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This paper compares smart control models for heating supply air among five different climate conditions to discuss the effectiveness of machine learning tools in terms of control and energy efficiency. A thermostat on/off control is typically used to maintain room temperature at a desired level. Advanced computing technologies have recently been introduced to complement the conventional on/off controls to improve control efficiency in heating systems. However, these methods, which were mostly utilized to control fuel amount or fan motor speed, lacked the capability to promptly respond to various outdoor temperature conditions as climate zones requiring refined control strategies to reduce environmental impacts. This paper proposes intelligent controls of mass and temperature simultaneously for heating air supply. The Fuzzy Inference System (FIS) and Artificial Neural Network (ANN) algorithms are utilized to develop six control models, and the models are tested to evaluate both control and energy efficiency during the winter season in five climate zones (from climate zone 2 through 6; i.e., Houston, Dallas, Raleigh, Chicago, and Detroit, respectively). Results include the energy consumption, control errors, and control signals in comparison to the baseline on/off control, which confirms the fact that the ANN simultaneous controls of mass and temperature is more effective than the other controllers for control accuracy and energy savings by 71.3% and 0.3%, respectively. The effectiveness of the ANN controller can contribute to maintaining room temperature accompanying the reduction of energy consumption, which is directly related to improve human comfort and reduce environmental impacts in various climate zones. [ABSTRACT FROM AUTHOR]

The paper presents a control-oriented modeling approach for multi-zone buildings with mixed-mode cooling, based on the linear state-space representation with varying coefficient matrices. Key features are the time-variant thermal resistances, associated with the heat extraction due to airflow, calculated using an airflow network model. This approach was validated with experimental data collected in a two-zone test-building under four operation modes. A forward linear time-variant state-space (LTV-SS) model, developed based on first principles, was then used as a true representation of the building, to identify the parameters of a low-order LTV-SS gray-box model. The low-order model can predict the building thermal dynamics with sufficient accuracy with a root mean square error (RMSE) of 0.58 °C for the air and 1.08 °C for the area-weighted mean surface temperature in the south direct gain zone. Furthermore, the study develops a progressive refinement (ProRe) optimization method, following the multi-level optimization topology and branch and bound decision trimming strategy, to find sequences of binary (open/close) decisions for the motorized windows. Due to the significant improvement in computing time, the models and algorithms presented in this paper enable long-term simulation for MPC performance evaluation and implementation of predictive strategies in real controllers. [ABSTRACT FROM AUTHOR]

The aim of this paper is to evaluate summer thermal inertia in high porosity limestone old buildings. These buildings have to be retrofitted to save energy. Consequently, this paper focuses on the effects of insulation on this property. Monitoring surveys were carried out in an experimental room and in five single-family houses. In summer, thermal inertia may vary in a same building according to the localization of the room and the insulation. The analysis of monitoring data before and after insulation of the experimental room allows to highlight the improvement of thermal inertia of the room thanks to insulation: the decrement factor is divided by 10 and the time lag increases by 4 h. These results are confirmed by single-family houses measurements. The decrement factors of insulated limestone rooms are lower (0.10) than non-insulated ones (0.17) and the time lag increases by 3 h with insulation. Insulation of Tuffeau stone rooms does not cause overheating conditions in summer. These results indicate the benefit of insulation on this passive design. For these buildings, insulation reduces the temperature amplitude in summer and delays the maximum of temperature during the night. [ABSTRACT FROM AUTHOR]

Abstract: The paper focuses on the assessment of greenhouse gas emissions produced by the walls of buildings according to their lifespan. These assessments take account of the construction, maintenance and end of life. The contribution of the utilization phase must be equivalent for all technical solutions for a given usage function. In the first part of the paper, the methodology is described by (1) considering a unit area of wall (i.e. 1 square metre), (2) determining a long service life, (3) choosing technical solutions in agreement with the specifications, (4) establishing the lifespan of each technical solution according to experts, (5) finding the corresponding greenhouse gas index from an appropriate database, and finally (6) modelling the evolution of these indicators with time. Several technical solutions (concrete, brick, stone, wood, aerated concrete) are considered and lifespans range from a few years to centuries. The results of this analysis suggest and quantify the important impact of lifespan on greenhouse gas emission indicators. For example, the best technical solution for a short lifetime can be the worst on a longer duration and vice versa. In the second part, since the lifespan of a product is very difficult to determine objectively, it is considered as a variable. The numerical results presented point out the need to revisit the current life cycle tools. [Copyright &y& Elsevier]

Abstract: Assessment of pedestrian wind comfort around buildings requires the combination of wind statistics from a meteorological station, aerodynamic information and a comfort criterion. A wide range of different comfort criteria exist. In the past, several comparison studies of comfort criteria have been made. In the present paper, a different approach is pursued. The goal of this paper is threefold: (1) to provide an illustrative case study based on CFD as a framework for the comparison of different criteria; (2) to compare and evaluate the results by the different criteria as part of a complete wind comfort assessment study; and (3) to stress the importance of standardization of the wind comfort assessment procedure. The case study area is the campus of Eindhoven University of Technology. The 3D steady Reynolds-averaged Navier–Stokes (RANS) equations and the realizable k–ɛ model are used to provide part of the aerodynamic information. The CFD simulations are performed on a high-resolution grid based on grid-sensitivity analysis. Validation is conducted with on-site measurements. Part of the wind comfort assessment procedure is performed with the Dutch wind nuisance standard NEN 8100. The criteria compared in this study are the four complete criteria by Isyumov and Davenport (1975), Lawson (1978), Melbourne (1978) and NEN 8100 (2006). It is shown that the different criteria can lead to very different conclusions about the wind comfort. Because the outcome of wind comfort studies is often decisive in granting building permits, this illustrates the importance of wind comfort standardization, in particular concerning the comfort criterion. [Copyright &y& Elsevier]

Abstract: This paper is an extension to a paper previously published in the journal Building and Environment. Having determined an optimal recovery time in a controlled climatic environment, this paper aims to investigate the real impact on construction rebar workers by replicating the clinical experimentation to a series of field studies. Field studies were conducted during the summer time in Hong Kong. Nineteen rebar workers performed tasks of fixing and bending steel reinforcement bars on two building construction sites until voluntary exhaustion and were allowed to recover on site until their physiological conditions returned to the pre-work level or lower. Physiological Strain Index (PSI) was used as a yardstick to determine the rate of recovery. A total of 411 sets of meteorological and physiological data collected over fourteen working days between July and August of 2011 were collated to derive the optimal recovery time. It was found that on average a rebar worker could achieve 94% recovery in 40 min; 93% in 35 min; 92% in 30 min; 88% in 25 min; 84% in 20 min; 78% in 15 min; 68% in 10 min; and 58% in 5 min. Curve estimation results showed that recovery time is a significant variable to predict the rate of recovery (R 2 = 0.99, P < 0.05). Additional rest times should be introduced between works in extreme hot weather to enable workers to recover from heat stress. Frequency and duration of each rest time should be agreed among different stakeholders based on the cumulative recovery curve. [Copyright &y& Elsevier]

