temperature and the upper threshold for the comfort temperature (24°C). ...
... Yassine Kharbouch et al. / Energy Procedia 139 (2017)[10][11][12][13][14][15] ...
... Visual Comfort Metric Symbol Category [267] Illuminance E (lx) Amount of light [267] Illuminance uniformity U [267] Luminance L (cd/m 2 ) [267] Luminance ratio LR [268] Scotopic/Photopic ratio S/P ratio [269] Color Discrimination Index CDI Color rendition [270] Color Preference Index CPI [271] Color Rendering Capacity CRC [267] Color Rendering Index CRI [272] Color Quality Scale CQS [273] Feeling of contrast Index FCI [274] Flattery Index [275] Gamut Area Index GAI [276] Memory color quality metric S(a) [277] Pointer's new color rendering index [278] Annual Sunlight Exposure ASE Daylight availability [279] Continuous Daylight Autonomy cDA [280] Daylight Autonomy DA [281] Daylight Factor DF [282] Frequency of Visual Comfort FVC [282] Intensity Visual Discomfort IVD [278] Spatial Daylight Autonomy sDA [283] Useful Daylight Illuminance UDI [284] British Glare Index ...
... Visual Comfort Metric Symbol Category [267] Illuminance E (lx) Amount of light [267] Illuminance uniformity U [267] Luminance L (cd/m 2 ) [267] Luminance ratio LR [268] Scotopic/Photopic ratio S/P ratio [269] Color Discrimination Index CDI Color rendition [270] Color Preference Index CPI [271] Color Rendering Capacity CRC [267] Color Rendering Index CRI [272] Color Quality Scale CQS [273] Feeling of contrast Index FCI [274] Flattery Index [275] Gamut Area Index GAI [276] Memory color quality metric S(a) [277] Pointer's new color rendering index [278] Annual Sunlight Exposure ASE Daylight availability [279] Continuous Daylight Autonomy cDA [280] Daylight Autonomy DA [281] Daylight Factor DF [282] Frequency of Visual Comfort FVC [282] Intensity Visual Discomfort IVD [278] Spatial Daylight Autonomy sDA [283] Useful Daylight Illuminance UDI [284] British Glare Index ...
Today, the effects of the indoor environment on occupants’ health and comfort represent a very important topic and requires a holistic approach in which the four main environmental factors (thermal comfort, air quality, acoustics, and lighting) should be simultaneously assessed. The present paper shows the results of a literature survey that aimed to collect the indicators for the evaluation of occupants’ health and comfort in indoor environmental quality evaluations. A broad number of papers that propose the indicators of a specific environmental factor is available in the scientific literature, but a review that collects the indicators of all four factors is lacking. In this review paper, the difference between indicators for the evaluation of risk for human health and for comfort evaluation is clarified. For each environmental factor, the risk for human health indicators are proposed with the relative threshold values, and the human comfort indicators are grouped into categories according to the number of parameters included, or the specific field of application for which they are proposed. Furthermore, the differences between human health and comfort indicators are highlighted.
... ASHRAE 55 also proposes the use of the 90% percentage as requirement in order to acquire a higher standard of thermal comfort. Thus, taking into account the definition of comfort temperatures, the thermal performance evaluation of simulated environments was based on indicators in accordance with the statistical approach to thermal comfort proposed by Sicurella, Evola and Wurtz [31] and adapted in other Brazilian studies by Nico-Rodrigues et al. [32], who analyzed changes in operating temperatures during the 24 hours of the day. ...
... Source: adapted from Ref. [31]. graph [29], resulting in the comfort temperature range for the period in question, considering a value of 90% of acceptability. ...
... The targeted indoor conditions were defined as the fixed range of indoor operative temperatures for summer and winter seasons. Sicurella et al. [39] introduced a series of indicators to measure the visual and thermal comfort in free-running buildings. The indicators chosen to measure the thermal comfort includes frequency of thermal comfort (FTC) and intensity of thermal discomfort (ITD). ...
... Here, it was possible to notice that the PCMCB refurbishment in the test huts had a major effect on reducing the intensity of thermal discomfort, whereas its occurrence was still remarkable. Similar observations have been made by Sicurella et al. [39] and Castell et al. [48] for the effect of glazed area and PCM incorporation, respectively, in buildings. While the ITDover explains how far the indoor environment from comfort conditions changes, the FTDover gives a summarised output on whether thermal comfort conditions are met. ...
This paper investigates the potential of using form-stable phase change material (FS-PCM) integrated cement mortars in building envelopes to prevent overheating and to improve summer thermal comfort. The FS-PCM integrated cement mortar was applied as the interior surface plastering mortar of a full-scale test hut and compared with identical test huts built on cement plasterboard (OCB) and gypsum plasterboard (GPB). The test huts were exposed to outdoor climatic conditions, and indoor thermal behaviours were continuously monitored throughout the summer period. The effects of PCM in reducing the overheating was analysed by the intensity of thermal discomfort (ITDover) and frequency of thermal discomfort (FTDover) for overheating during the summer days. The comparison between different test huts showed that the application of PCM integrated cement mortars reduced the peak indoor temperature by up to 2.4 °C, compared to GPB and OCB test rooms. More importantly, the analysis of overheating effects revealed that at lower intensive thermal discomfort levels, FS-PCM largely reduces FTDover. As the intensity of thermal discomfort increases, the reduction in ITDover becomes dominant. At highly intensive thermal discomfort levels, the reduction was neither apparent in the intensity of thermal discomfort nor the period of discomfort.
... Secondly, in order to evaluate thermal comfort degree during the cooling season (summer). The following new indicator called Intensity of Thermal Discomfort for overheating (ITD over ) [10] is considered. It defined as the time integral of the positive difference between the current indoor temperature and the upper threshold for the comfort temperature (24°C). ...
... Yassine Kharbouch et al. / Energy Procedia 139 (2017)[10][11][12][13][14][15] ...
Our study focuses on thermal performances evaluation of a solar room built using a new bio-based composite wall coupled with a phase change material (PCM) layer during the cooling season under climatic conditions of Nancy city in France. This composite wall consists of a bio-based panel IBS-IZOLOX developed by the Belgium company ISOLHABITAT. The inner side of this bio-based composite wall should be coupled with a PCM layer in order to improve the thermal inertia of the room envelope. The results show that this system wall can improve significantly the thermal comfort performance of the solar room during the cooling season.
... Only occupation hours are considered. Two types of indexes are defined, based on Ref. [60]: ...
... Only occupation hours are considered. Two types of indexes are defined, based on Ref. [58]: ...
Post-insulating existing buildings is a promising solution for reducing operational CO 2 emissions of the European built environment. Nonetheless, its efficacy is unclear when traditional and historic massive walls are considered, especially in Southern Europe. This study employs a validated and calibrated dynamic hygrothermal simulation model to assess indoor comfort and energy demands in a public library with thick stone masonry walls and intermittent occupation, considering three Southern European climates: Porto, Lisbon, and Bologna. Five insulation materials, including three thermal mortars and two conventional materials (Hydrophobic Mineral Wool and Expanded Polystyrene), are compared using internal and external insulation solutions. Thin insulation systems (4cm) with moderate thermal resistance (R t = 0.3-1.0 m²K/W) are studied and found to provide more benefits than drawbacks. One thermal mortar-based system demonstrates comparable performance to conventional insulation materials, indicating that low-conductivity thermal mortars are effective for retrofitting historic and traditional massive walls. Numerical analyses show that optimal reductions of energy demand can be achieved with an insulation R t of 0.9-1.3 m²K/W, while further increases yield no additional benefits and even counterproductive outcomes. Results supports adopting moderate R t insulation Southern European climates and highlights the need for future research considering the effect of post-insulation on climate change adaptation.
