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Highlights • A total of 925 papers were searched and 106 articles were screened for deep review. • Green buildings generally performed better than the conventional counterparts. • A significant gap between the designed and operational energy use was found. • The key findings of objective IEQ and occupant satisfaction were summarized. • The performances of green buildings in China and the U.S. were compared. ABSTRACT This paper aims to review the published researches on post-occupancy performance of green buildings in terms of energy use, indoor environment quality (IEQ) and occupant satisfaction. A total of 925 related papers were searched and 106 articles were screened for deep review. The study also compared the actual operating performance of green buildings in China and the United States, with information collected from previous research. The findings of literature review can be summarized as follows: 1) Though with some exceptional cases, the energy performance of green buildings was on average better than the conventional counterparts with similar climate conditions; 2) A significant gap between the designed and operational energy consumption was found, and lots of green buildings saved less energy than expected; 3) No clear relationship between the actual energy use and the green building certification level could be observed; 4) The actual IEQ conditions of green buildings were not comparable in different countries due to the variance in design criterions and operation modes; 5) Green buildings generally had higher occupants' satisfaction level than conventional buildings, although the subjective data from the U.S. did not support this inference. Furthermore, this study proposed two areas worthy further investigations in the field of post-occupancy evaluation on green buildings, including new data collection technologies and performance optimization at the comprehensive level. [ABSTRACT FROM AUTHOR]

Highlights • A new experimental procedure to test PCM-enhanced components is presented. • A modified Dynamic Heat Flow Meter Apparatus is used to perform the tests. • The thermal conductivity of PCMs is measured in different phases (solid-liquid). • Indications to solve the issues related to building PCM-specimens are provided. Abstract The implementation, in Building Performance Simulations (BPS) tools, of robust models capable of simulating the thermophysical behaviour of a Phase Change Material (PCM) represents a fundamental step for an appropriate thermal evaluation of buildings that adopt PCM-enhanced envelope components. Reliable and robust measuring procedures are essential, at a material and component level, to provide experimental data for the empirical validation of software tools. The traditional laboratory tests that are generally used for the validation of models present some limitations, because PCMs are usually subjected to conditions that may be very different from the real boundary conditions of the building components in which PCMs are applied. Furthermore, in many experimental full-scale mockups, the relatively small quantity of installed PCM and the combination of several thermal phenomena do not allow software tools to be tested in a reliable way. In this paper, an experimental procedure, based on a modified Heat Flow Meter Apparatus, has been developed to test the behaviour of PCM-enhanced components; the procedure, which is based on the measurement of the sinusoidal response, has been set up to provide data for the comparison and testing of numerical models and of BPS tools. Moreover, general indications and guidelines are provided to solve some issues related to building specimens that contain bulk PCM in order to obtain a more accurate measurement of their performance. The experimental results presented in this paper were obtained from two different bulk PCMs (organic and inorganic). It was found that it is important to evaluate different PCM typologies and different thermophysical boundary conditions, including partial and full phase transitions, to test simulation codes that implement PCM modelling functions. In fact, some phenomena, such as hysteresis and subcooling effects are more evident when partial phase transition takes place. The results related to the characterization of the thermal conductivity of a paraffin-based PCM have shown a significant increase (up to 42%) of the equivalent thermal conductivity from a solid to a liquid state, with an upward heat flux, thus highlighting that further investigations and improvements are needed to measure the equivalent thermal conductivity in the different PCM phases. [ABSTRACT FROM AUTHOR]

The building sector is responsible for several environmental impacts, as well as economic and social consequences. Hence, the adoption of energy efficiency measures in building renovation projects can lead to benefits to several stakeholders in a holistic sustainability perspective. However, these projects require a gradual shift of their business models towards sustainable business models. In particular, performing quantitative sustainability analyses can help to overcome the traditional focus of business models on economic value and customers by defining wider costs and benefits for the environment and the society. This paper first provides a review of the state-of-the-art of sustainability analyses and business models for building renovation projects. Then, it proposes an analytic process based on the execution of quantitative sustainability examinations, as a support for the project proposition, creation, and capture of sustainable value in a multi-stakeholder perspective. The analytic process is applied to a case study that is the energy renovation project of a Norwegian single-family house, and several sustainability criteria are computed for three possible scenarios that are inclusive of different energy efficiency measures. The paper's findings can be relevant for both practitioners and academics who search for new approaches to embed quantitative analyses into the business context of building energy renovation projects. Furthermore, the findings can represent the groundwork for the possible operationalization of sustainable business in such projects, striving for a systematic execution of quantitative sustainability analyses as a key step towards sustainable business models. [ABSTRACT FROM AUTHOR]

Reducing energy consumption in buildings and increasing renewable production are key goals of European policies to achieve a sustainable and competitive low-carbon economy by 2020 and beyond. Non-residential buildings constitute a heterogeneity sector characterized by high energy consumption and various building types, sizes and energy characteristics over Europe. This paper presents the overall results of the data collected by the GreenBuilding Programme (GBP), launched in 2006 to promote and improve energy efficiency in new and existing European non-residential buildings. The GPB involved building owners willing to adopt energy efficiency measures to decrease energy consumption of their buildings by of at least 25%. Based on voluntary participation, hundreds of partners joined the project, which collected data from more than a thousand buildings of different age, size, use and type (such as offices, hotels, and industry). This paper provides an overview of the Programme and its main results up to its completion in 2014. The paper focuses on building characteristics, energy performance, efficiency measures and energy savings, which are globally estimated to be around 985 GWh/year. A more detailed focus is then given to office buildings, which represent the most frequent building category in the Programme. Case studies are presented to show best practices in various countries with consolidated energy efficiency policy strategies. The paper categorises the main technological measures related to envelope, appliances and systems. It shows how a wide range of technologies are becoming an integral part of buildings and how technology plays a major role in exploiting the massive potential benefits of reducing building energy consumptions. The analysis of the results generates a reliable snapshot of European non-residential building stock. [ABSTRACT FROM AUTHOR]

The energy policies in Europe include the reduction in energy consumption of buildings along with their environmental impact, focusing mainly on CO 2 emissions. In this framework, solar thermal systems used for space heating purposes and Domestic Hot Water production will be studied in detail. Solar thermal systems are one of the most popular ways to provide sanitary hot water in hotel buildings, all over the world and in particular in the Mediterranean. This is due to the fact that over the last forty years they have been proven to be reliable and cost effective. Still, there is more to those systems, than cost efficiency, as it will be discussed in this paper, based on a study carried out for the Greek hotel sector. The analysis of the solar thermal system was done on the basis of technical characteristics and their energy efficiency as well as of the potential energy saving and their environmental impact, focusing mainly on CO 2 emissions. The environmental evaluation of the system studied is expressed by means of an integrated environmental approach, based on environmental rating systems namely LEED and BREEAM. Goal of the paper is to present the result of the overall evaluation of the solar thermal system and its contribution to the improvement of the building's energy and environmental performance and also discuss how this affects the building's respective certification. [ABSTRACT FROM AUTHOR]