Abstract: Designing for wind driven cross ventilation is challenging due to the dynamic characteristics of wind. While numerous studies have used wind tunnels and computational fluid dynamics to study cross ventilation, few have utilized a full scale experimental approach. Thus, this paper provides measurements of wind properties, façade pressures, airflow rates through small window openings, and tracer gas concentrations for a multi-zone test building located in Austin, TX. This experimental data connects outdoor and indoor environments and demonstrates the dynamic nature of wind driven cross ventilation flow. Several interesting observations were made: (1) cross ventilation rate can be correlated to the velocity component of the approaching wind that is normal to the inlet openings; (2) obstructions that are far upwind of a building (e.g., kilometers) can have significant impacts on cross ventilation flows; (3) wind pressures on building façades are highly dynamic that a steady state assumption may not be appropriate; and (4) locations of openings that are leeward have a small impact on the overall flow rate, but significantly impact a building''s internal flow distribution. This paper provides the summary of the collected data, while the detailed dataset is available upon request. [Copyright &y& Elsevier]

Abstract: Many of a building’s systems, including heating, cooling, lighting and ventilation, work separately with each other as ‘isolated islands’. While separate systems do not typically work optimally in terms of total performance, integrated control has the potential to improve energy efficiency, occupant comfort and satisfaction and cost efficiency. Preceding studies also have stressed the needs for individual control and usability in order to achieve occupant satisfaction. First, this paper provides a solution concept for integrated control for a space and describes various inputs and outputs of integrated control. As an example, an optimisation strategy for discontinuous use of buildings is presented. The optimisation strategy was first simulated and then implemented in a real building. Second, modular user interfaces for adjusting environmental conditions are provided in the paper. The user interfaces modules are based on user research and usability testing to avoid the usability problems that have been identified in many studies regarding user control of indoor environments. The modules can be utilised in different user interface configurations for different types of spaces in a building. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes and evaluates an integrated workflow that simultaneously uses ventilation, thermal, and luminous autonomy for the assessment of passive design strategies, introducing a potential way to integrate these three metrics in the design process. We developed a new metric, ventilation autonomy, and assessed the advantages and limitations of applying the three autonomy metrics with building performance simulations in two climates. We developed a novel visualization to display the hourly and yearly environmental autonomy values. The results show that when we consider the three metrics together, designers may have contradicting design directions if trying to both mitigate the solar radiation and to utilize natural ventilation. The visualizations that categorize nine combinations of thermal and visual comfort along with ventilation autonomy are effective in showing the trade-offs among ventilation, thermal, and visual performance. Graphical abstract Image 1 Highlights • We develop, define and assess a new metric, ventilation autonomy. • We propose an integrated workflow for luminous, thermal, and ventilation autonomy. • We evaluate the advantages and limitations with building performance simulations. • Major trade-offs between mitigating solar radiation and using natural ventilation. [ABSTRACT FROM AUTHOR]

Abstract Traditionally, the tracer method has been used to distinguish the supply air and room air in buildings by labeling the target air with a tracer. However, due to difference in the physical properties of the target air and the tracer, use of the tracer method inevitably produces tracer error. Furthermore, due to the lack of an exact comparative reference, it is difficult to determine which tracer is the best to represent the target air distribution. In this study, a method (i.e. self-label method) which can distinguish supply air from ambient air without tracer in numerical simulations has been developed. In this paper, the principle, governing equations, accuracy, and applications of the self-label method are presented. Further, due to its simple and typical mixing characteristics of supply air and ambient air, a jet has been used to validate the numerical model by comparing the numerical results with the classical theoretical and experimental results in the earlier studies. The validity of the self-label method has been verified by comparing the flow rate and the velocity field of the jet with those by the single air approach. The tracer gas error has been compared with the exact reference obtained by self-label method. The results show that the tracer gas error increases with increasing tracer concentration or decreasing air velocity under isothermal conditions. Finally, the dynamic mechanism of the tracer gas error has been analyzed. It shows that an additional concentration buoyancy force can occur, which can cause tracer gas error under isothermal conditions. Highlights • Self-label method to distinguish supply air from room air in CFD simulations. • Principle, governing equations, and accuracy of self-label method are presented. • Potential applications and engineering meaning of self-label method are proposed. • Comparison of the tracer gas error with the exact reference by self-label method. • Analysis of dynamic mechanism of tracer gas error. [ABSTRACT FROM AUTHOR]

Abstract A data driven framework for the energy and comfort management in large buildings with multiple zones and dynamic occupancy patterns is presented in this paper. For such cases, precise heat conduction models derived using the classical thermal physics laws will be cumbersome. The approach uses the historical data to develop a multi-variable model through Structural Equation Modeling (SEM) so as to identify the relative dominance of the direct and indirect effects of thermal coupling among the neighboring zones, occupancy and the external climate variations on the thermal behavior of the building zones. Based on the information gathered from the SEM, we can predict the return temperatures more accurately, which in turn is employed to incorporate a flexible control strategy for the HVAC system. A controller fed with the temperature error and occupancy error, between the predicted and measured values, regulates the supply air fan speed via VFD motor and outside air damper valve openings. This has resulted in the energy savings while maintaining the occupant thermal comfort at the reasonable levels. The framework proposed has been evaluated using real data collected from an HVAC system of a big airport terminal building. The results show that the accuracy of prediction is relatively higher than with other regression techniques; and that the HVAC system is energy efficient and can ensure occupant comfort on real-time basis in large buildings. [ABSTRACT FROM AUTHOR]

Abstract Outdoor spaces are important to sustainable cities because they establish a common identity for social life by improving quality of urban living. The relation between outdoor spaces and building groups, competency, use period, and interaction of micro-climatic factors are needed to be investigated from a holistic approach. Unfortunately, the limited and narrow scoped POE studies on outdoor spaces make an overall assessment without causality relation. Other existing studies in outdoor spaces are mostly grouped under the headings such as; user satisfaction, space syntax and behavioral mapping, and biometeorological assessments. The intention of this paper is to introduce a new post-occupancy evaluation (POE) method integrates these studies focusing on various problems in outdoor spaces using spatio-temporal mapping. The comprehensive methodology applied in this research attempted to overcome some of the shortcomings of related studies by conducting a longitudinal study (during a year, as opposed to a few days) and also by objectively analyzing the associations of user behavior and physical attributes as well as the configurational properties of the campus layout. With this method, outdoor spaces can be evaluated in the context of the interaction between the physical environment and its users' behavior and activities, level of satisfaction and perceptions of comfort. The method has been applied on a suburban university campus in İstanbul, Turkey. The main courtyard of the campus has been subjected for map creation and result discussions. Highlights • Outdoor spaces create a common identity for social life enabling communication and socialization. • There is a paucity of research on campus outdoor spaces. • Proposal of a new POE approach for outdoor spaces. • The POE method integrates different studies on various problems in outdoor spaces. • The POE method will complete the missing link in outdoor space design process. [ABSTRACT FROM AUTHOR]