... The visual comfort is ensured completely by daylight without any artificial lighting. The range between 750 lx (no excessive daylighting and no possibility of glare) and 150 lx (sufficient daylighting and no artificial illumination) was assumed [34]. In this study, the targeted indoor illuminance values are within UDI 150$750 lx . ...
Different shading device systems and control strategies can be employed in different parts of a window system to perform different functions, particularly for fully glazed façades. A split louver with various improvements was proposed in this study as an innovative daylighting device to improve daylighting distribution and uniformity. An 8 m deep office room in Jordan was chosen for a case study, where it is south-oriented with a high window-to-wall ratio (WWR: 95%). The split louver system features two sections with different functions that can affect the quality and quantity of daylighting performance in the deep room space. Four types of parametrically controlled reflective slats, i.e., unanimous, incremental, fully parametric, and parametrically incremental, were investigated for the upper section of the split louver. While the daylighting performance of the four systems is extremely similar in terms of illuminance level but different in distribution, the parametrically incremental control is the preferred one attributed to its practicality and distribution performance. The upper section of the split louver includes blind integration, and different slat surface materials (diffuse, semi-mirrored, and mirrored) were evolved through various improvement phases. Simultaneously, the lower section of the split louver was investigated in order to adjust the overall illuminance level. The proposal of scheduled angles of split louver in both sections presented the most optimal combinations to achieve balanced daylighting levels in both the front and back of the space. This resulted in a free-glare indoor with accepted daylight uniformity levels of up to 0.60 and high percentage coverage within UDI150∼750 lux for most of the working hours throughout the year are realized (between 90% and 100% at noontime and no less than 50% along the rest of the working hours).
... Overall, the description of visual comfort is less standardized than the more famous thermal comfort. There are multiple reasons for this: it is clearly dependent on the outdoor illuminance levels, type of window frame/glazing, type of visual task or characteristics of the indoor space (e.g., reflectance coefficients) [25]. The Standard EN 1264-1 establishes the fundamental rules for artificial lighting in indoor workplaces, including schools, and tackles the glare issues, encouraging the integration between natural and artificial lighting [26]. ...
Taken as a whole, the indoor environmental quality (IEQ) is a concept that deals not only with thermal conditions, but it also goes much further, because it includes indoor air quality (IAQ), illuminance or acoustic comfort. Among the different categories of buildings, schools are one of the most important in society especially because future generations are spending more than 6 h/day and ensuring them a healthy and comfortable environment must be top priority. The purposes of this research were to better understand school children’s IEQ preferences and needs in classrooms and to compare these among rural versus urban respondents. To reach this goal, a simple yet complete survey was proposed and, along with measurements, multiple conclusions were made. The methodology proposed was to reach a large sample of respondents to give more credibility and precision to the analysis. The results are based on the responses of 790 occupants both from urban and rural environments. Lack of ventilation, cooling, low or too high temperatures during winter/summer periods and a misappropriate sizing or piloting of the heating system are some of the issues found during the survey. The paper tackles several issues at once, helping to paint a more holistic image of the problems encountered in school classrooms. Optimal thermal comfort is not met during the cold season in any of the schools under investigation. The old rural schools were found to be the worst performing buildings compared to urban schools where due to recent investments in refurbishment the winter thermal comfort was enhanced. During the study, it was observed that one of the major IAQ problems consisted in elevated levels of CO2 or particulate matter especially for the schools situated in the city. Noise was reported as an issue only for the schools situated next to national roads while visual comfort was found to be acceptable for more than 94% of respondents from all regions.
... Regarding the contribution of daylight to the thermal load of indoor spaces, when ingress of direct sunlight is not controlled, excessive solar gains increase the risk of overheating and subsequent energy consumption for cooling, particularly during the summer season (Sicurella et al., 2012). In the move toward low carbon school designs, balancing the conflicting effects of daylight on building energy will become increasingly challenging (Jenkins et al., 2009). ...
Research confirms that daylight is important not only for vision, but also for general well-being. Little is known, however, about how real world occupied spaces perform in terms of daylight. This holds true particularly in schools, where practicalities prevent the collection of data from classrooms in use.
The framework presented here addresses the lack of daylighting performance evidence from the real world, necessary for guiding daylighting predictions for classroom design. It describes and prototypes a methodology that achieves long-term daylighting performance monitoring in classrooms in use. This methodology also enables the observation of actions the occupants take to sustain or improve their visual comfort.
Four UK secondary school classrooms were used as case studies and were monitored for up to a year. A mixed method approach was taken in order to associate measured luminance, a physical characteristic of light, to user interaction with electric lights and blinds, as well as student subjective responses.
This resulted in two novel fine-grained year-long datasets, as well as a record of student appraisals of the luminous environment. The luminance dataset contains over a trillion measurements captured on-site simultaneously for multiple (nearly 18,000,000) points in space, at a 10-minute frequency over a year, resulting in multiple (over 62,000) points in time.
Application of the long-term monitoring method was found to be robust and useful for monitoring complex multi-user spaces for at least six consecutive months. Combining fine-grained luminance mapping, records of occupant interactions with design elements and occupant subjective views of the case study classrooms provided a better understanding of the many factors that shape operational daylighting performance. This was achieved by identifying specific parameters, examining their effect across a set of the three types of evidence and highlighting the complex relationships detected between them.
The three aspect framework presented here contributes to a philosophy of research that addresses real world challenges by combining their technical, behavioural and subjective expressions. In doing so it supports the view that sustainable and thus effective solutions are those that stem from holistic people-centred interdisciplinary research.
... Temperature and illuminance are the two most essential physical factors for indoor thermal and visual comfort. 25 In this study, two conflicting indicators were utilized to define the optimal trade-off result for lessening TEP for thermal comfort and maximizing OIPs. Thus, OIPs and TEP assessments for optimization were made using the criteria of Table 1. ...
The study aims to investigate the preferred daylighting availability ranges for the best visual and thermal comfort in office workspace through optimal modifications light-shelve parameters, grounded on parametric design and optimization, with a focus on its visual and thermal indices. To identify the final optimal solutions, single and multi-optimization scenarios were used. The findings revealed that optimizing for a single objective might obstruct the attainment of other goals. In other words, the first scenario, optimization only for daylight availability, results in an increase in temperature. While optimizing for indoor thermal performance solely, none of the preset daylight availability acceptance requirements were met. However, multi-objective optimization solutions were the final optimal solutions nearest to the ideal. Final optimum solutions of the best design parameters of light shelves can improve the total average of daylight availability by 56.25%, 50.63%, 57.50% and 71.88%, and the indoor thermal performance was improved by decreasing the average temperature for thermal environmental performance indicators by 4.15%, 3.27%, 3.17% and 4.76%, respectively, in March, June, September and December. The study concludes that daylighting levels of 500 lux to1300 lux provide the best range of optimal daylighting for visual and thermal comfort indicators for office spaces in the tropics.