Mandatory civil building energy efficiency codes strictly govern the energy consumption of new buildings in China. As the promotion of building energy efficiency in China has increased in recent years, compliance with mandatory civil building energy efficiency codes has also improved, increasing from less than 10% in 2000 to nearly 100% in 2012, a remarkable achievement. However, because the promotion of energy efficiency strategies in China has followed a unique pattern, some researchers doubt these statistics. In response to these doubts, this paper summarises and analyses the framework of measures implemented by the Chinese government to enforce mandatory building energy efficiency codes. First, the development and implementation of China's mandatory civil building energy efficiency code system is summarised. Second, the building supervision and inspection systems used to assess energy efficiency are introduced and analysed in detail in order to provide a framework for the development of energy policies in other countries. Third, the assessment and reporting processes used to determine compliance rates are reviewed. Finally, the improvement of compliance rates and its impact on building energy savings in China are discussed. Along with the increase in compliance rates in the construction stage from 71% in 2007 to 100% in 2012, the energy savings of new buildings per increased floor area per year increased from 20.4 kWh/m 2 to 28.4 kWh/m 2 . The supervision and inspection systems reported in this paper are the keys to enforcing building energy efficiency codes. [ABSTRACT FROM AUTHOR]

This paper analysed the results and the status of China's building energy efficiency, explored the new areas of building energy in future: the industrialized composite wall on construction. As China is engaginga process of rapid urbanization,it is believed thatlarge amount of construction will continue for 25-30 years, and all of new buildings must be strictly in accordance with the standards of energy-saving by 50% or 65% in the processes of design and construction. Chinese construction industry is currently implementing the “Four Savings and Environment Protection” policy, which requires energy, land, water and materials saving and environmental protection in every building project. In Heilongjiang Province, as other areas in China, the requirements of energy-efficient design have been comprehensively and strictly implementedon the new buildingssince 2000. By 2010, energy-efficient design has been completely popularized in all kinds of new buildings by 50% energy saving compared with the same type of buildings built in 1980s. According to the requirements of the Ministry of Construction, in the future the further energy efficiency targets should be increased from 50% to 65%, meanwhile the main field of building energyefficiencywill been changed from the initial entry points such as the thermal insulation of externalwall, roof, doors and windows to further wide areas, such as the Optimization of building material, component manufacturing, construction quality and method, all of which could be realized by the industrialized composite panels and walls completely. Industrialized composite panels and wallsbring thoroughgoing innovationson wall materials and construction, the improvementof the construction accuracy, so that the wall thermal insulation performance is much higher than traditional buildings. Due to the productionconcentrated in the factory and the batch processing, the energy consumption ofbuilding industrialization is much lower than the traditional human construction at the construction site. The industrialized composite panel and wall of buildings can reduce the loss of the main materials of construction,the assembling construction reduce the loss of Secondary buildingmaterials. Compared with traditional construction methods, building industrialization of the composite panelrealizesthe field fabricated construction, which greatly minimizes the generation of construction waste, building waste water emissions, construction noise interference, harmful gases and dust emissions, and so on. The Building industrialization could maximize the improvement of the quality of components and assembly precision, and effectively reduce the roof leaks, wall cracks, quality defects of wall and window such as cold air infiltration, so the architectural quality and accuracy can be improved significantly. Factory production and on-site assembling of prefabricated components can reduce the workers of construction site and management, saving a lot of labor costs. Building industrialization transfer most of the operation to production line, saving construction cost and schedule greatly. It is particularly important to the construction in cold areas. Moreover, three types of building composite walls and panel are introduced. In this paper, composite walls and panel include composite material, composite structure or both of them applied in the wall and panel. The first kind of composite wall is the straw board. The straw board is clean, which is made of natural straw or wheat straw as the main raw material. This kind of straw board is mainly used for internal and external walls of the building and roof of the building, etc. Straw board whichis regarded as wall materials generally does not work as load-bearing walls. When it comes to application, the surface should be decorated to ensure that its fire, moisture, fire-retardant abilities. Straw board is not only suitable for load-bearing frame structure buildings, including civil construction, light industrial plants, but also for the old buildings which need to be rebuild, storage buildings and temporary buildings, etc. It is a lightweight, high strength, thermal insulation board which is new and environmentally friendly, particularly suitable to use in cold regions construction. The second example is the HS-EPS core column structure system, whichis invented by Harbin Hong Sheng housing energy system research and development centre with the whole intellectual property patents. This system consists of base beam, EPS moulded wall composed with core column of reinforced concrete, eaves ring beam and roof trusses and other components, is suitable for various types of single storeybuildings.EPS module consists of polystyrene beads by heating and foaming, through a dedicated heat moulding equipment and moulds in the system with closed-cell structure of different types, different specifications and different shape. The modules are rectangular, which internal and external surfaces distribute the uniform dovetails. There are two bridges connecting the fixed plug door in the middle of three 200 mm × 240 mm rectangular hole, both inside and outside of the hole wall thickness is 50 mm. In 2010, itwas applied in Piaohe town as a pilot project and in Antu County as 800 post-disaster housing, where thissystem has been widely recognized. The third sample is Gao Ge Composite Panel of Husk Mortar, with the both advantages of composite material and composite structure. This panelis precast, made from light husk mortar, welded wire mesh and steel as the skeleton, and thermal, noise insulation layers. The husk mortar is made of cement, sand, husks and water by mixing. This panel can be used to the wall-bearing housing, and multi-storied and high-rise reinforced concrete frame construction as the envelope, its overall size is the same with the external wall of a room, as in Four sides of the panel are joined with the beams and columns of the buildings. The wall panel consists of two surface layer of husk mortar, and two insulation layer (benzene or rock cotton) and a air layer inside. The two surface layers are connected by the vertical and horizontal reinforced ribs, and the insulation layers are spliced inside by mortar, each small insulation board was totally fixed by insulation mortar from 5 surfaces. The cavities between two insulation layers are supported by the ribs. [ABSTRACT FROM AUTHOR]

Zero-energy buildings (ZEBs) are attracting increasing interest internationally in policies aiming at a more sustainably built environment, the scientific literature and practical applications. Although “zero energy” can be considered at different scales (e.g., community, city), the most common approach adopts only the perspective of the individual building. Moreover, the feasibility of this objective is not really addressed, especially as far as the retrofitting of the existing building stock is concerned. Therefore, this paper aims first to investigate the opportunity to extend the “zero-energy building” concept to the neighbourhood scale by taking into account two main challenges: (1) the impact of urban form on energy needs and the on-site production of renewable energy and (2) the impact of location on transportation energy consumption. It proposes a simplified framework and a calculation method that is then applied to two representative case studies (one urban neighbourhood and one rural neighbourhood) to investigate the feasibility of zero-energy in existing neighbourhoods. The main parameters that act upon the energy balance are identified. The potential of “energy mutualisation” at the neighbourhood scale is highlighted. This paper thereby shows the potentialities of an integrated approach linking transportation and building energy consumptions. [ABSTRACT FROM AUTHOR]