Abstract Implementing energy saving measures (ESMs) in buildings is a critical part of the global de-carbonization process. To private building owners, the cost-effectiveness of ESMs is a major concern. To public policy makers, maximizing carbon reduction within budgets is a common goal. As such, a plethora of studies have been pursued to evaluate the economic or environmental effectiveness of ESMs; however, the reliability of their results are often uncertain due to the dearth of real data. This paper reports a case study on evaluating the retrofit adopted for the air-conditioning (AC) system of a commercial building in Hong Kong. Using longitudinal energy and cost data of the AC system, the economic performance of the retrofit was evaluated by analyzing its net present value and return on investment, and an indicator known as 'carbon reduction efficiency' was introduced to assess the environmental-cum-economic performance of the retrofit. Besides the development of a scaling factor that accounts for the climatic influence on AC energy use, the effect of equipment degradation on the long-term environmental performance of the retrofit was revealed. Providing empirical evidence of economic or environmental effectiveness of ESMs, this study illustrates a rigorous, pragmatic approach to evaluating retrofit projects in real-world buildings. Highlights • Used real data to evaluate the economic performance of building energy retrofits. • Assessed environmental-cum-economic performance by carbon reduction efficiency. • Developed a scaling factor that accounts for climatic influence on energy use. • Revealed the effect of equipment degradation on the energy performance of retrofits. [ABSTRACT FROM AUTHOR]

The surface-averaged forced Convective Heat Transfer Coefficient (CHTC avg ) at a windward building facade is influenced by the complex interaction between a wide range of parameters. Existing CHTC expressions, however, consider the impact of these parameters either incompletely or not at all. Earlier studies have shown that this shortcoming can lead to significant errors in Building Energy Simulations. In this paper, therefore, the combined impacts of wind speed (U 10 ), building height (H) and width (W), and wind direction (θ) on the CHTC avg for the windward facade of buildings are systematically investigated. High-resolution CFD simulations of wind flow and forced convective heat transfer, validated with wind-tunnel measurements, are performed for 64 building geometries (10 m ≤ H and W ≤ 80 m), 8 wind directions (0° ≤ θ ≤ 78.75°) and 4 reference wind speeds (1 m/s ≤ U 10  ≤ 4 m/s). The 3D steady RANS equations with the realizable k-ε turbulence model and the low-Re number Wolfshtein model are used. The results show that for a given building geometry and U 10 , the CHTC avg decreases as θ increases from 0° to 78.75°. The maximum reduction of about 42% occurs for the building with H = 8W = 80 m. In addition, for a given θ and U 10 , by increasing H, the CHTC avg increases, while increasing W has the opposite impact on the CHTC avg . Finally, a new generalized CHTC expression is presented as a function of U 10 , H, W and θ, and its accuracy is confirmed by detailed in-sample and out-of-sample evaluations. [ABSTRACT FROM AUTHOR]

Human individual differences widely and markedly affect thermal comfort and should be carefully considered in the design and operation of the built environment. This paper aims to list and examine the magnitude and significance of individual difference in the preferred/neutral/comfort temperature through reviewing previous climate chamber and field studies. Causal factors for individual differences are investigated, including sex, age and etc. There is no clear and consistent conclusions as to the significance and size of inter-group differences in thermal comfort (between females and males, or the young and the old). To address the issue of individual difference, a paradigm shift from centralized to personalized air condition is on the way with the following three steps: first, collecting individual physiological and psychological response; second, predict individual comfort with machine learning algorithms; and third, accommodating individual difference with Personalized Comfort Systems. [ABSTRACT FROM AUTHOR]

Extremely hot environments are common in industrial buildings, which impose thermal risks on the homeostasis of the human body. Thermal protective clothing (TPC) also places physical and thermal burdens on workers. In order to ensure workers' health and work efficiency, a continuous graphical index is developed in this paper to assess heat strain in extremely hot environments, avoiding hard measurements of physiological parameters. To study human interaction with the indoor thermal environment, a climate chamber was constructed to simulate extremely hot environments. Twenty male sports majors were asked to perform intermittent treadmill exercise while wearing TPC. During the human trials, rectal temperature, heart rate, hand grip strength, ratings of perceived exertion, and ratings of thermal sensation were measured. The results of a two-way repeated analysis of variance revealed that the perceptual strain index (PeSI) can reflect influences of different work intensities and dry bulb temperatures on human heat tolerance. The results of a regression analysis revealed a strong correlation between the physiological strain index (PSI) and the PeSI. In addition, the results also revealed a strong correlation between the PSI and work efficiency. By fitting the continuous function, the proposed index defined the comfort limit, efficiency limit, and safety limit for manual labourers wearing TPC. Therefore, the proposed index derived from the findings can be used to assess heat strain and work efficiency of workers in extremely hot environments. [ABSTRACT FROM AUTHOR]

People spend most of their lives in buildings and unavoidably perceive the sound in their surroundings. The understanding of the human perceptual dimensions of sound is important for obtaining the occupant-oriented decision-making in future building designs. This paper presented a systematic review of the studies analyzing the human perceptual dimensions of sound. Studies that used of principal component analysis (PCA) or factor analysis (FA) for the semantic differential method (SDM) applications of the subjective measurements of the human perceptions of sound were identified in the study selection process and included in the quantitative analysis. Forty-five eligible studies covered a wide range of sounds in the general indoor environment, including machines, building facilities, human voices, human activities, transportations, and the urban environment. The meta-analysis of the factor analysis integrated the data from the 39 individual studies and generated the evidence-based results of the review. Three major perceptual dimensions of sound were found to be ”Evaluation,” ”Potency,” and ”Activity” which referred to the human general judgment, the sensitivity to the magnitude, and the sensation of the temporal and spectral compositions of the perceived sound respectively. It implied that not only the energy level but also the energy distribution of the stimulations in the environment affects our perceptions. The review also provided insights into the selection of the suitable perceptions, the suggestions on the SDM applications, and the acoustics index development for the quantification of the psychological impacts of sound on the occupants in the indoor and outdoor environment. This research provides directions for future psychoacoustics studies to analyze the correlations between the objective stimulations and the human perceptions. [ABSTRACT FROM AUTHOR]

In the last decade, Mexico has been prominent among the Upper-middle-income countries (UMC) due to the application of its Funding Program for Housing Solutions (FPHS) in dealing with social housing. This paper shows the results of the evaluations carried out, through the internationally recognized Building Sustainability Rating Systems (BSRS), on different housing units built under this program. It was necessary to carry out a normalization criteria process (NCP) due to the particular characteristics of each BSRS and the complexity they presented in carrying out a comparative analysis. Case studies indicate that housing developed by the FPHS obtained low qualifications according to internationally focused BSRS, with significant deficiencies concerning materials, energy efficiency, indoor environmental quality, and management. However, this study provides indicators of its possible integration in the social housing of countries with characteristics analogous to those of Mexico. Among all indicators, that those referring to the urban environment are capable of being integrated into the social housing. Among the findings, some aspects of the FPHS evaluation process impede the integration of sustainable characteristics in Mexican social housing. On the other hand, the FPHS evaluation model, which gives priority to urban environment aspects above all else, may represent a new paradigm towards the achievement of the sustainable social housing (SSH). [ABSTRACT FROM AUTHOR]