... Hence, it is reasonable to argue that the built environment is supportive of the mental, psychological, and emotional functions of people. Many studies have revealed that green buildings tend to be better at saving energy and water, bill saving, and improving quality of life [28,29]. ...
A series of international conferences and initiatives, such as the Habitat III New Urban Agenda and UN Sustainable Development Goals, have urged industry, scholars, and policymakers to create an inclusive and sustainable built environment for all in the coming era of cities. Green building schemes, which have been gaining momentum over recent decades, are one of the most influential measures that have been taken to promote urban sustainability. However, due to disciplinary characteristics, most current studies share a techno-engineering focus. Seldom do they answer the question: will green buildings make a difference to the occupants? This paper explains how, and to what extent, green features and design contribute to different dimensions of occupant well-being by conducting a systematic and comprehensive review of current journal articles and industrial reports. It provides an alternative, occupant-oriented perspective to the conventional discourse. A conceptual framework is developed, revealing that green building aspects are linked to six dimensions (three subjective and three objective) of occupant well-being. It further shows how different green features are linked with these dimensions through a detailed examination of the literature. Finally, suggestions are provided based on the research findings for the direction of future green building development and empirical research.
... This has geared the attention of researchers towards the study of algorithms and techniques such as simulation and the measurement of the level of thermal comfort in green buildings as compared to conventional buildings. The range of room temperature can now propose which dependents on some factors such as physiology, psychology, culture and the behaviour of the building occupants [47,24,23]. ...
The construction sector offers numerous advantages to the world. Some of which include the provision of buildings, streets, tunnels etc. The change in climate is one of the many challenges in this dispensation which requires that techniques and strategies should be developed for the purpose of efficient energy supply. This brings into light the need to design methods for the calculation of energy use in buildings. A few empirical research has been conducted concerning the study of the causal links between urban growth and the consumption of electricity in the specific case of Ghana. It has been found out that the insulation of walls and ceiling has the tendency to reduce building energy consumption by 70-80% and 65% respectively, as compared to a building of the same type and material but without insulation. The climatic condition of Ghana is such that the southwestern part is hot and humid and the northern part experiences a hot and dry climate and has a warm eastern coastal belt. In simple term, Ghana is a hot temperate zone. Nonetheless, the climate varies with time. It is therefore paramount to introduce building insulators to reduce the energy requirement of the buildings especially in the residential sector of the country. This paper will therefore consider the introduction of thermal insulation on building façade in Ghana and the mathematical model to achieving optimum thickness suitable for a particular region or city. The mathematical model for determining the threshold values for CDD and HDD is also considered.
... According to the heat-color hypothesis, visual and heat perception affect each other (Heijs and Stringer, 1988). The most important physical parameters for thermal and visual comfort are temperature and illuminance (Sicurella et al., 2012). ...
The accurate prediction of the visual comfort zone in an indoor environment is difficult as it depends on many parameters. This is especially the case for large compact urban areas in which the density and shadow from neighboring buildings can limit the accessible daylighting in indoor spaces. This paper investigates the satisfaction range for illuminance regarding indoor air temperature in office buildings and the significant parameters affecting this range in six office buildings in Tehran, Iran. Lighting comfort has been evaluated by a subjective survey (509 total responses) and field measurement. The questionnaires were filled out in 146 and 109 rooms in summer and winter, respectively. The results show that the illuminance should not be less than 550 lx, while illuminance between 600 and 650 lx provides the highest satisfaction level. The satisfaction with lighting level is affected by individual parameters such as age, type of activity, and environmental parameters such as window orientation, external obscurations, and season. A relationship was observed between lighting level satisfaction and thermal condition acceptance, and the overall comfort depends more on thermal conditions than the lighting level.
... Third, the study has examined one aspect of the visual environment which is related to the light level. However, visual environment is a subjective measure that can be affected by several other metrics such as glare [11,18,66,101] and distribution [11,18]. ...
Indoor Environment Quality (IEQ) is grouped into four main categories: thermal comfort, indoor air quality (IAQ), visual and acoustic comfort. Individual aspects of IEQ are investigated to examine their impact on children's overall comfort in primary schools in the UK. This study has surveyed 805 children in 32 naturally ventilated classrooms during non-heating and heating seasons. This study has calculated the proportion of comfort votes by individual aspects of IEQ, predicted comfort votes by multilinear regression model and estimated the probability of having uncomfortable votes by binary logistic regression.
Results of this study highlight that the proportion of uncomfortable votes should be kept below 10%. The developed multilinear model suggests that for a unit change in Air Sensation Votes (ASVs) and operative temperatures (Top), comfort votes change by 0.28 and 0.12, respectively. Developed multilinear and logistic regression models show that ASVs have a more significant impact on overall comfort than Top. To achieve acceptable comfortable votes and keep the probability of having uncomfortable votes below 10%, ASVs and Top should be kept within these limits: [ASV = very fresh and Top = 19–27 °C], [ASV = fresh and Top = 19–24 °C], and [ASV = OK and Top = 19–22 °C]. The ranges suggest that better perception of IAQ makes up for higher temperatures. It is advised to maintain individual aspects of IEQ, however, dissatisfaction with one aspect of IEQ does not necessarily result in overall discomfort unless that aspect is extremely unacceptable. Investigating the most influential factors on occupants’ comfort suggests which building controls should be prioritized for designers.
... Sicurella et al. [99] compared several thermal and visual comfort indicators using statistical approach. They made a combined evaluation of thermal and visual comfort in buildings and found that the use of low emissivity glazing did not produce any visible changes on Top and average luminance in comparison to a normal glass. ...
The definition of a good indoor climate is vital for the success of any building. This will make the occupants comfortable and also will decide the energy use pattern in the building thereby influencing both its economy and sustainability. Fanger’s predicted mean vote (PMV) model is often used to estimate the comfort requirements for a building. However, recent studies suggest that the PMV model frequently either overestimates or underestimates the thermal sensation in warmer or cooler climate, respectively. This leads to a prediction of a lower set point temperature in warmer condition and higher set point temperature in cooler condition, than required, which is energy consumptive. In the field survey based comfort studies the adaptive opportunities undertaken by the subjects are accommodated, which gives a true picture of the indoor conditions. In this research, a year round survey was conducted following ASHRAE class II protocol in 10 naturally ventilated buildings of different types in the Darjeeling Himalayan Region. The buildings are situated at 5 (five) different locations having different elevation from the sea level. An overall of 2608 responses of thermal comfort were gathered from 436 subjects in the 12 months of survey, all of whom participated voluntarily.It was seen that the clothing insulation showed a significant increase with the elevation of the locations, whereas the comfort temperature showed a significant decrease with the elevation of the location. Two models are proposed, first the variation of indoor comfort temperature with the outdoor environmental condition and secondly, the variation of indoor comfort temperature with the elevation of the location. The research being first of its kind in the region is expected to be of help to building designers, architects and engineers for determining comfort conditions of indoor environment in the region or region elsewhere having a similar bioclimatic set up.