Abstract: The increasing European Union legislation on building and energy services and widespread adaptation on energy labeling and certification provides a unique opportunity to analyse characteristics of building stock at micro and macro level. Thus there is a need to handle large database in order to extract trends and performance statistics. The European DISPLAY campaign is a voluntary scheme aimed at encouraging local authorities to publicly display the energy and environmental performances of their public buildings. The underlying hope is that participating in the DISPLAY certification campaign will lead to significant improvements in the energy performance of municipal buildings. This paper addresses the issue of energy certification through presenting trends in building ratings for energy, CO2 and water. Paper also gives glimpse of trend for performance of buildings using simple methodology. Encouragingly the clear trend over time is that there has been an increase in the number of A rated energy certificates, and steady decrease in the number of both F and G rated energy certificates. However, the emphasis of this paper will be on the improvements and deteriorations experienced by specific buildings. Having assigned a numerical value to each ‘grade’, method has been identified to measure the building energy performance. [Copyright &y& Elsevier]

Highlights • Impacts of fouling and ambient temperature on ASHP's performances were studied. • Increased fouling level and ambient air temperature led to poorer performances. • An equivalent temperature rise due to fouling was proposed and evaluated. • An improved simulated fouling approach was experimentally validated. Abstract Air source heat pumps (ASHPs) have been widely used for providing buildings with heating in winter and cooling in summer. In certain locations, with an increased level of air pollutions, fouling of the outdoor coil in a space cooling ASHP unit may appear, which affects the operating performances of the ASHP unit. Furthermore, the operating performances of an ASHP unit can also be affected by ambient air temperature (T a). In this paper, a field study on the effects of outdoor coil fouling at different T a on the operating performances of a field space cooling ASHP unit is presented. The study results demonstrated that the operating performances of the field ASHP unit were significantly affected by the changes in both T a and percentage of fouled outdoor coil surface (PFOCS). For example, at T a = 30 °C, the variation in PFOCS from 0 to 100% led to a reduction in COP for the field ASHP unit from 2.7 to 2.0. At a fixed PFOCS of 60%, the changes in T a from 26 to 33 °C resulted in a reduction in COP from 2.6 to 2.1. In order to more conveniently investigate the combined impacts of fouling on the operating performances of an ASHP unit at different T a , an equivalent ambient air temperature rise (ETR) was proposed. Based on the measured and evaluated operating parameters of the field ASHP unit at different T a and PFOCS values, ETR values at 0 - 40%, 40 - 60%, 60 - 100% and 0 - 100% PFOCS ranges were evaluated. These ETR values implied that defouling of a fouled outdoor coil may be initiated when PFOCS was at 40 - 60%. With the ETR values for the full PFOCS range of 0 - 100%, the impact of full fouling on the operating performances of an ASHP unit may be evaluated as if it was operated with a clean outdoor coil but at an equivalent ambient air temperature of T a + ETR. [ABSTRACT FROM AUTHOR]

Highlights • A methodology is introduced to rank a set of buildings based on energetic performance of occupants. • Ranking is done in two levels, each one gives specific information about occupants of a single building. • The underlying factors that create the ranks are examined to give occupants clues on how to improve their rank and reduce energy consumption. Abstract Identifying the impacts of occupants on building energy consumption has become an important issue in recent years. This is due to the interrelationship of influencing factors such as urban climate, building characteristics, occupant behavior, and building services and operation, which makes it challenging to identify the role of occupants in energy consumption. The research problem in this study lies in the fact that the occupants of a building may not be cautious regarding energy savings, and there exists no ground to assess their energy consumption behavior. One solution is the development of a systematic comparison procedure between similar buildings. This paper introduces a new procedure for comparison between occupants of several buildings to show the rank of each building among others and suggest occupants on reducing their energy consumption and improving their rank. The proposed framework is developed based on multiple data-mining methods, including clustering, association rules mining, and neural networks. The proposed methodology is composed of two levels. The first considers the amount of energy usage by occupants after filtering effects unrelated to the occupant behavior. The second ranks the buildings in terms of achieved and potential savings during the time under investigation. To demonstrate the application, the methodology was applied on a set of monitored residential buildings in Japan. Results suggest that the proposed method enhances the evaluation of buildings' energy-saving potential by revealing the occupants' contribution. It also provides diverse and prioritized strategies to help occupants manage their energy consumption by revealing the building energy end-use patterns. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Highlights • Our equivalent wall method uses the structure factors and harmonic heat fluxes. • The method is tested on three 2-D thermal bridges. • The comparison is based on numerical simulations results. • For a realistic, severe or step evolution of outside temperature, results are precise. • Equivalent walls results are much better than those for a classic 1-D evaluation. Abstract This paper presents a mixed method to determine a 1-D three-layer wall having the same static and dynamic behaviours as a multidimensional thermal bridge. It is based on the calculations of thermal resistance, heat capacity, structure factors and an objective function using harmonic heat fluxes features. This mixed method is applied to three 2-D details. The heat flux through inner surface is analysed over time for a step solicitation and for given boundary conditions: a sinus evolution of the inside temperature and a severe or a more realistic evolution of the outside temperature. Results are really satisfactory, evolution of heat flux through the thermal bridge is close to that of the corresponding equivalent wall. For an outside temperature profile (T e) close to real data, the error on integral value of heat flux is less than 1% in each case. The results for equivalent walls are significantly better than for a classic 1-D evaluation: for a severe evolution of T e the average error is 6 to 28 times lower in the tested cases. [ABSTRACT FROM AUTHOR]

Abstract Sensitivity analysis (SA) can be applied to building energy models (BEM) to identify which input parameters that drive the majority of the model output variation. The screening-based Morris method is often applied for this purpose; however, consideration regarding the effect of the user-defined number of levels (p) and trajectories (r) on the obtained results are rare. This paper investigates how the choice of p and r affects the outcome of a SA using the Morris method on a high fidelity BEM. The results indicates that the Morris method was not able to replicate the ranking from the variance-based Sobol' method no matter the choice of r and p. It was, however, able to identify groups of input parameters (parameter clusters) most sensitive to the model output variability, but it required significantly more r than usually applied in studies featuring the Morris method. The reason is that marginal differences in absolute values of elementary effects (the sensitivity indices of the Morris method) for some input parameters may lead to a change in ranking position several times as the number of r increases. Users of the Morris method must therefore not be predetermined on the size of the parameter cluster; instead, they must make a visual assessment of the convergence of the parameter ranking to qualitatively determine the appropriate size of parameter cluster. The final recommendation for future studies deploying the Morris method for SA applied to a high fidelity BEM is to choose p ≥ 4 as it seems to lead the analysis towards a more truthful ranking, and then run simulations in steps of r = 100 when making the visual assessment to determine convergence and the size of parameter cluster. The identified need for more r questions the general notion that the Morris method is a computationally efficient screening method in terms of absolute time use. However, the Morris method is still much more computational efficient than a Sobol'-based analysis if the purpose of the SA is to identify a cluster of input parameters most sensitive to the model output variability. [ABSTRACT FROM AUTHOR]