This paper presents an analysis conducted upon custom temperature setpoint change request data collected from four large office buildings. In three of these buildings, the setpoint changes were executed upon hot and cold complaints; and in the fourth building, the occupants could adjust their setpoints through their thermostats. Using concurrent indoor and outdoor temperature records, multivariate logistic regression models predicting the frequency of custom setpoint change requests were developed. The indoor temperatures that minimize the frequency of thermal complaints or thermostat overrides were determined with these models. It is argued that these temperatures can be used to select building specific default seasonal temperature setpoints. The results indicate that the majority of the setpoint change requests were either to increase the default 22 °C temperature setpoints during the cooling season or to decrease them during the heating season. Custom setpoint change requests were registered 24 times more frequently when occupants were permitted to make temporary thermostat overrides. It was also identified that the operators tend to make greater setpoint changes upon hot and cold complaints than the occupants make through their thermostat overrides. [ABSTRACT FROM AUTHOR]

The occupants are one of the major factors influencing indoor environment and building energy consumption. As for airport terminal buildings, the passenger flow distinguishes them from other common public buildings. Thus, the relevant researches are of significant necessity, especially in the recent airport construction boom in China. This paper describes the field investigations of passenger flow in each public area (i.e., check-in hall, departure hall, arrival hall, baggage claim area, arrival passage and transfer hall) of a Chinese hub airport terminal in typical three months of three different seasons. The passengers' dwell time and the total occupant number are two mainly surveyed parameters. The results show large differences in the characteristics of passenger flow between various areas in the terminal building. Furthermore, based on the surveyed dwell time distributions of passengers and the real-time data of passenger flow intensities, the total number of occupants in the check-in hall and the departure hall can be estimated separately. This prediction model will be useful both in design and operation processes of an airport terminal. [ABSTRACT FROM AUTHOR]

This research aims to optimize a multi-zone Air Handling Unit's (AHU) energy consumption by using a Non-linear Model Predictive Control (NMPC) approach. In this paper, Genetic Algorithm (GA) and Non-linear autoregressive network with exogenous inputs (NARX) have been utilized to design NMPC for a multi-zone AHU. The NMPC problem could be divided into two main sections: internal model and the optimizer. NARX serves as the controller's internal model to predict the building's thermal dynamics. GA is then used to solve the NMPC problem and find the optimal value of the control signals at each time step. The proposed NMPC jointly minimizes energy consumption of the AHU and the deviation from the set-point temperature. Finally, the designed controller was implemented and applied to the mentioned AHU. Also, a data acquisition system has been fabricated to secure training and test data for NARX. Utilizing NARX for modeling system's dynamics resulted in a highly accurate model with an accuracy of 97.71%. The empirical results of the proposed NMPC showed significant reduction in gas and electricity consumption of the AHU. NMPC yielded a 55.1% and 43.7% reduction in electricity and gas consumption of the AHU respectively. [ABSTRACT FROM AUTHOR]

Life Cycle Assessment (LCA) is considered as the most suitable way to assess the environmental impact of buildings. Due to its extensiveness and complexity, but also due to a lack of knowledge amongst architects, the LCA methodology is currently most often applied as a post-design evaluation and not used to support or optimize design decisions during early design stages. Therefore, this paper looks at possible solutions to apply LCA, including operational energy demand simulation, in early design from two different perspectives: design-oriented user requirements, derived from literature, a survey, interviews and a focus group with architects, and LCA simplification strategies based on a literature review. Both perspectives are discussed and merged into an evaluation framework that can be used to check the suitability of LCA-based environmental impact assessment (EIA) tools for use by architects during early design stages, but also to develop new design-supportive LCA-based EIA tools. In turn, this can contribute to an increased uptake of these tools in building practice. [ABSTRACT FROM AUTHOR]

This research investigates sustainable building design from a new perspective – green design in relation to green building rating systems. We examine the potential influence of Green Star (GS) in Australia on the design of a project and compare this with the Leadership in Energy and Environmental Design (LEED) in America and Assessment Standard for Green Buildings (ASGB) in China. The comparison is conducted using a typical case study of a GS Six Stars certified example, the Melbourne School of Design building. A critical review concludes that LEED and ASGB are design-guide schemes while GS is a performance-based rating system and this affects the project outcome. We note that LEED is oriented to energy efficiency while GS and ASGB holistically consider energy and indoor environment quality. GS, additionally, emphasizes project process management. Potential LEED and ASGB certification levels for the case are calculated; possible changes to the design are indicated to achieve the highest LEED and ASGB levels. The predicted results demonstrate the influence of different environmental concerns and assessment approaches of the three on the green design and the performance of buildings themselves. Based on this finding, the paper argues that a performance-based rating system (e.g. GS) is more beneficial to the practice of designing green, compared with other measure-based systems. [ABSTRACT FROM AUTHOR]

Buildings generate nearly 30% of global carbon emissions, primarily due to the need to heat or cool them to meet acceptable indoor temperatures. In the last 20 years, the empirically derived adaptive model of thermal comfort has emerged as a powerful alternative to fixed set-point driven design. However, current adaptive standards offer a simple linear relationship between the outdoor temperature and the indoor comfort temperature, assumed to sufficiently explain the effect of all other variables, e.g. relative humidity (RH) and air velocity. The lack of a signal for RH is particularly surprising given its well-known impact on comfort. Attempts in the literature to either explain the lack of such a signal or demonstrate its existence, remain scattered, unsubstantiated and localised. In this paper we demonstrate, for the first time, that a humidity signal exists in adaptive thermal comfort using global data to form two separate lines of evidence: a meta-analysis of summary data from 63 field studies and detailed field data from 39 naturally ventilated buildings over 8 climate types. We implicate method selection in previous work as the likely cause of failure to detect this signal, by demonstrating that our chosen method has a 56% lower error rate. We derive a new designer-friendly RH-inclusive adaptive model that significantly extends the range of acceptable indoor conditions for designing low-energy naturally-conditioned buildings all over the world. This is demonstrated through parametric simulations in 13 global locations, which reveal that the current model overestimates overheating by 30% compared to the new one. [ABSTRACT FROM AUTHOR]

This paper proposes a methodology for monitoring and data analysis in buildings, leading the user in the design and implementation of smart environments able to collect information on spaces and the comfort perceived by their inhabitants. A systematic descriptive framework is defined to identify the most convenient strategies for monitoring and data interpretation, driven by the constraints and goals set by how data will be exploited. A wide body of field works has been analyzed and put in relation to the methodology, highlighting the difficulty to extract general guidelines with respect to the same goal and to reveal use case specificity, preventing the possibility to learn from previous solutions. We claim the need to overcome the specific features of each case study to elicit general knowledge, and thus the quest for a unified framework, useful in different scenarios. [ABSTRACT FROM AUTHOR]