... Overlit reports illuminances that exceed ten times the target illuminance, equivalent to 3000 lx, for at least 5% of the annual occupied timesteps (DAv3000/5%), indicating potential thermal and visual discomforts [237]. The 5% threshold is attributed to thermal assessments, stated by The idea of FVC is similar to UDI, but with different thresholds, as Sicurella et al. [247] studied spatially averaged illuminances, rather than distributed, to avoid too high or too low local values. IVD consists of two metrics: IVDOver and IVDUnder, reported as the time difference between the spatial average of current daylight illuminance and the upper limit of visual comfort (EOver) or its lower limit (EUnder): ...
Daylighting is a parallel universe to Architecture, where architects benefit greatly from daylight prediction techniques, which have witnessed a paradigm shift from simple methods to more sophisticated computational simulation tools. Still, such accumulating complexities made many designers disinclined to integrate what they consider difficult methods into their practices, even hindered the casual use of simulation tools, due to the lack of essential knowledge, among other complications. Herein, this research aims to provide a comprehensive review of over 100 years of growing fundamental directions to predict the amount of daylight inside buildings, with a particular focus on tracing sky models, weather datasets, building geometry and daylight calculation methods, which drove the progress of performance metrics and simulation tools, considering detailed descriptions of 50 prevalent simulation tools. This historical review is conducted with the architects’ nature in mind to underline existing knowledge gaps in the research domain and reveal future perspectives. Another implication of this research is to remove ambiguity of unfamiliar terms and technicalities, helping practitioners, especially young architects, of different backgrounds and expertise to grasp the essential daylight-related topics, guiding their decisions on suitable tools to use in building design.
... Occupant productivity in commercial buildings such as offices is a key concern that depends on the indoor environment quality [34,35]. It has been measured through surveys to determine visual comfort from those occupants [36][37][38][39]. ...
Double-skin perforated sheet façades, enclosures consisting of perforated screens, air chambers and glass/wall sheets, are features of modern building design that are winning greater acceptance. A detailed analysis of their suitability across Europe is first performed here. A reference building both with and without the protective double-skin perforated sheet envelope is subjected to a comparative test of solar energy gains with regard to the environment. Additionally, the results of a preliminary survey are presented on the visual perceptions of different patterns of perforated metal sheets. Then the behaviour of these configurations is addressed, through a complete “Energyplus® model” (design builder). A test campaign on a reference perforated screen mounted on a service building of reference was fully monitored over one year, supported by thermographic data recorded for additional validation purposes during the same period. The new parametric energy assessment takes additional variables into account, such as orientation and location of the façade, demonstrating that the real performance for such enclosures greatly depends on them. Accordingly, the influence of different combinations of perforated screens on cooling, heating and lighting loads demonstrates the suitability of a previously optimized configuration in terms of relative energy savings.
... Performance characteristics of different types of shading devices were reviewed using previous studies. The authors noted that the performance of shading devices depends on parameters like climate, occupancy, mechanical and electrical systems, design problems, energy efficiency issues, etc. Literature depicts that the study related to shading devices is majorly analyzed in terms of lightning [80][81][82][83] and thermallightning [84][85][86][87][88] . However, the shading technique can be effectively analyzed as a passive cooling technique if thermal perfor-mance evaluation is carried out prior to lightning performance evaluation. ...
... First, researchers have rarely investigated three IEQ physical factors (i.e., lighting, thermal, and indoor air quality) together [18]. Some researchers have assessed two out of the three indoor environmental quality metrics (e.g., lighting and thermal) for integrated design [19][20][21]. Others have focused on the simultaneous evaluation of one or two physical factors and energy performance [22][23][24][25][26]. ...
... Common glare metrics such as Unified Glare Rating (UGR) cannot be applied for daylight glare as the glare sources (windows) are usually very large. Several methods for daylight glare rating were introduced in the last time, such as CIE unified glare rating [26], daylight glare probability (DGP), annual enhanced simplified DGP [27], and intensity of visual discomfort (IVD) [28]. The criteria of DGP based on annual glare investigation are computationally expensive. ...
... First, researchers have rarely investigated three indoor environmental quality (IEQ) physical factors (i.e., lighting, thermal, and indoor air quality) together [18]. Some researchers have assessed two out of the three indoor environmental quality metrics (e.g., lighting and thermal) for integrated design [19][20][21]. Others have focused on the simultaneous evaluation of one or two physical factors and energy performance [22][23][24][25][26]. ...
... On this basis, this paper adopts an indicator called Intensity of Thermal Discomfort (ITD). The ITD has been introduced by the authors in a previous paper (Sicurella et al. 2012), and is defined as the time integral of the positive difference between the current operative temperature and the upper threshold for comfort: ...
The incorporation of Phase Change Materials (PCMs) into the opaque envelope of lightweight buildings is a good solution to compensate for the small thermal inertia, which usually entails pronounced overheating and high space cooling load in summer. However, the position and the thickness of the PCMs, as well as their thermal properties, must be attentively selected in order to ensure their effective operation. This paper shows a comprehensive investigation about the effectiveness of a commercial PCM, available in the form of mats, when installed within drywall partition systems in air-conditioned lightweight office buildings. The study is based on dynamic simulations carried out with EnergyPlus on a typical office building, with the aim to calculate the indoor operative temperature and the cooling load under thermostatic control. The performance for the base case (without PCM) is then compared with the case where PCM mats with various thickness and melting temperature are applied. The analysis is repeated in three different locations, ranging from Southern Europe (Rome, Italy), Continental Europe (Wien, Austria) and Northern Europe (London, UK). The results of the simulations highlight that in lightweight air-conditioned office buildings PCMs contribute to attenuate the inside surface temperature peak by around 0.5 °C, while also reducing the peak cooling load by 10% or even 15%, depending on the PCM thickness and on the outdoor climate. The conclusions may help designers to make the correct choices in terms of thickness of the PCMs, scheduled rate of nighttime ventilation and value of the peak melting temperature.
... Secondly, in order to evaluate thermal comfort degrees during the cooling season (summer). The following new indicator called Intensity of Thermal Discomfort for overheating (ITDover) [10] which is defined as the time integral of the positive difference between the current indoor temperature and the upper threshold for the comfort temperature (24°C). ...
This work aims to optimize the design of an air-conditioned multi-zone house integrated phase change materials (PCMs) considering the north Moroccan climate conditions. The objective of this optimization is to minimize the heating and cooling loads. The methodology of this optimization is based on the coupling between Energyplus® as a dynamic simulation tool and GenOpt® as an optimization tool. The results show that the obtained optimal design allows minimizing the energy consumption regarding reference house without PCM.
... This has attracted extensive attention from researchers to simulating and measuring the thermal comfort level in green building compared to conventional buildings. As a result, the range of room temperature required could be proposed [54,55]. Psychological, physiological, cultural and behavioral factors may play a role as well which attributes to adaptive thermal comfort [56][57][58][59]. ...