Highlights • Analysis of the average temperature dependency of thermal conductivity in VIPs. • Analysis of the heat transfer contributions that affect thermal conductivity in VIPs. • Evaluation of the combined effect of ageing and temperature on thermal conductivity. • Impact of thermal conductivity variation on thermal behaviour of a VIP-based roof. • Measures to mitigate severe conditions for VIP-based components were introduced. Abstract Over the last few years, the adoption of Vacuum Insulation Panels (VIPs) in building envelopes has increased. However, in order to obtain a correct implementation of VIPs in buildings, it is crucial to conduct a proper analysis of the thermal bridging, the service life and the ageing effects at both the design stage and during building operation. A further factor that should be considered is the dependency of thermal conductivity on temperature. In this paper, an experimental campaign has been carried out to evaluate the variation in the thermal conductivity of VIPs with the average temperature and to qualitatively assess the heat transfer contributions that affect this variation. The study has also been devoted to evaluating the effect of a variation in the thermal conductivity considering various VIP ageing stages. Moreover, dynamic heat transfer simulations have been performed, using a validated model, to investigate the impact of considering a temperature dependent thermal conductivity on the overall thermal behaviour of a building roof with VIP-based insulation. [ABSTRACT FROM AUTHOR]

Highlights • Effect of nonlinear dynamics of a hydronic heat emitter on the DR potential. • The nonlinear thermal effects had insignificant effects on the DR performance. • Shifting potential depends on the energy efficiency of the building envelope. • A reliable radiator model suitable for any simulation-based research is proposed. Abstract Existing simulation-based studies on applying model predictive control (MPC) schemes for space heating operation to enable demand response (DR) make use of linear models for the heating system, usually by assuming convective electrical baseboard heaters. However, buildings connected to district heating networks are typically equipped with hydronic heat emitters, such as radiators, that behave nonlinear. This paper therefore investigates the effect of including the nonlinear dynamics of a hydronic heat emitter on the DR potential of MPC for space heating. Furthermore, the performance of a practical two-level control approach suitable for real application, in which a heating setpoint was determined by a linear MPC and communicated to a conventional proportional integral controller, was investigated. The simulation framework for the investigation was based on the application of an experimentally obtained hydronic radiator model applied in different co-simulation setups, featuring a model of a poorly and a highly insulated apartment, respectively. The results indicated that inclusion of the nonlinear thermal effects of hydronic radiators did not significantly affect the DR performance when compared to the results of an MPC scheme controlling convective electrical baseboard heaters. In general, both setup achieved operational cost savings of approx. 5% and 18% in an existing and retrofitted building, respectively, while restricting the amount of thermal comfort violations to a limited extent. This suggests that results obtained in previous studies featuring electrical baseboard heaters also apply to buildings equipped with hydronic heating systems, and that future simulation-based studies and practical implementation of MPC for space heating can continue to rely on the use of far less computationally demanding linear control-models. Furthermore, the results suggest that the two-level control scheme seems like an appropriate control setup suitable for real applications. [ABSTRACT FROM AUTHOR]

Abstract Energy demands of current buildings present an important problem for building designers and engineers. However, the necessity to retrofit building envelopes and achieve a better thermal performance is substantially limited by the economic viability. Despite of the environmental benefits accompanied with enhanced thermal stability, a complex evaluation of the impact of reconstruction works from various perspectives is still needed. In this paper, a quantification of physical, social, economic, and environmental benefits resulting from the application of exterior thermal insulation system to an institutional building is presented. The temperature profiles in the wall cross-section are used for the assessment of the effect of expanded polystyrene boards. The annual energy consumption and carbon emission production is found to decrease by 46% as the result of better thermal performance. The improved social comfort is confirmed by the evaluation of predicted mean vote characterizing the average heat sensation of building occupants. The carbon payback of 3.24 years refers to low initial environmental burden in proportion to obtained energy savings. However, full investments recovery rate varying from 43 to 60 years in dependence on applied economic scenarios reaches almost the lifetime of used materials, which presents a substantial barrier despite of the discounted cost savings of 180,000 Euros during the 60-year lifespan. [ABSTRACT FROM AUTHOR]

Building life cycle assessment (LCA) aims at guiding decision towards more sustainable alternatives of a building project. But, in order to successfully reduce the high environmental impacts of the building sector, the results of building LCA have to be robust. Sensitivity analysis (SA) helps at investigating the sources of uncertainty and variability in a model and assessing the results' robustness. Choosing an adapted SA method remains difficult: using the more precise SA methods would require a too large calculation time, particularly for an application in early design phase. In this paper, the most influential factors of building LCA tools, linked with energy simulation tools, were investigated using screening and global SA methods that are compatible with the building LCA fields. The relative influence of the uncertain factors served as a metric to compare more precisely the results given by this large panel of methods. The results show that despite their different precision vs computational cost compromises, all the methods identified the same set of influential factors. In the studied case of a passive single family house, they consisted in the building lifetime, the electricity production mix and factors affecting the energy consumption. However, the relative influence of the factors differed. Two new method adaptations were investigated in order to obtain precise results in a reasonable simulation time. The adaptation of the Plackett and Burman (PB) screening performed well compared to the reference method (Sobol indices), as the same set of influential factors was always identified in a calculation time divided by almost 30. [ABSTRACT FROM AUTHOR]

Large scale smart meter deployments have resulted in popularization of sensor-based electricity forecasting which relies on historical sensor data to infer future energy consumption. Although those approaches have been very successful, they require significant quantities of historical data, often over extended periods of time, to train machine learning models and achieve accurate predictions. New buildings and buildings with newly installed meters have small historical datasets that are insufficient to create accurate predictions. Transfer learning methods have been proposed as a way to use cross-domain datasets to improve predictions. However, these methods do not consider the effects of seasonality within domains. Consequently, this paper proposes Hephaestus, a novel transfer learning method for cross-building energy forecasting based on time series multi-feature regression with seasonal and trend adjustment. This method enables energy prediction with merged data from similar buildings with different distributions and different seasonal profiles. Thus, it improves energy prediction accuracy for a new building with limited data by using datasets from other similar buildings. Hephaestus works in the pre- and post- processing phases and therefore can be used with any standard machine learning algorithm. The case study presented here demonstrates that the proposed approach can improve energy prediction for a school by 11.2% by using additional data from other schools. [ABSTRACT FROM AUTHOR]