The environmental and economic impacts of alternative façade systems have been widely investigated in previous studies. However, sustainable design requires reconciliation between economic, environmental and social impacts; the three pillars of a sustainable system, and selection of façade only based on environmental impacts may not always provide a sustainable solution. Through a case study, this paper presents a systematic methodology for selection of the façade system for a building by accounting the social, economic, and environmental impacts of the decision. A comprehensive list of sustainability criteria for selection of façade systems is presented and discussed in detail. The selected sustainability criteria are then applied to identify the most sustainable facade system, among five different alternatives including double brickwork, aluminium composite panel, ceramic cladding, Autoclaved Aerated Concrete (AAC) panels and concrete blocks, to replace the existing worn façade of an actual building. Delphi technique, a method of eliciting and refining group judgments, is used to identify applicable sustainability criteria and their relative pair-wise importance scores, while AHP is used to identify the global relative importance weights for different sustainability criteria and rank different alternative façade systems. [ABSTRACT FROM AUTHOR]

This paper presents a numerical analysis of the effect of fine particle pollution on the natural ventilation potential of office buildings in nine European cities. Several years of measured weather and PM2.5 concentration data were used to perform statistical and dynamic thermal and airflow simulation analysis. The statistical analysis confirmed that most PM2.5 is locally generated. Higher PM2.5 levels occur in the morning, when wind speeds are low and commuter traffic is high. Unfortunately, in most of the analyzed cities, most hours when daytime weekday outdoor temperatures are mild have elevated PM2.5 levels (up to 95% of the hours). The simulation analysis shows that a hybrid NV system can reduce the electricity consumption of a well-designed office building by up to 60%, in comparison to an office using only mechanical HVAC equipped with a high-efficiency particle filter. Unfortunately, in this hybrid approach, elevated outdoor PM2.5 levels penetrate into the working environment and increase occupant cumulative exposure by 1.9–4.2 times (compared to the standard HVAC system). Limiting the use of NV to moments of low outdoor PM2.5 concentrations limits the exposure increase to 1.3 to 2.4 times but reduces the maximum energy savings to 40%. The last part of this study analyses the tradeoff between energy savings and increased exposure, revealing that in Antwerp, Lisbon and Paris most NV-related energy savings occur in moments of low outdoor PM2.5 levels, thereby limiting the increased exposure effects that occur when unfiltered NV air enters into the working environment. [ABSTRACT FROM AUTHOR]

The advanced air distribution methods such as displacement ventilation and personalized ventilation attempt to seek a balance between better indoor air environment and energy efficiency. However, multiple demand scenarios including variable locations of occupants and indoor sources may exist in daily operation of the ventilation system. Most of existing airflow patterns are single mode and cannot always be efficient when responding to changeable scenarios. In this paper, a novel ventilation strategy, i.e., multi-mode ventilation (MMV), is proposed to address multiple scenarios. MMV is designed by the combination of several single airflow patterns and aims to utilize the individual advantages of each airflow pattern in controlling specific scenarios. The energy saving potential of MMV is demonstrated by numerical studies of a meeting room. An indexed local cooling load (LCL) is adopted to evaluate the performance of airflow patterns. As a key parameter in LCL calculation, the required supply temperature to maintain the set temperature at the target zone is determined by computational fluid dynamics (CFD) method. The results show that each single airflow pattern can only be efficient for part of 8 scenarios. MMV performs better by combining single airflow patterns 1 and 2 regardless of the changes of the location and magnitude of the occupied zone as well as the location of the heat source. MMV achieves a reduction rate of up to 56.8% in cooling load compared with airflow pattern 4. MMV may provide a reference for real projects in controlling temperature, humidity and contaminant concentration under changeable scenarios. [ABSTRACT FROM AUTHOR]

Buildings could be transformed into interactive living spaces that communicate with their occupants and influence the way occupants behave in buildings. This paper focuses on investigating the effectiveness of incorporating social influence methods in the design of energy saving messages. Specifically, we examined the use of two classic compliance-gaining strategies that proved to have great influence on behavior in social psychology: foot-in-the-door and reciprocity and compared them to direct request. One hundred fifty participants were randomly assigned to one of the three experimental groups. Participants in three groups received text based messages that included the same simple energy saving tip. The only difference between the messages was the social influence methods used in framing the messages. Through the use of an immersive virtual environment, we observed the participants' compliance with the messages. Our analysis showed that reciprocity received significantly higher rates of compliance both in the virtual and physical environments. In addition, significant effects were found between the participants' personality traits and their compliance with the messages. We also found carryover effects between the behavior in the virtual part of the experiment and subsequent responses in the physical environment, suggesting participants acted in the same way in both environments. [ABSTRACT FROM AUTHOR]

The Leadership in Energy and Environmental Design (LEED) is considered as one of the most successful green building rating systems. As one of the most successful versions, LEED v2.2 was launched in 2005 and has accredited more than 5000 projects globally. This paper reviews the use of LEED v2.2 and investigates the allocation pattern of LEED points by critically analysing a database of all LEED v2.2 certified projects until its certification sunset date. The results show that innovation-related points are the easiest to obtain, while energy-related and material-related points are the most difficult to obtain. Different regions, either across the world or in the US, perform differently on selected LEED v2.2 credits, especially on spatially specific credits, such as brownfield redevelopment and green power. Varied credit achievement patterns are also identified on yearly, cross-certification and cross-section levels. The study offers a useful reference for project developers to understand the LEED rating systems and for regulatory bodies to improve the rating system. [ABSTRACT FROM AUTHOR]

Natural and bio-based construction materials represent a promising solution for optimizing buildings' environmental sustainability. In this view, the paper presents the multipurpose experimental thermo-acoustic characterization of common reed-based building panels. Different geometries, densities, humidity rates and stalk shapes were considered and tested by means of hot-plate, hot-box and impedance tube in-lab experimental benches. The thermal analysis showed that the geometry scarcely affects the thermal conductivity, which is around 0.05 W/mK and, therefore, comparable to other materials already commercialized for the same scope. On the other hand, the acoustic behavior is strongly affected by the stalk configuration, e.g. perpendicular, parallel or combined orientation with respect to the incident wave. In particular, the longitudinal stalk layout showed a significant sound ​absorption performance. The exhaustive experimental original characterization of such by-product, therefore, showed a very promising overall thermo-acoustic behavior. At the same time, for optimizing the panel field performance, the acoustic requirements should represent the panel design drivers, given the high sensitivity of the panel layout characteristics affecting the acoustic performance. [ABSTRACT FROM AUTHOR]

Both the construction and use of buildings cause significant environmental pressures. The greenhouse gas (GHG) emissions imposed by buildings have been studied rather extensively, but less is known about other impacts. Still, climate change is only one harmful impact driven by buildings. Furthermore, no studies exist about how the other impacts are correlated with GHG emissions in the building context, and thus to what extent GHGs could be utilized as a more general environmental performance indicator. This paper fills these gaps by presenting a life cycle assessment of the pre-use phase of a modern concrete-element residential building with a very comprehensive life cycle inventory (LCI). The focus of the study is on the comparison of the accumulation of different environmental impacts relative to GHGs. The accumulation is analyzed from two perspectives common to building LCAs: building systems and different construction materials. The ReCiPe midpoint assessment method is utilized to reach wide impact category coverage. The study shows how GHGs act as a relatively good indicator for eight impact categories, but not for the others. The study also depicts that a very high coverage in the LCI must be reached to capture the majority of the different impacts. Many materials and building systems are considered non-relevant and are often excluded from building LCAs, which are in fact of great importance in many impact categories. [ABSTRACT FROM AUTHOR]