Construction industries have significant impacts on the economy, society and environment. To transform construction industry towards sustainability, construction enterprises' perceptions and performance on sustainability needs to be understood and evaluated, which has not be fully explored by existing studies. This paper holistically examines the Chinese construction enterprises’ attitude towards and performance on various aspects of sustainability (e.g. the economic, social and environmental aspects) in order to identify those aspects the firms perceive to be the most and least important and those aspects the firms perform best and worst on. The associations among the sustainability attitude, sustainability performance, and firm size are also explored. The findings show that quality management and customer service are perceived as the most important as well as the best-performed aspects by the firms while supporting community development is the least important and worst-performed aspect. Sustainability attitude is positively correlated with performance, and larger firms tend to have better sustainability performance than that of small ones. However, larger construction firms do not necessarily perceive sustainability more important. This study provides a useful reference for policy makers and researchers to understand how sustainability is perceived and implemented by the Chinese construction firms.
... The models for assessing visual comfort are less standardised than that of thermal comfort. An approach similar to Sicurella et al.'s method [43] is adapted in this study for evaluating the Frequency of Visual Comfort (FVC), in which illuminance values across the working plane are predicted using grid points 0.5 m apart. The upper limit for preferred daylight illuminance used is 500 lx and the lower limit is 100 lx. ...
... In order to measure the thermal discomfort due to overheating in a living space it is necessary to assess how frequently the room operative temperature exceeds a threshold value, as well as the extent by which the threshold is exceeded. On this basis, the indicator used in this work to quantify thermal discomfort is the Intensity of Thermal Discomfort (ITD), already introduced in a previous work [14]. The ITD can be defined as the time integral, over the occupancy period P, of the positive difference between the current indoor operative temperature (T op ) and the upper threshold for comfort (T lim ), see Eq. (1): ...
Buildings with large glazed surfaces may show severe thermal and visual discomfort issues, as an effect of the large incoming direct solar radiation. In order to avoid excessive solar gains and glare issues to the occupants, it is necessary to adopt suitable solutions that limit the incoming solar radiation, such as highly reflective coatings or movable shading devices. However, such devices must be accurately selected, according to the building location and to the exposure of the glazed façades, while also taking into account possible regulatory measures. This paper evaluates the effectiveness of a series of shading devices applied to an existing office building in Southern Italy. The building shows large glazed surfaces and has no overhangs, thus significant thermal discomfort is perceived in summer by the occupants. The aim is to identify those solutions that allow to improve thermal comfort while also keeping a sufficient illuminance level indoors, without disregarding the compliance with Italian regulations about the installation of shading devices and, of course, the need to keep costs on a reasonable level. The analyses are repeated for different building orientations, in order to provide general information.
... Sicurella et al. [5] propose a statistical approach for the combined evaluation of thermal and visual comfort in freerunning buildings. They reported statistical parameters suited to perform comparisons on a seasonal basis. ...
The present study is aimed at analyzing to which extent the type of window glazings affects the energy performance and the indoor comfort of buildings in Mediterranean climate. An office building located in Bari, southern Italy, was assumed as a case study due to its largely transparent envelope. Different glazings were applied to the building: a reflective window, a solar control window with low-E properties and an electrochromic window. The proposed solutions were compared with the existing windows, supposed to be ordinary clear double glazings. Thermal simulations, daylight analysis and economic evaluations were carried out to obtain an all-comprehensive view of the issue, involving energy parameters and comfort indicators. Reports pointed out that on an annual basis the main cost is entailed by cooling needs. The electrochromic window reduces the annual electricity demand for air conditioning by 17%, but its installation costs were found to be not sustainable with reference to the envelope life span. The low-E solar control window succeeds in ensuring the best thermal comfort indoors and in reducing the cost of air-conditioning by nearly 15%, as well as performing slightly better than the reflective glass in terms of electricity demand for lighting.
Biodiesel is an eco-friendly fuel derived from vegetable oils or animal fats. It is produced through the esterification of fatty acids or the transesterification of fats with short-chain alcohols. In the transesterification process, triglycerides are converted into fatty acid alkyl esters and glycerol, facilitated by an alcohol such as ethanol or methanol, and a catalyst such as an acid or alkali. The growing interest in biodiesel as a sustainable fuel option stems from concerns about depleting petroleum reserves and the negative environmental effects of emissions from traditional diesel. The sustainability and biodegradability of biodiesel are attributed to its production from renewable sources such as animal fats and vegetable oils. Most biodiesel today is produced using transesterification with methanol and an alkali catalyst, which is known for its relatively fast reaction time. Nonetheless, to avoid soap formation, the alcohol and vegetable oil used must be almost water-free and have a low concentration of free fatty acids (FFAs). This chapter explores various biofuel feedstocks, particularly edible oils; the role of different catalysts, including enzyme-based ones; and the latest technological advances in biodiesel production.
The text includes various technologies and methods that help in generating clean and renewable forms of energy. It also includes the aspects of using fuels in energy conversion media such as internal combustion engines, and comparison with existing fossil fuels. The book also focuses on green hydrogen revolution and urban heat island effect.
This book:
Covers topics such as Sustainable Biodiesel Production, Photovoltaic Devices optimization and performance enhancement, maximizing energy production, and improving the overall efficiency, reliability, and performance of solar energy systems.
Explains energy efficient green buildings, Blue-Green Infrastructure, high building energy demand, Solar Chimney, Urban Green Spaces in reducing Urban Heat Island Effect, Urban Air Quality, Building Resilience to Airborne Pathogens and challenges related to urban green infrastructure.
Discusses Carbon sequestration potential of Urban Parks, Evolution of Carbon Capture Utilization and Storage Technology, Hydrogen Production Technologies, Production and Utilization of Hydrogen as a Future Fuel for Electric Vehicles, Evaluation of Carbon Emissions from Various Vehicles.
It is primarily written for senior undergraduates, graduate students, and academic researchers in the fields of mechanical engineering, environmental engineering, energy engineering, electrical engineering, electronics and communications engineering, automotive engineering, and renewable energy.
The multi-domain comfort theory investigates human-environmental perception and comfort by accounting for people's simultaneous exposure to various stimuli from different physical domains. Multi-domain studies describe human reactions to environmental conditions, including indoor occupants' behaviour and comfort. Building simulation is essential to analyse Indoor Environmental Quality (IEQ) and energy consumption in buildings. Introducing multi-domain comfort theories in building simulation practices could improve reliability. A systematic literature review investigated the approaches adopted in multi-domain building simulation during the last decade. The simulation studies discussed herein combine two or more domains related to IEQ in buildings, indicating the state of the art, limitations, and potential trends. This review showed that multi-domain simulation comprising all the IEQ domains is still missing due to its complexity and the lack of standards for multi-domain comfort. Simulation studies mostly involved two domains - thermal and air quality or thermal and visual. The most common engines and software combinations were presented, and related interoperability issues were discussed. The most common inputs and outputs for each domain were described to identify common ground where to start building up an efficient multi-domain simulation framework. The role of the quality report was also addressed, pointing out that the current validation procedures are incipient. Advancing multi-domain simulation knowledge concurrently with understanding multi-domain comfort growth would benefit researchers and practitioners. Therefore, multi-domain simulations can become a powerful tool to guide occupant-centric building design and operation.