This paper presents a hybrid building modelling method with a reduced modelling and calibration effort. The method combines a physics-based model, which describes the general behaviour of the system, with a machine learning algorithm trained to correct the physics-based model’s systematic errors. To exemplify the method, a highly simplified grey-box model is used as the physics-based part and a Gaussian process as the machine learning part. It is shown that the hybrid model improves the temperature and energy predictions of the grey-box model while having a lower generalization error than the pure Gaussian process. Specifically, the hybrid approach achieved a day-ahead zone temperature prediction error ca. 0.1 K (RMSE) lower than the grey-box model. As for the energy prediction, the hybrid model obtained an error of 3% compared to 8% for the grey-box model. In comparison to the Gaussian process, the hybrid approach achieved better predictions in all cases. The improvements were especially high when the models were trained with small datasets: 0.7 K in the temperature prediction and 25 percentage points in the energy prediction. [ABSTRACT FROM AUTHOR]

Historic buildings constitute a large amount of the European building stock and their preservation is of paramount importance for cultural, economic and also environmental reasons, as their conservation is regarded as more sustainable with respect to demolition and reconstruction. However, historic buildings require frequent repair and conservation works, whose environmental impact is still to be evaluated. In the present paper the sustainability of conservation intervention is evaluated by the LCA analysis method, focusing in particular on cleaning materials and technologies, with reference to conservation sites located in Bologna, Italy. After identifying the most used cleaning materials and technologies, the time necessary for achieving an equal cleaning effectiveness was selected as functional unit and the LCA analysis was carried out, along with a quantitative evaluation of some other key aspects of the different methods (workers’ health, acoustic impact and waste produced in the building site). The results highlight that the different technologies involve remarkably different environmental impacts, but that in some cases their impact could be easily reduced by substituting some secondary materials in the cleaning process, without affecting the effectiveness of cleaning. The results also show that the methods involving the lowest environmental impact are not necessarily the best ones in terms of safety and waste production in the building site. [ABSTRACT FROM AUTHOR]

Energy retrofit of existing buildings was highlighted as an efficient massive action to decrease energy consumption and emissions of greenhouse gases. But, detecting the optimal retrofit strategies for groups of buildings is nowadays a highly complex problem. Their energy consumptions are influenced by building-related factors (climate, building envelope, building services and systems) and by user-related ones (building operation and maintenance, occupant behavior, and indoor environmental quality). Detecting the contributions of each factor and grouping buildings with similarities –in order to establish similar retrofit strategies – are the main issues that can be faced by statistical multivariate methods. In this paper, we present a new and broader view to propose retrofit strategies adapted to a climate change scenario and analyzed from the economic and energy-poverty points of view, by using multivariate and clustering techniques that include building-related and user-related metrics influencing the energy consumption of groups of buildings. A group of 10 single-family houses in Argentina were selected as a case-study. The contributions of eleven building-related driving metrics and four user-related ones to the energy consumption were analyzed. Then, the more representative house of the cluster was selected for a retrofit analysis for current weather conditions and for future weather under a climate change scenario. The analysis also included an economic assessment in relation to the energy poverty. The higher CV values found in the user-related metrics highlight the influence of occupants in the energy consumption that can result in huge gaps between real and predicted energy performance of buildings. This holistic study contributes to reveal the internal structure of energy consumption and to generate useful knowledge about energy retrofit of the built environment in cities, particularly for those householders which are more susceptible to suffer the adverse effects of energy poverty and climate change. [ABSTRACT FROM AUTHOR]

Energy consumption models play an integral part in energy management and conservation, as it pertains to buildings. It can assist in evaluating building energy efficiency, in carrying out building commissioning, and in identifying and diagnosing building system faults. This review takes an in-depth look at energy-demand prediction models for buildings in that it delves into recent developments in building energy approaches used to predict energy usage. By enlisting current approaches to the modelling of buildings, methods for building energy simulations can be categorized into four level classes as follows: (i) data-driven approaches; (ii) physics-based approaches; (iii) large scale building energy forecasting approaches; and (iv) hybrid approaches. The focus of this review is to target the data-driven approach and large-scale building energy predicting-based approaches. Here the data driven approaches can be categorized by (1) artificial neural network based approaches; (2) clustering based approaches; (3) statistical and machine learning-based approaches; and (4) support vector machine based approaches. From there, the type of data-driven based approach is further grouped by (a) benchmarking models; (b) energy-mapping models; (c) energy forecasting models; and (d) energy profiling models. Large-scale building-energy prediction techniques is then categorized as follows: (1) white-box based approaches; (2) black-box based approaches, and (3) grey-box based approaches. The current study explores first-rate data-driven based approaches about building energy analysis for industrial, commercial, domestic, etc., within a rural and urban setting. This review paper is based on the necessity of identifying points of departure and research opportunities for urban and rural-level analyses of building level energy performance. A variety of issues are explored which include: energy performance metrics; end-use of different building types; multiple levels of granularity; and urban and rural scales. Each technique encompasses a variety of input information as well as varying calculations or simulation models along with furnishing contrasting outcomes that suggest a variety of usages. A thorough review of each technique is presented in this study. This review highlights strengths, shortcomings, and purpose of the methods of numerous data-mining based approaches. A comprehensive review of energy forecasting models that are specified in the literature part is also provided. [ABSTRACT FROM AUTHOR]

Developing BEPS models which predict energy usage to a high degree of accuracy can be extremely time consuming. As a result, assumptions are often made regarding the input data required. Making these assumptions without introducing a significant amount of uncertainty to the model can be difficult, and requires experience. Even so, rules of thumb from one geographic region are not automatically transferrable to other regions. This paper develops a methodology which can be used to determine useful guidelines for defining the most influential input data for an accurate BEPS model. Differential sensitivity analysis is carried out on parametric data gathered from five archetype dwelling models. The sensitivity analysis results are used in order to form a guideline minimum set of accurately defined input data. Although the guidelines formed apply specifically to Irish residential dwellings, the methodology and processes used in defining the guidelines is highly repeatable. The guideline minimum data set was applied to practical examples in order to be validated. Existing buildings were modelled, and only the parameters within the minimum data set are accurately defined. All building models predict annual energy usage to within 10% of actual measured data, with seasonal energy profiles well-matching. [ABSTRACT FROM AUTHOR]

Climatic zoning for building energy efficiency applications is an important element in building energy policy and regulations. There are several methodologies available to conduct climatic zoning, providing significantly different results. Currently, there are no procedures to assess the validity of a proposed climatic zoning, hindering the decision to use one particular climatic zoning methodology instead of another. This paper introduces a quality index and a procedure to support the validation of climatic zoning. The procedure is based on building performance simulation results concerning the building stock that is targeted in the climatic zoning policy or program. Simulation results are used to calculate a new index, the Mean Percentage of Misclassified Areas (MPMA), which assesses the quality of the zoning under analysis. The capabilities of this procedure were demonstrated by the evaluation of four alternatives for the climatic zoning of Nicaragua, obtained using different methodologies and previously reported in the literature. The building stock used in this case study is composed of a few archetypes based on typical naturally ventilated dwellings in this country. Simulations were conducted using the program EnergyPlus for a total of 328 locations in Nicaragua. Degree-hours of discomfort based on the adaptive model of ASHRAE Standard 55 were used as a performance indicator. Results indicate that zoning obtained using cluster analysis and cooling degree-days may misclassify 1 out of 5 areas in Nicaragua (MPMA around 18–20%). This study concludes that the validation procedure and proposed index are useful for highlighting qualities and deficiencies of existing climatic zoning methods, particularly when these methods are used in less conventional applications, such as for policy making targeting naturally ventilated dwellings in tropical climates. The application of this procedure in more than 50 countries which adopt climatic zoning is foreseen as the next step in his area, substantially affecting the prescription of building materials and components worldwide. [ABSTRACT FROM AUTHOR]