In this paper we explore the notion of comfort expectations and ask the question whether they change as a result of long-term exposure to mild indoor climates. A comparative questionnaire survey was conducted in China where indoor thermal environments during winter in the northern region (with pervasive district heating) are much warmer than in the southern region (without district heating). Four subject groups were surveyed 1) subjects who had lived in the northern region of china with district heating all their life, 2) subjects who grew up in the southern region without district heating but as adults had moved to the north where district heating was pervasive, 3) subjects who had lived in the southern region of china without district heating all their life, and 4) subjects who grew up in the northern region with district heating but as adults had moved to the north where district heating was non-existent. Subjects who had lived their entire lives in the northern region with neutral-to-warm indoor climates had quite similar comfort perceptions and expressed the same levels of thermal acceptability as did those subjects whose life had been spent in the southern region, devoid of any district heating. Statistical analysis of the two sub-groups who migrated, north or south, indicated that it building occupants get accustomed to the thermally neutral lifestyle more easily and faster than do their counterparts who went from thermally neutral indoor climates of the north to the cold and uncomfortable indoor climates of the southern regions of China. [ABSTRACT FROM AUTHOR]

The occupant behavior (use of heating, use of air conditioning, use of light, opening of windows, adjustment of curtains and blinds, etc.) in a building is usually closely related to the environmental conditions. This paper presents a novel general mathematical formula for describing the relationships between such behavior and the environmental conditions based on a memoryless hypothesis and psychophysical function (Stevens' power law). Compared to existing formulas, the proposed formula is simple and harmonizes both the threshold and stochastic characteristics of an occupant's response to environmental stimuli. Preliminary test showed that the formula has good applicability and reliability. The proposed formula can serve as a basic reference for detailed modeling of an occupant's heating, air conditioning, lighting, window opening, and shading adjustment behavior in the future. [ABSTRACT FROM AUTHOR]

Hemp–lime is a potentially useful building material with relatively low embodied energy and moderate-to-good thermal performance, coupled with good moisture buffering capacity. However, some uncertainty remains with regards to its in-situ thermal performance and the capability of building energy simulation tools to accurately predict envelope performance and subsequent energy demand of buildings constructed of such vapour-active materials. In this paper we investigate the hygrothermal performance of buildings with walls constructed from hemp–lime. Component-level moisture buffering simulation employing the EnergyPlus simulation tool is found to be within 18% of Wufi Pro analysis and laboratory measurements. The coarseness of component discretization is shown to effect moisture buffering leading to the observation that finer discretization should be employed to improve EnergyPlus HAMT model accuracy. Whole building simulation of the BESTEST building with hemp–lime components indicates that moisture transport inclusion has a large influence on zone relative humidity but little influence on overall heating and cooling demand. A simple effective-capacitance model is able to represent humidity buffering but is less good at representing the response to sudden moisture loading. An additional resistance parameter is added to the model and an IES-ve simulation using this approach is shown to give a close match to the full hygric simulation. [ABSTRACT FROM AUTHOR]

Abstract: In this paper cross natural ventilation due to buoyancy assisted by wind is investigated with computational and laboratory simulation. The impact of the outlet's opening position is investigated, forming cross ventilation of variable distance h – namely, the vertical distance between midpoints of leeward and windward opening –, for three initial Froude numbers: (i) Fr0 = 1.15, (ii) Fr0 = 2.79, (iii) Fr0 = 4.85. For the computational simulation a fluid dynamic software is used and the problem is solved by solving the 3D unsteady Reynolds Averaged Navier Stokes (RANS) equations in conjunction with the energy equation and the turbulence model RNG k-ε. The laboratory simulation took place in an open channel and the experimental model represents a building form of orthogonal shape. The interior of the experimental model is filled with solution of ethanol at conditions of normalized gravity, but also with salted water at conditions of inversed gravity. The time taken for the indoor space to empty is calculated numerically and experimentally. Based on Froude number dynamic similarity, the experimental and computational results are characterized by good agreement and the functional process of natural ventilation is being explicated. In addition, the suggestion of using ethanol solution for the density difference between interior and exterior fluid in laboratory simulation of natural ventilation is verified successfully, as the results with use of ethanol solution are in good agreement with those using salted water. [Copyright &y& Elsevier]

Abstract: The thermal resistance (R-value) of an enclosed airspace depends on the emissivity of all surfaces that bound the airspace, the size and orientation of the airspace, the direction of heat transfer through the airspace, and the respective temperatures of all surfaces that define the airspace. A table is provided in the 2009 ASHRAE Handbook of Fundamentals (Chapter 26) that contains the R-values of enclosed airspaces. The ASHRAE table is extensively used by modellers, architects and building designers in the design for thermal resistance of building enclosures. This table provides R-values for enclosed airspaces for different values of airspace thickness, effective emittance, mean airspace temperature, and temperature differences across the airspace. The effect of the airspace aspect ratio (length/thickness) on the R-value is not accounted for in the ASHRAE table. However, in previous studies, it was shown that the aspect ratio of the airspace can affect its R-value. In this paper, previous studies undertaken by the author that focused on determining the R-value for vertical enclosed airspaces and horizontal enclosed airspaces with downward heat flow are extended to investigate the effect of the aspect ratio on the R-value of horizontal enclosed airspaces under an upward heat flow condition for different airspace thicknesses and having a wide range of values for effective emittance, mean temperature, and temperature differences across the horizontal airspaces. The R-values predicted from numerical simulation are compared with those provided in the ASHRAE table. Considerations were also given to investigate the potential increase in the R-values of enclosed airspaces when a thin sheet is placed horizontally in the middle of the airspace and whose surfaces have different values of emissivity. Thereafter, practical correlations are developed for determining the R-values of horizontal enclosed airspaces for future use by modellers, architects and building designers. The simplicity of these correlations for horizontal airspaces with upward heat flow along with those that were previously developed for vertical airspaces and horizontal airspaces with downward heat flow suggests that these correlations could be included in the ASHRAE Handbook of Fundamentals. [Copyright &y& Elsevier]

Abstract: In this paper, we propose a method for assessing renovation packages drawn up with the goal of increasing energy efficiency. The method includes calculation of bought energy demand, life-cycle cost (LCC) analysis and assessment of the building according to the Swedish environmental rating tool Miljöbyggnad (MB). In this way the methodology assesses economic, indoor environmental quality (IEQ) and specifically environmental aspects associated with energy demand of such packages from a sustainability point-of-view. Through MB, energy efficiency packages are placed in context with other necessary measures required to improve environmental performance in buildings, providing a consistent and systematic basis other than simply financial performance by which to compare capital improvements. The method is further explained and analyzed by applying it in three case studies. In each case study a multi-family building representing a typologically significant class in the Swedish building stock is considered, and for each building a base case and two renovation packages with higher initial investment requirement and higher energy efficiency are defined. It is shown that higher efficiency packages can impact IEQ indicators both positively and negatively and that packages reducing energy demand by approx. 50% have somewhat higher LCC. Identified positive IEQ impacts point to added value for packages that may not otherwise be communicated, while negative impacts identify areas where packages need to be improved, or where MB indicators may be referred to as specifications in procurement procedures. [Copyright &y& Elsevier]