The prevailing impact of built environments on human well-being has long been a pivotal point of interest, particularly within the domain of human-centered design (HCD) in building engineering. While early discussions on human-oriented building engineering were primarily anchored in industrial-economic aspects, knowledge in this area remains fragmented, even as the focus has shifted to emphasize accessibility, green designs, and the rise of intelligent buildings. To provide a comprehensive overview of the knowledge domain, this study endeavors uncover the latest advancements in HCD by systematically reviewing literature from 2010 to 2023. Using bibliometric techniques and qualitative analysis, this research presents a comprehensive view of the current state of HCD in building engineering. The study identifies six predominant areas of research focus, highlighting diverse perspectives in HCD: perception of the physical environment, indoor environmental behavior, energy sustainability, communication and information exchange, user satisfaction, and indoor air quality (IAQ) health risks. This review offers invaluable insights for scholars and designers, illuminating both the current state and prospective future directions of HCD in built environments.
Most visual comfort analysis is based on glare detections in limited fixed view scenes, but sports spaces present challenges given occupants’ spatial and view directional variations in sports-related visual tasks. This paper proposes an occupant-centric approach for spatio-temporal visual comfort assessment and optimization (ST-VCAO) in daylit sports spaces by better considering the occupants’ movement behaviour. It introduces the movable view scenes (MVS) in glare simulations and further accelerates the ST-VCAO process using the GPU-based parallel simulation combining response surface methodology. The proposed approach was applied to a real case building in Harbin, China. Annual daylight and glare simulations in two tennis courts with a total of 500 MVS were performed using Perez all-weather sky model with Chinese standard weather data. Results indicate that the proposed approach could sufficiently clarify the spatial variance and temporal variation of visual comfort across all MVS, which is appropriate for sports spaces. Meanwhile, using the developed workflow, the total computational time could be saved by 27.08% (Case 1) or 71.25% (Case 2). Amongst all Pareto solutions, the optimum alternative upon the worst one observed 200% (Case 1) or 50.7% (Case 2) higher visual comfort.
There is an increasing need to improve the energy efficiency of residential buildings all around the world. Providing thermal insulation to the external walls and ceilings is a common practice for this purpose. The combined use of phase change materials (PCM) and thermal insulation in building envelopes could potentially further promote the building energy efficiency while avoiding overheating. This is evaluated in this paper by combining the use of expanded polystyrene and PCM gypsum board in the building envelope of a typical standalone Australian house. The evaluation was conducted through numerical simulation by considering the location of the house in three different Australian cities (Darwin, Alice Springs, and Sydney), which represent three different climate zones (tropical savanna, hot semi-arid, and humid subtropical). The results show that in a life cycle of 10 years, the total cost savings from the optimal combination of PCM board and insulation in Darwin, Alice Springs and Sydney are AU167.0, 162.3 and $39.7 /m 2 , respectively. Meanwhile, the energy ratings of the house are increased by 3.5, 3.8 and 4.3 stars in the three cities, respectively. The payback periods of the renovation range between 2.2 and 7.5 years, depending on the climate conditions.
Em áreas tropicais quentes, para evitar o estresse térmico, é comum a prática de que os edifícios escolares dependam do uso de sistemas de climatização mecânicos. A utilização de estratégias passivas de projeto, nessas regiões, em busca do conforto térmico com um baixo gasto energético, é de suma importância. Nesse sentido, as aberturas da edificação desempenham um importante papel, pois interferem na quantidade da radiação solar recebida e no padrão de distribuição do fluxo do ar interno. O objetivo desta pesquisa foi avaliar o desempenho térmico em uma sala de aula sob diferentes configurações de modelos de janelas e portas em Vitória, ES, e Belém, PA. A metodologia utilizou simulações de desempenho térmico e de dinâmica dos fluidos computacional para análise da intensidade de desconforto térmico e do consumo energético. Os resultados mostram que a adição do peitoril ventilado aumenta a velocidade do ar na entrada da abertura e melhora significativamente o desempenho térmico na sala de aula. O uso de brise-soleil reduz em até 50% e 13% o consumo energético no ambiente, em Belém e Vitória, respectivamente. O estudo contribui para a seleção de aberturas mais eficientes, adaptadas às condições climáticas de cada região.
A split louver consists of two sections with their slat angles to be adjusted separately for glare protection and redirection of sunlight, respectively. The upper section works in conjunction with the lower section to enhance daylight availability and uniformity throughout the year. The study aims to improve the daylighting performance of the split louver by applying a simplified parametric control, which predetermines the angle difference between adjacent slats in the upper section for a chosen solar altitude and then keeps this difference fixed during operation. The slats in the upper section can be changed parametrically using the Grasshopper to reflect daylight onto the ceiling and then illuminate the rear zone of a space. The lower section of the split louver can control the daylight in the front space area and may affect the amount of light in the back. The performance indicator in evaluating the proposed split louver design for the chosen typical days is the percentage coverage of the work plane area for the illuminance range of 150~750 lux, which was achieved up to 100% in some cases. The proposed split louver with the simplified parametric control has the potential to provide relatively consistent and distributed daylight coverage of the floor area and a glare-free environment.
There has been an increasing interest in studying energy efficiency in buildings in the recent years, as they account for a significant portion of energy consumption and greenhouse gas emissions worldwide. While most of the studies focus on the buildings' operational phase, a substantial part of buildings' energy consumption is disguised as embodied energy. It is impossible to have a zero energy building, as it is necessary to use materials to build the building, and those materials need to produce and transport energy. Life cycle analysis is the utmost efficient method to assess how a building affects the environment. Notably, the impact of buildings on the environment across their lifespans are determined by some factors, which comprise materials, design, construction, use and demolition.
The study aims to present the implementation of a life cycle approach and occupant thermal comfort during the school building's energy efficiency design. The study's principal objective focuses on the energy use and environmental impact linked to various alternatives of building envelopes in different climates. Within this context, a reference building located in three different climatic regions of Turkey is investigated. Two ranges of efficiency comprise the focal points of the study. Cost-optimal and nearly zero energy levels are defined for each city. In the hot climate, the cost-optimal scenario cannot improve the comfort conditions, whereas the nZEB scenario improves slightly in such a context. In temperate and cold climates, both strategies can improve comfort conditions. The share of embodied energy and carbon in the nZEB level can reach higher than 80 percent, whereas it is lower than 15 percent in the cost-optimal level.
The physical parameters related to indoor lighting in large industrial halls in winter and summer periods were analyzed using in situ measurements and computational methods. Here, we present part of our observations from a comprehensive research on indoor environmental quality of industrial halls with the aims of saving energy and providing a comfortable environment for the workers. The results showed that the procedures used for evaluation of residential or office buildings may not be used for industrial buildings. We also observed that the criteria for occupants’ comforts for indoor industrial buildings may differ from those of other kinds of buildings. Based on these results, an adequate attention is required while designing the industrial buildings. For this reason, appropriate evaluation methods and criteria should be created. Manufacturing halls are integral parts of industrial architecture, including buildings for light industries. Workers spend a substantial part of the time indoor; therefore, it is necessary to pay attention to design, construction, and evaluation of internal spaces of buildings and the occupants’ comfort. The focus must be given particularly to heating and cooling, moisture, and lighting microclimate. We present some observations from evaluation of internal environmental quality of industrial halls with priority on daylighting in combination with the integral lighting.