With the accelerating pace of urbanisation around the world, the planning, development and operation of buildings and precincts have become increasingly important with respect to energy use and the associated carbon footprint of the modern built environment. Over recent decades, much effort, both in research and in practice, has been devoted to building construction and urban planning for the improvement of energy efficiency and greenhouse gas emissions. However, the accuracy of modelling and evaluation of energy and carbon performance for buildings and urban precincts remains limited, affected by inadequate energy intensity data and highly integrated building systems, as well as the complex interactions between buildings and the urban eco-system. This paper presents a critical review of current measures and models for representing and assessing life cycle energy as well as associated emissions profiles at both the building and the precinct levels. It also identifies influential factors and explores interactions among buildings, surrounding environment and user behaviours at the urban precinct level by taking a systems perspective. Based on such a review, this study maps out some key challenges for integrating energy and carbon metrics, and finally proposes a precinct-level system boundary definition and an integrated model following systems thinking. The proposed model can facilitate a critical thinking approach about the evaluations of global energy and emissions, and support the quantification of energy consumption and associated emissions for building precinct systems. [ABSTRACT FROM AUTHOR]

Green building assessment methods, which play an essential role in promoting the development of green buildings, have attracted much attention in recent years. Many studies have been conducted on the development of new assessment methods and improvement of existing ones through comparative analysis. However, there is no comprehensive study that explicitly explores these efforts. For this purpose, a systematic review of the existing literature on green building assessment methods through comparative analysis is carried out in this paper. The main contributing authors as well as represented countries and areas are investigated. The comparison rules, including the number of comparative assessment methods and high frequency assessment methods, as well as the current status of comparison topics are explored. Finally, some research opportunities are proposed for future development. The research results would serve as a useful reference for both industry practitioners and academics who are interested in the development of green building assessment methods. [ABSTRACT FROM AUTHOR]

Integration of CCHP systems into large buildings provides considerable advantages, as far as the economy, energy consumption and environment related issues are concerned. In this paper, the integration of a hybrid CCHP system into a commercial building is studied. The hybrid CCHP system consists of a renewable and a non-renewable CHP component, photovoltaic/thermal (PV/T) panels and internal combustion engine (ICE). Three objective functions are considered based on cost saving, energy saving and emission reduction goals where are determined as annual operating cost ratio (AOCR), primary energy saving ratio (PESR) and carbon emission reduction ratio (CERR). Considering each objective function, the GA optimization is applied in three different approaches as a single objective optimization problem to find the best size of the system components. Then, using Analytic Hierarchy Process (AHP), which is one of the most used Multi-Criteria Decision Making (MCDM) procedures, the most profitable answer is determined from the three answers achieved in the optimization process. The results showed a good performance of the system. In PESR optimization, which is selected as the best system size, values of 32.96%, 17.25% and 14.79% was achieved for AOCR, PESR and CERR, respectively. [ABSTRACT FROM AUTHOR]

The overall energy performance of existing buildings is an important consideration in decisions to demolish or refurbish. To refurbish means to use sustainable technologies (STs) to improve energy efficiency, health of occupants, energy cost and environmental sustainability. This paper examines the use of STs to streamline energy efficiency in existing buildings. It analyses various buildings of different ages retrofitted over the last 5 years and the various STs used to enhance energy efficiency through an in-built case study in a survey. The results show that buildings less than 15 years old have been improved with fewer façade technologies compared to those between 16-30 years old. Overall, buildings aged between 16-30 years are the most improved with STs followed by buildings less than 15 years old and those between 31-45 years, in that order. Buildings over 45 years are the least improved with STs for energy efficiency. They had received less than 10% of ST technology injection. The lighting systems, sensors, energy efficient equipment and passive strategies have been applied improve energy efficiency across all ages. However, solar technologies, HVAC systems, façade technologies and building management systems are the least adopted across all ages [ABSTRACT FROM AUTHOR]

Buildings tend to not operate as intended, and a pronounced gap often exists between measured and predicted environmental and energy performance. Although the causes of this ‘performance gap’ are multi-faceted, issues surrounding data integration are key contributory factors. The distributed nature of the Architecture, Engineering and Construction (AEC) industry presents many challenges to the effective capture, integration and assessment of building performance data. Not all building data can be described semantically, nor is it feasible to create adapters between many different software tools. Similarly, not all building contextual data can easily be captured in a single product-centric model. This paper presents a new solution to the problem based upon a hybrid architecture that links data which is retained in its original format. The architecture links existing and efficient relational databases storing time-series data and semantically-described building contextual data. The main contribution of this work is an original RDF syntax structure and ontology to represent existing database schema information, and a new mechanism that automatically prepares data streams for processing by rule-based performance definitions. Two test cases evaluate the concept by 1) applying the hybrid architecture to building performance data from an actual building, and 2) evaluating the efficiency of the architecture against a purely RDF-based solution that also stores all of the time-series data in RDF for a virtual building. The hybrid architecture also avoids the duplication of time-series data and overcomes some of the differences found in database schemas and database platforms. [ABSTRACT FROM AUTHOR]

Non-residential buildings like healthcare ones contribute to energy consumption and cause a negative environmental impact. This is mainly due to the age of the buildings, their poor level of energy efficiency and the implementation of only a basic maintenance plan. Owing to the very limited budget available for public administrators, Energy Performance Contracting (EPC), that entails the involvement of an Energy Service Company (ESCo), can provide the entire or part of the capital needed for investments aimed at progressively increasing energy efficiency over their service life. In this paper, three acute hospitals and two community clinics built in Italy are analysed, in order to assess the economic feasibility of several energy renovation actions that can be included within EPC contracts. To this purpose, the outcomes of energy audits carried out in 2014 about these buildings are reported, which involved analyses of consumption measured over the previous three years and assessment of use profiles for the development of models to break down the overall consumption and to estimate potential savings. Diverse improvement strategies were assessed, consisting in either isolated or combined renovation actions and tested on the five buildings, whose comparison was carried out in terms of energy saving, pollution reduction and economic feasibility. As a result, the best combined renovation actions per each hospital were recommended, that included – but were not limited to – the improvement of the control and regulation of existing sub-systems without replacement, partial replacement of other sub-systems and integration of renewables. Finally, each scenario was evaluated through the payback period and other economic performance indexes in order to assess the feasibility of the EPC framework when applied to this case study. [ABSTRACT FROM AUTHOR]