Abstract: Post Fukushima disaster, the energy consumption perspective in Japan has changed. It initiated unprecedented exercises towards energy saving and produced interesting results. These included the ‘setsuden (energy saving)’ campaigns, which promoted the minimum indoor temperature setting of 28 °C in summer. However, there is no scientific basis for this recommendation. Japan does not have adaptive comfort standards and the ASHRAE standard-55 does not include the data from the land of the rising sun. In this context, we conducted a thermal comfort field study in four office buildings in Tokyo for three months in summer 2012. We measured all the four environmental and the two personal variables. Through a paper based field survey, we interviewed 435 occupants who returned 2402 questionnaires. The occupants'' comfort temperature was found to be 27.2 °C. Thermal acceptability was very high at 89% even when 26% of the environments were outside the three central categories of the thermal sensation scale. PMV always significantly overestimated the sensation owing to a wide range of adaptations by the subjects. The indoor air speeds were low, indicating a need for ceiling fans. In 50% of the environments the indoor temperature was more than the 28 °C limit. As the buildings were designed for AC mode, running them in NV mode posed challenges. This study calls for elaborate field studies in offices in Japan for the development of custom made adaptive comfort standards. [Copyright &y& Elsevier]

Abstract: As the main regulation tool of indoor thermal environment in warm seasons, air-conditioners are used to keep a cool environment. However, this causes problems of huge energy consumption and poor indoor air quality. In contrast, electric fans promise an indoor cooling effect with lower energy consumption. This makes the exploration of air flow utilization significative. This paper discusses the results of a research with both an online survey and a series of climate chamber experiment to study user requirements for air movement in their daily life. The online survey results showed that electric fans were widely accepted in both homes and offices because they were environmental friendly, low-cost and could provide a fresh feeling. The results of climate chamber experiment identified suitable range of indoor temperature to use electric fans and their corresponding range of air speeds. The air flow generated by electric fans could be used as an effective cooling method to maintain a comfortable environment at 28 °C–32 °C. Compared with the acceptable range of temperature and air speeds for the comfort zone recommended by the ASHRAE Standard 55-2010, this study showed that air speeds over 0.8 m/s were acceptable and they could offset a higher temperature. With reasonable utilization, electric fans could provide a healthy and energy-efficient way to control indoor environment. [Copyright &y& Elsevier]

Abstract: Many parts of the building envelope contain enclosed airspaces. The thermal resistance (R-value) of an enclosed airspace depends on the emissivity of all surfaces that bound the airspace, the size and orientation of the airspace, the direction of heat transfer through the airspace, and the respective temperatures of all surfaces that define the airspace. The 2009 ASHRAE Handbook of Fundamentals (Chapter 26) provides a table that contains the R-values for an enclosed airspace. The ASHRAE table is extensively used by modelers, architects and building designers in the design of building enclosures. This table provides R-values for enclosed airspaces for different values of the thickness of the airspace, effective emittance, mean airspace temperature, and temperature differences across the airspace. The effect of the airspace aspect ratio (height/thickness of airspace) on the R-value is not included in the ASHRAE table. However, in a recent study on the R-value of reflective insulations using a numerical simulation model, it was shown that the aspect ratio of the airspace can affect the R-value of the enclosed airspace. The numerical simulation model used in this study had been benchmarked against experimental data obtained using two standard test methods: ASTM C-518 and ASTM C-1363. In this paper, a numerical simulation study was conducted, that was based on previous work focused on enclosed airspaces, to investigate the effect of the aspect ratio on the R-value of vertical enclosed airspaces of different thicknesses and having a wide range of values for effective emittance, mean temperature, and temperature differences across the airspace. The R-values predicted from numerical simulation are compared with those provided in the ASHRAE table. Considerations were also given to investigating the potential increase in R-values of enclosed airspaces when a thin sheet is placed vertically in the middle of the airspace and whose surfaces have different values of emissivity. Finally, practical correlations are developed for determining the R-values of an enclosed airspace for future use by modelers, architects and building designers. The simplicity of these correlations suggests that these could be included in the ASHRAE Handbook of Fundamentals. [Copyright &y& Elsevier]

Abstract: The 2010 Earthquake in Haiti caused catastrophic damage to the metropolitan area of Port au Prince. The earthquake destroyed approximately 105,000 homes, causing more than 2.3 million people to live as Internally Displaced Persons (IDPs). Today, more than 1.3 million people still live in tents. Low cost buildings can provide a housing solution for these people. This paper proposes a low cost building solution intended for hot climates, using concrete as the only material. Due to the lack of facilities at these locations, no conventional energy or cooling systems can be installed; thus, only passive cooling technologies can be used to increase thermal comfort. A low cost cool roof and combined natural ventilation is proposed, and simulations show an improvement of 16% in the thermal conditions inside the building. The simulation is performed using the software package EnergyPlus and shows that cool roofs can be a good solution for improving living conditions in low cost houses for IDPs. [Copyright &y& Elsevier]

Abstract: With the current issues concerning the management of finite energy resources and the potential savings in the building sector, reducing building energy consumption is a key point. Up to now, efforts have been focused on insulation to separate the inner ambiance from the fluctuation of the outside air temperature. Assuming that insulating a building might not be the best solution to exploit the free renewable sources of its environment (outside air temperature, sky temperature, solar radiation), a first identification step has been carried out to determine which sources should be exploited. Building energy simulations have been carried out, including several insulation levels and climatic conditions. Then, indicators have been defined in order to quantify the ability of the previous sources to cover the energy needs and the possibility for the building to exploit them. Finally, the previous indicators have been applied to the different configurations of buildings. The study shows that whatever the climate or the insulation level is, some resources such as the sun and the sky are not enough exploited, although some could entirely cover the building needs at each time step (case of the sky). When it is not possible, the paper proposes a method to evaluate the remaining needs and the sizing of a supplementary heating/cooling system. [Copyright &y& Elsevier]