We present observations from evaluation of internal environmental quality of industrial halls with priority on daylighting in combination with the integral lighting. The physical parameters related to indoor lighting in large industrial halls in winter and summer periods were analyzed using in situ measurements and computational methods. These are part of a comprehensive research on indoor environmental quality of industrial halls with the aims of saving energy and providing a comfortable environment for the workers while improving the productivity. The results showed that the procedures used for evaluation of residential or office buildings may not be used for industrial buildings. We also observed that the criteria of occupants’ comforts for indoor industrial buildings may differ from those of other kinds of buildings. Based on these results, an adequate attention is required for designing the industrial buildings. For this reason, appropriate evaluation methods and criteria should be created. We found the measured values of daylight factor very close to the skylight component of the total illumination. The skylight component was observed on average 30% that of the measured daylight factor values. Although the daylight is not emphasized when designing the industrial buildings and its contribution is small, but it is very important for the workers psychology and physiology. The workers must feel a connection with the exterior environment; otherwise, their productivity decreases.
Com o número crescente de investimentos em edificações de interesse social, cresce também a preocupação com o conforto térmico dos usuários, uma vez que estes imóveis estão sendo replicados em diferentes regiões do país, sem a devida preocupação com a diversidade climática e com a utilização de materiais mais adequados, especialmente quando se deseja utilizar sistemas passivos para a criação de ambientes termicamente mais confortáveis. Assim, objetivou-se comparar o nível de sustentabilidade e de desempenho térmico dos materiais comumente utilizados nas vedações verticais de habitações de interesse social multifamiliares, ventiladas naturalmente em Vitória-ES. Para esta finalidade, foram realizadas simulações computacionais com o software DesignBuilder versão 3.4.0.041, adotando-se para a análise de sustentabilidade dos materiais o ISMAS, que consiste em uma ferramenta de suporte para a seleção de materiais construtivos, pautada no conceito de sustentabilidade. Os resultados apontaram que nem sempre a utilização de materiais com classificação mais alta de sustentabilidade apresentam melhores resultados quanto ao desempenho térmico, sendo necessário analisar outros parâmetros para a melhor decisão projetual.
Adaptive facades (AFs) are building envelopes that can control occupant’s visual and thermal comfort along enhancing energy savings. However, to achieve this purpose, an appropriate control strategy is needed, in which automatic control strategies facilitate effective utilization of daylight penetration in indoor spaces. In addition, these control strategies are potentially responsible for improving an occupant’s productivity and well-being by preventing discomfort risks while keeping energy in control. This paper reviews simulation-based studies which employed automatic shading control methods for balancing human comfort and energy savings. The main aim of this research is to review the existing literature and identify research gaps in controlling AFs as a pilot study for future investigations. The review basically focuses on simulation approaches towards evaluating the performance of an automatic shading control that employs either open-loop or closed-loop control algorithm. The review concludes that existing studies only investigated automatic shading controls for typical AFs such as roller shades or venetian blinds that could not deliver multi-objective control over diverse human comfort perspectives along reducing energy consumption simultaneously.
Various investigations have confirmed that pupils and teachers’ learning/teaching performance and health depend heavily on the quality and amount of daylight and indoor thermal conditions. The primary aim of using natural light in schools is to reduce energy consumption and costs, but it should also improve students’ performance. An appropriate configuration of windows improves visual and thermal comfort by reducing glare, distributing light and controlling solar energy gain.
The study focuses on the impact of different transparency ratios (WWR) and window combinations in two critical orientations (west and east) on occupants’ comfort and the energy demands of a classroom. A building was selected for a case study investigation at the design stage. One east-facing and one west-facing classroom were studied. The two classrooms were simulated with the aid of the lighting and energy simulation programs DIALux Evo 6.0, DesignBuilder 5.5 and EnergyPlus 8.9. The results indicated that a glazing ratio of 50% would reduce the requirement for artificial lighting by at least 15% as well as providing more comfortable conditions.
Lighting design in office buildings is determined by basic human needs, such as visual comfort, visual performance, and visual safety. This chapter compiles indices to evaluate the luminous quality, visual comfort, and performance in the built environment. Illuminance-based indices are used to arrive at threshold values of a luminous environment to consider as comfortable. Indices related to glare and colour rendering indicate visual performance regarding whether a physical quantity matches to a reference value. Indoor daylight performance is evaluated by assessing the indoor daylight availability and artificial lighting by field measurements, software simulation and estimating energy implication. Daylighting fundamentals, such as daylight illuminance, spatial daylight autonomy, the intensity of visual comfort, are described. The suitable colour scheme has positive effects on human emotions, work performance, and productivity. Indices indicating the colour rendering properties of a light source are the CIE colour rendering index, gamut area index, feeling of contrast index. The phenomenon of glare defines the sensation produced by luminance within the visual field that is much higher than the luminance eyes can adapt, and thereby cause annoyance and visual discomfort. Direct glare occurs due to light sources within the field of vision, whereas indirect glare may result from reflections of light sources or surfaces of excessive brightness, and veiling glare from polished, shiny or glossy surfaces, computer screens. The glare indices, such as British glare index, CIE glare index, discomfort glare index, visual comfort probability index combine the contrast between the luminance of glare source to that of background luminance, about the position of the observer.
This paper introduces a new paradigm to assess daylight in buildings called ‘useful daylight illuminance’, or UDI. The UDI paradigm preserves much of the interpretive simplicity of the conventional daylight factor approach. In contrast to daylight factors however, UDI is founded on an annual time-series of absolute values for illuminance predicted under realistic skies generated from standard meteorological datasets. Achieved UDI is defined as the annual occurrence of illuminances across the work plane where all the illuminances are within the range 100-2000 lux. These limits are based on reports of occupant preferences and behaviour in daylit offices with user-operated shading devices. The degree to which UDI is not achieved because illuminances exceed the upper limit is indicative of the potential for occupant discomfort. The relation between achieved UDI and annual energy consumption for lighting is examined.
From studies of the behaviour of children in classrooms and of workers in offices, this article suggests that we should pay more attention to the way people react positively to their thermal environment, by changes of clothing, changes of metabolic rate and modifications to the environment itself. The reactions will be constrained by social pressures, but the whole will tend towards a self-regulating system. Design might therefore concentrate on how to allow for the control mechanisms to operate rather than on trying to establish optimum indoor climates, the authors suggest.
The equation for thermal comfort for buildings in the free-running mode (Annexe A2) in European Standard EN15251 rests on the data collected in the EU project Smart Controls and Thermal Comfort (SCATs). Many of these data were from naturally ventilated office buildings which were in free-running mode outside the heating season. Using the data from these buildings a relationship between indoor comfort and outdoor climate was developed for free-running buildings. This paper describes the data and the methods of analysis used to estimate the comfort conditions in the variable environment of free-running buildings. The paper also describes how the indoor comfort conditions were related to the running mean of the outdoor temperature, and addresses the effects of air movement and humidity. The paper considers the proportions of people likely to be comfortable if the temperature differs from the neutral temperature. The differences between the adaptive comfort charts in EN15251 and ASHRAE 55-2004 are discussed.