The rapid increase of energy use has caused great concerns of resource depleting, greenhouse gas emitting, and economic difficulties. In U.S, building sector contributes 39% [33] of the total energy consumption, exceeding the other major sectors such as industries and transportation. In order to relieve the environmental and economic pressure, high performance buildings are broadly implemented recently because they are energy efficient and have less negative impact of the built environment on human health and natural environment. This paper presents the work of the thermal performance modeling and analysis for an athletic training facility located at Purdue University, West Lafayette, Indiana. The goal for this study is to predict energy consumption of the building for heating, cooling, lighting, and indoor equipment. Furthermore, the study aims to identify sustainable measures to reduce energy consumption and operation cost for the new building built based on latest ASHRAE standards. The building modeling was developed in Designbuilder, a software developed for building performance analysis. The base case of the building model was in accordance with the design standard ASHRAE 90.1-2013. The parametric analyses were conducted to determine possible improved design parameters. By comparing parametric cases, a couple of sustainable design measures were identified to improve building energy efficiency and thermal comfort. As a result, it was found that as a building with large portion of curtain wall, the weak point for this building lies on the windows and the tightness of the building. Improving window and the tightness can significantly reduce the energy consumption of the building. [ABSTRACT FROM AUTHOR]

Industrial halls pose high energy saving potential that is not yet explored under current design practice. Common design approaches such as parametric study or optimization are largely constrained by the assumptions and do not promote flexibility in the decision making process. Based on the unique characteristics of industrial halls, this paper develops a full factorial design space exploration approach to support multi-criteria design decision making. Energy performance, environmental impact, and cost effectiveness are studied over the whole life cycle. The approach is demonstrated with a case study of a warehouse in Amsterdam. Design parameters of interest are the insulation values, construction types, skylight coverage and transpired solar collector coverage. The results indicate that this approach offers design solutions that might not be otherwise identified. The non-case-specific one-time investigation allows objective space of derived performance to be generated dynamically based on even changing information or inputs specified by the users at the time of making the decision. This new design support approach facilitates designers to assess feasibility of any design solution based on their own desired set of performance requirement under different probable scenarios in the future. [ABSTRACT FROM AUTHOR]

Innovative and efficient ways to carry out numerical simulations are worth of investigation to reduce the computational complexity of building models and make it possible to solve complex problems. This paper presents a reduced order model, based on Proper Generalised Decomposition (PGD), to assess 2-dimensional heat and moisture transfer in walls. This model is associated with the multizone model Domus using an indirect coupling method. Both models are co-simulated to perform whole-building hygrothermal simulation, considering 2D transfer in walls. The whole-building model is first validated with data from the IEA Annex 41. Then, a case study is considered taking into account a 2-zones building with an intermediary shared wall modelled in 2 dimensions to illustrate the importance of the technique to analyse the hygrothermal behaviour of the wall. It has been highlighted that the whole model enables to perform more precisely analyses such as mould growth on the internal surface. In addition, important theoretical numerical savings (90%) are observed when compared to the large original model. However, the effective numerical savings are not so important (40%) due to the limitations of the co-simulation method. [ABSTRACT FROM AUTHOR]

With the development of urban construction and building technology, more and more super tall buildings have been built. Due to its huge material and energy assumption, super tall buildings exert great impact on the environment. Embodied carbon is an important tool to measure the environmental impacts of super tall buildings, including the carbon emissions in the process of raw materials processing, structural member manufacturing and transportation. The embodied carbonof super tall buildings could be optimized by integrating the energy dissipation devices in the structural system. Viscoelastic coupling dampers(VCDs) is a kind of efficient energy dissipation devices. By replacing coupling beams in structural configurations, VCDs can effectively increase the level of inherent damping of structures, and thus reduce the wind-induced and earthquake-induced dynamic vibrations. Since the internal forces of structural members subject to lateral loads can also be reduced due to additional damping introduced by VCDs, optimization for the sectional dimension of structural components is made possible, accompanied by reductions to embodied carbon. Embodied carbon based integrated structural design method is introduced in this paper to minimize the embodied carbon of structures by integrating the VCDs. A super tall building located in high seismicity area is presented as an example to illustrate the proposed integrated optimal design method. The design case analysis results for a real super tall building project show that the proposed method is reasonable and can effectively reduce embodied carbon and total cost of super tall buildings. [ABSTRACT FROM AUTHOR]

Chiller sequencing control is an essential function for a multiple-chiller plant that switches on and off chillers in terms of building instantaneous cooing load. It significantly affects both indoor temperature control (hence indoor thermal comfort) and building energy consumption. Various chiller sequencing controls have been developed and implemented in practice, and all of them switch on or off chillers according to a direct or an indirect indicator of the building instantaneous cooling load. Potential uncertainties in the direct or indirect indicator may cause the sequencing control misbehave and deteriorate the control and energy performance of the chiller plant. Until now, there is no any systematic study to investigate those uncertainties. This paper, therefore, proposes such a study. Four typical chiller sequencing controls are considered, including total cooling load-based sequencing control, return water temperature-based sequencing control, bypass flow-based sequencing control, and direct power-based sequencing control. Their uncertainty sources are identified and grouped into different categorizes. In order to facilitate the uncertainty modelling and analysis, all of those uncertainties are shifted to the load indicator of the corresponding sequencing control. Case studies are presented to show that using the proposed method of uncertainty shift and modelling the impacts of the uncertainties on the sequencing controls can be easily identified and analysed. [ABSTRACT FROM AUTHOR]

Underfloor air distribution (UFAD) system, which is a relative new method of providing conditioned air and ventilation to the commercial buildings and data centers, is focused by researchers and designers for its potential advantages of better indoor thermal comfort (ITC) and indoor air quality (IAQ), layout flexibility, reduced life cycle costs, and energy saving. However, the application of UFAD system are still obstructed by the gap in the fundamental understanding of some new elements, such as the cooling load calculation, control of the thermal stratification, and evaluation of energy consumption. This paper reviews the current situation of UFAD technology, and the existing problems in recent researches are summarized. To improve the performance of UFAD system, several possible directions for the further studies are suggested. [ABSTRACT FROM AUTHOR]

This paper will discuss the feasibility of a net zero energy house design targeting for energy balance, financial and environmental sustainability from the initial planning to the final construction for Northern China. A residential house as an experimental objective, which could satisfy an average family's daily needs are in Datong, Shanxi Province in China. Dynamic thermal simulation of the indoor environment, house geometries, solar electric and hot-water collectors, appliances are set in the house. After analysis of the integrated performance of the house, a net zero energy building with the best system configuration predicted by hardware and software simulation are validated. Furthermore, the house is precisely energy monitored and energy controlled after construction. The case study shows that the innovation of a net zero building should be considered as a technological improvement and with a social approval by the occupants of the house. [ABSTRACT FROM AUTHOR]