Abstract: Flexible problem formulation is required for product model-based thermal analysis using multidisciplinary design optimization (MDO) environments for speed, accuracy, scalability, and cost-effectiveness in the Architecture, Engineering, and Construction (AEC) industry. The integration of daylighting simulation into an MDO process, however, presents several implementation challenges. In current practice, the process of an architect, engineer, or daylighting consultant to determine how to analyze a given building design for daylighting performance is frequently subjective, time-consuming, and inconsistent. Furthermore, long simulation time requirements for daylighting significantly hinder the realization of many benefits from MDO. The determination of which spaces in a building are sufficiently different to warrant an independent daylighting analysis is based primarily on building physics, building design criteria, and operating schedules (e.g. occupancy schedules). This characteristic of daylighting analysis creates the opportunity to develop intelligent mechanisms to automate the identification of the building spaces for analysis using performance-based methods, simulation of spatial results, and the scaling of spatial simulation results to whole building performance metrics in a fraction of the time it takes in current practice. Such methods would result in improved speed, accuracy, scalability, and cost-effectiveness for MDO- and non-MDO-based daylighting simulation. Currently, no such methods exist in literature or in practice. This paper fills these gaps by presenting a methodology for automated product model decomposition and recomposition for climate-based daylighting simulation using Radiance. The authors validate the research with the method''s application to several test cases and a large federal office building industry case study. [Copyright &y& Elsevier]

Abstract: Given the significant energy consumption imputable to buildings, the development of accurate models to predict building energy performance to understand their environmental impact has become a fundamental research issue. In this paper, a method for evaluating a building''s energy performance by enlarging the assessment perspective from a single building to a network of buildings is proposed and applied. The purpose of this research was to establish how a combined Inter-Building Effect (IBE) on energy consumption could work and how it could condition buildings'' energy performance when there are close spatial relationships among buildings. To examine this, a simulation of the energy performance of a whole network of buildings represented by a realistic block of twenty single-family homes subject to different climatological contexts was conducted. The results demonstrate that buildings can mutually impact the energy dynamics of other buildings and that this effect varies by climatological context and by season. The IBE analysis and the specific proposed methodology revealed energy requirement modeling inaccuracies of up to 42% in summer (in Miami, FL) and up to 22% in winter (in Minneapolis, MN). These findings demonstrate that in order to accurately predict the energy performance of a single building, the IBE created by the spatial relationship with surrounding buildings should be considered. [Copyright &y& Elsevier]

Abstract: Large glass façades are popular architectural features in building design nowadays. However, these façades can result in interior downdraught during periods with low outdoor temperatures. A rule of thumb exists to assess the downdraught risk, based on window height and window temperature . In this paper the validity of this rule of thumb is evaluated by an experimental and a numerical study. In the experimental part ten healthy male subjects (age 20–26 year) are exposed to two different downdraught conditions in a controlled climate chamber. Experimental results are also used to validate the numerical models. In the numerical (Computational Fluid Dynamics) part a parameter study has been performed to assess the influence of window height and window surface temperature beyond the range tested in the climate chamber. In addition, different floor temperatures have been investigated to evaluate the effect of floor heating as a possible design option to prevent downdraught. Based on both experimental and numerical results the existing rule of thumb is shown to be conservative. Furthermore, the numerical results reveal that an increased floor temperature (i.e. floor heating) can increase the downdraught risk. Therefore, it is recommended to modify the rule of thumb by incorporating the floor temperature as a parameter. [Copyright &y& Elsevier]

Abstract: Global warming and its effects on climate are of great concern. Climate change can affect buildings in different ways. Increased structural loads from wind and water, changes in energy need and decreased moisture durability of materials are some examples of the consequences. Future climate conditions are simulated by global climate models (GCMs). Downscaling by regional climate models (RCMs) provides weather data with suitable temporal and spatial resolutions for direct use in building simulations. There are two major challenges when the future climate data are used in building simulations. The first is to handle and analyse the huge amount of data. The second challenge is to assess the uncertainties in building simulations as a consequence of uncertainties in the future climate data. In this paper two statistical methods, which have been adopted from climatology, are introduced. Applications of the methods are illustrated by looking into two uncertainty factors of the future climate; operating RCMs at different spatial resolutions and with boundary data from different GCMs. The Ferro hypothesis is introduced as a nonparametric method for comparing data at different spatial resolutions. The method is quick and subtle enough to make the comparison. The parametric method of decomposition of variabilities is described and its application in data assessment is shown by considering RCM data forced by different GCMs. The method enables to study data and its variations in different time scales. It provides a useful summary about data and its variations which makes the comparison between several data sets easier. [Copyright &y& Elsevier]

Abstract: The effect of near-field pollutant dispersion characteristics for the case of downstream buildings in the urban environment has been presented in this paper. Wind tunnel data were obtained for nine different building configurations, three exhaust momentum ratios (M) and three stack heights (h s), for wind azimuth of 0°. Tracer gas concentrations were measured on the roof, windward and leeward walls of each building. When a tall downstream building was located within the recirculation length of the emitting building, higher rooftop concentration was measured on the emitting building than for the isolated building case. Results also show that the height and across wind dimension of the downstream building, as well as the spacing between buildings are critical parameters in assessing plume dilution. ASHRAE 2007 and ASHRAE 2011, which apply Gaussian-based models for the evaluation of dilution, are unable to model the effect of adjacent buildings; the former yielded lower dilution for all cases examined whilst the latter was found to be suitable only for specific limited cases. Design guidelines for the placement of stack and intakes to avoid or minimize plume re-ingestion are proposed. [Copyright &y& Elsevier]

Abstract: Human behaviors and capabilities during fire evacuations can be significantly influenced by the environmental conditions such as building layout and smoke distribution, and therefore the human behavior modeling must be based on the considerations of these features. This paper presents an indoor fire evacuation model which enables a comprehensive representation of interacting essential variables, i.e. building environment, occupants and combustion products. GIS (Geographic Information System) technology has been applied in the model to analyze the distributions of the essential variables and support the modeling of human-fire interactions, which include human evacuation behaviors and fire gas hazards. Seven categories of behaviors, namely pre-evacuation activities, evacuation, following the crowd, moving through, crawling, turning back and waiting, were modeled based on the design and combination of the formulated rules. The incorporation of spatial analysis and reasoning into rule-based behavior modeling allows the simulated behaviors to adapt to the development of fire environments. Finally the simulation results, presented quantitatively, were visualized in a 3D environment in which virtual fire scenarios were created in real time. An example of simulation demonstrates that use of the model can testify building plans regarding fire safety and improve the understanding of fire evacuation process. [Copyright &y& Elsevier]

Abstract: The present paper shows the results of a literature survey aimed at exploring how the indoor environment in buildings affects human comfort. The survey was made to gather data that can be useful when new concepts of controlling the indoor environment are developed. The following indoor environmental conditions influencing comfort in the built environment were surveyed: thermal, visual and acoustic, as well as air quality. The literature was surveyed to determine which of these conditions were ranked by building users as being the most important determinants of comfort. The survey also examined the extent to which other factors unrelated to the indoor environment, such as individual characteristics of building occupants, building-related factors and outdoor climate including seasonal changes, influence whether the indoor environment is evaluated as comfortable or not. The results suggest that when developing systems for controlling the indoor environment, the type of building and outdoor climate, including season, should be taken into account. Providing occupants with the possibility to control the indoor environment improves thermal and visual comfort as well as satisfaction with the air quality. Thermal comfort is ranked by building occupants to be of greater importance compared with visual and acoustic comfort and good air quality. It also seems to influence to a higher degree the overall satisfaction with indoor environmental quality compared with the impact of other indoor environmental conditions. [ABSTRACT FROM AUTHOR]