The origin and development of the adaptive approach to thermal comfort is explained. A number of recent developments in the application of the theory are considered and the origin of the differences between adaptive thermal comfort and the ‘rational’ indices is explored. The application of the adaptive approach to thermal comfort standards is considered and recommendations made as to the best comfort temperature, the range of comfortable environments and the maximum rate of change of indoor temperature. The application of criteria of sustainability to thermal standards for buildings is also considered.
The objective of this document is to promote the use of dynamic daylight performance measures for sustainable building design. The paper initially explores the shortcomings of conventional, static daylight performance metrics which concentrate on individual sky conditions, such as the common daylight factor. It then provides a review of previously suggested dynamic daylight performance metrics, discussing the capability of these metrics to lead to superior daylighting designs and their accessibility to non-simulation experts. Several example offices are examined to demonstrate the benefit of basing design decisions on dynamic performance metrics as opposed to the daylight factor. L?objectif visé par ce document est de promouvoir l'utilisation de mesures de la performance sous éclairage naturel dynamique aux fins de la conception de bâtiments durables. Comme point de départ, ce document explore les lacunes des paramètres de mesure conventionnels de la performance sous éclairage naturel statique, lesquels visaient les conditions de ciel prises individuellement, comme le coefficient d'éclairage diurne courant. On fournit ensuite un examen des paramètres de mesure de la performance sous éclairage naturel dynamique qui avaient été auparavant suggérés, et traite de la capacité de ces paramètres de mesure à générer des conceptions d'éclairage naturel supérieures et de leur accessibilité aux non-spécialistes en matière de simulation. Plusieurs types de bureaux sont examinés comme exemples de l'avantage découlant de décisions de conception qui soient fondées sur des mesures de performance dynamiques au lieu du coefficient d'éclairage diurne. RES
This paper describes the application of a new paradigm, called useful daylight illuminance (UDI), to assess daylight in buildings. The UDI paradigm is designed to aid the interpretation of climate-based analyses of daylight illuminance levels that are founded on hourly meteorological data for a period of a full year. Unlike the conventional daylight factor approach, a climate-based analysis employs realistic, time-varying sky and sun conditions and predicts hourly levels of absolute daylight illuminance. The conventional approach produces a single number – the daylight factor as a percentage – for each evaluation point in the space. In contrast, a climate-based analysis results in an illuminance prediction for every daylight hour of the year for each point considered. The UDI paradigm offers a way to reduce the voluminous time-series data to a form that is of comparative interpretative simplicity to the daylight factor method, but which nevertheless preserves a great deal of the significant information content of the illuminance time-series. The UDI paradigm informs not only on useful levels of daylight illuminance, but also on the propensity for excessive levels of daylight that are associated with occupant discomfort and unwanted solar gain. In a conventional analysis of daylight provision and solar penetration, the two phenomena are assessed independently using methods that are idealised (daylight factor) and qualitative (shadow patterns). The UDI paradigm offers a simple methodology whereby daylight provision and levels of solar exposure are quantified using a single evaluative schema. Thus, it is also well-suited for teaching purposes. Application of the UDI paradigm is demonstrated using an analysis of design variants for a deep-plan building with a light-well. Comparison is made with the conventional daylight factor approach, the LEED daylight credit and measures of daylight autonomy.
Free-cooling is understood as a means to store outdoors coolness during the night, to supply indoors cooling during the day in summer, while free-heating is understood as a means to store the solar radiation during daytime, to supply indoors heating during the night in winter. In principle, free-cooling or free-heating can make the indoor air temperature in the comfortable region all the year if the thermophysical properties of building envelope material are in the desired range (defined as ideal thermophysical properties in this paper). Those properties are obviously related to the outdoor climate condition, internal heat source intensity, building configuration, ventilation mode etc. For a given region and a given building, the critical values of those ideal thermal physical properties can be determined through modeling and simulation. Two parameters, Iwin and Isum, are defined to describe the overcool degree in winter and the overheat degree in summer, respectively. To illustrate, the critical values of thermophysical properties of building envelope of a building located in Beijing are obtained through modeling and simulation. The simulated results are validated with experiments. The model, the methodology and the results are helpful for selection of suitable building envelope materials and for design of energy efficient buildings.
The study encompasses the validation of the dynamic, RADIANCE-based daylight simulation method DAYSIM, which uses the concept of daylight coefficients and the Perez sky model to predict the short-time-step development of indoor illuminances. Measured and simulated illuminances have been compared under 10,097 sky conditions in a full-scale test office with a double glazing and external venetian blinds. The additional planning effort for the designer compared to a conventional daylight simulation is addressed. It has been found that the treatment of direct sunlight strongly influences the accuracy of the daylight coefficient method. Three different simulation modes for the direct sunlight are investigated. The simulation results prove that indoor illuminances can be modeled with comparable accuracy for various blind settings under arbitrary sky conditions. Daylight autonomies are predicted with an accuracy below 2% points, where simulation errors stem with roughly equal parts from the raytracing and the sky model.
This paper presents a literature review of thermal comfort. Both rational and adaptive thermal comfort approaches are presented. An overview of the human body thermoregulatory system as well as the mathematical modelling of heat exchanged between human body and its environment in the situations of both awaked and sleeping people is presented.
Recently accepted revisions to ASHRAE Standard 55—thermal environmental conditions for human occupancy, include a new adaptive comfort standard (ACS) that allows warmer indoor temperatures for naturally ventilated buildings during summer and in warmer climate zones. The ACS is based on the analysis of 21,000 sets of raw data compiled from field studies in 160 buildings located on four continents in varied climatic zones. This paper summarizes this earlier adaptive comfort research, presents some of its findings for naturally ventilated buildings, and discusses the process of getting the ACS incorporated into Standard 55. We suggest ways the ACS could be used for the design, operation, or evaluation of buildings, and for research applications. We also use GIS mapping techniques to examine the energy-savings potential of the ACS on a regional scale across the US. Finally, we discuss related new directions for researchers and practitioners involved in the design of buildings and their environmental control systems.
Daylight Metric Development Using Daylight Autonomy Calculations in the Sensor Placement Optimisation Tool
- Z Roger
Z. Roger, Daylight Metric Development Using Daylight Autonomy Calculations
in the Sensor Placement Optimisation Tool, Boulder, Colorado, USA, 2006.
Thermal Environmental Condition for Human Occupancy
ASHRAE Standard 55, 2004, Thermal Environmental Condition for Human
Occupancy, Atlanta, ASHRAE Inc.
Moderate thermal environments-Determination of the PMV and PPD indices and specification of the conditions for thermal comfort
SO Standard 7730, 1994, Moderate thermal environments-Determination of
the PMV and PPD indices and specification of the conditions for thermal comfort, revised in 2005.
- R J De Dear
- G S Brager
R.J. de Dear, G.S. Brager, Thermal comfort in naturally ventilated buildings: revisions to ASHRAE Standard 55, Energy and Buildings 34 (2002)
549-561.