Insulation is a relevant technical solution for cutting energy consumption in buildings. The aim of this paper is to evaluate the environmental impacts and the consumption of renewable and non-renewable primary energy on the production of conventional thermal insulation materials: extruded and expanded polystyrene, polyurethane, expanded cork agglomerate and expanded clay lightweight aggregates. The comparison per functional unit of the innovative and up-to-date environmental performance of expanded cork and clay with the most common insulation materials used in Europe (the remaining three), and for the environmental categories and life-cycle stages defined in recent European standards, is presented for the first time. These results have been based on site-specific data from companies whose quality was fully characterised, and achieved through a consistent methodology that is fully described, including the modelling of energy processes and a sensitivity analysis of the allocation procedures. These “cradle to gate” results are scientifically sound since they were achieved by following the International standards for Life Cycle Assessment and recent European standards on the environmental evaluation of buildings. [ABSTRACT FROM AUTHOR]

Abstract: One of the primary reasons for the application of cool materials is their energy and associated environmental impact on the built environment. Cool materials are usually applied on the roof of buildings to reduce cooling energy demand. The relative benefits of this reduction depend on the construction of the building, external weather conditions and use of the building. This paper examines the impact from the application of a reflective paint on a flat roof in a naturally ventilated office building in the area of London, UK where the climate is moderate with high heating demand by buildings. The environmental conditions (internal/external air and surface temperatures) of the building were monitored before and after the application of the cool roof during the summer. It was found that internal temperatures were reduced after the application of the cool roof. The building was modelled using TRNSYS and the model was calibrated successfully using the measurements. A parametric analysis was carried out by varying the reflectivity and insulation of the roof and ventilation rate; the heating and cooling demand for a year was calculated using the Summer Design Year for London as the weather file. It was found that cooling demand is significantly reduced, heating demand is increased and the total energy savings vary between 1 and 8.5% relative to an albedo of 0.1 for the same conditions. In free floating (naturally ventilated) buildings summer comfort is improved but there is a penalty of increased heating energy during the winter. Thermal comfort can be improved by an average of 2.5°C (operative temperature difference for a change of 0.5 in albedo) but heating demand could be increased by 10% for a ventilation rate of 2 air changes per hour. The results indicate that in the case of temperate climates the type, operation and thermal characteristics of the building should be considered carefully to determine potential benefits of the application of cool roof technology. For the examined case-study, it was found that a roof reflectivity of 0.6–0.7 is the optimum value to achieve energy savings in a cooled office, improve summer internal thermal conditions in a non-cooled office (albeit with some heating energy penalty). It indicates that it is a suitable strategy for refurbishment of existing offices to improve energy efficiency or internal environmental conditions in the summer and should be considered in the design of new offices together with other passive energy efficient strategies. [Copyright &y& Elsevier]

Abstract: The world faces a number of environmental issues. Developments (especially technological) in our society are still of highly extensive nature and the forthcoming process of globalization significantly affects the state of the environment. There is also a slight increase in population, uncontrolled extraction of raw materials for production of materials, energy and urbanization of the environment. At the same time the amount of harmful emissions and wastes increase. Mineral resources are considerably limited. As well as limited resources to feed a growing population (problems of drinking water and food) limited resources and materials needed for construction of buildings, infrastructure development and industry provision to further ensure the welfare of people. It follows the need for change of approach in area of civil engineering. Concrete is the most used building material in the world, but unfortunately it also leaves a major carbon dioxide emission. In building industry, it includes cutting back carbon dioxide emissions by using less energy consumptive materials - that is, by maximizing use of waste products. Many articles have been written on how this industry can contribute. This can occur in a number of ways and one of them is use substitutes for Portland cement with waste products such as fly ash, ground-granulated blast furnace slag cement, rice hull ash, silica fume, pozzolans of all types, and ground limestone, in the process of concrete production. This paper is focused on the possibility of using fly ash to replace cement in concrete pavement. Mechanical properties, chemical resistance, freezing and thawing of fly ash concrete were measured and compared with the reference specimen (C 30/37), which met the requirements of STN 73 6123. Besides, the economic assessment of costs of both concretes (with/without fly ash) was made. Finally, environmental benefits of brown coal fly ash utilization in the area of Slovak road engineering based on its life cycle analysis are also presented. [Copyright &y& Elsevier]

Abstract: Energy and comfort management is the major task for a building automation system. As a trend of next-generation''s commercial buildings, intelligent buildings are capable of facilitating intelligent control of the building to fulfill occupants’ needs. Since occupants’ behaviors have a direct impact on the system performance, the building should be able to interact with occupants by responding to their requests and obtaining feedbacks based on their behaviors. In this paper, a multi-agent based intelligent control system is developed for achieving effective energy and comfort management in a building environment. The developed multi-agent system turns out to be capable of facilitating the building to interact with its occupants for realizing user-centered control of buildings. [Copyright &y& Elsevier]

Abstract: Cool roofs are an emerging technique with a recent growing interest worldwide. The aim of the present paper is to present the application of cool roofs’ technology in a laboratory building located in Iraklion, Crete, Greece. The building is monitored towards its energy performance and indoor environment before and after the implementation of the cool roof technology. The specific case study is intended as a shining example of the cool roof capabilities in improving the thermal conditions in non-air conditioned and in reducing the energy consumption in air conditioned buildings. [Copyright &y& Elsevier]

Abstract: This paper presents a new method for selecting the energy reference year, which may be used for many applications, such as the energy performance of buildings, the simulation of active or passive solar energy systems, HVAC system performance or indoor climate analyses. The EN ISO 15927-4 method was modified by using monthly dependent weighting factors for the main climatic parameters in the calculation of heating and cooling energy demand in buildings. We used data from the cold Finnish boreal climate to demonstrate the method. In a cold boreal climate, during the summer temperature and solar radiation have a similar influence on heating and cooling energy demand, whereas air humidity and wind speed have a minor effect. The principle for determining the weighting factors and modified method for the selection of the energy reference year can also be used for other climatic zones. The weighting factors determined in this study can be used for other countries in a cold climatic area. [Copyright &y& Elsevier]

The occupants’ health, comfort, and productivity are important objectives for green building design and operation. However, occupant behavior also has “passive” impact on the building indoor environment by generating heat, CO 2 , and other “disturbances”. This study develops an “indirect” practical data mining approach using office appliance power consumption data to learn the occupant “passive” behavior. The method is tested in a medium office building. The average percentage of correctly classified individual behavior instances is 90.29%. The average correlation coefficient between the predicted group schedule and the ground truth is 0.94. The experimental result also shows a fairly consistent group occupancy schedule, while capturing the diversified individual behavior in using office appliances. Compared to the occupancy schedule used in the Department of Energy prototype medium office building models, the learned schedule has a 36.67–50.53% lower occupancy rate for different weekdays. The heating, ventilation, and air conditioning (HVAC) energy consumption impact of this discrepancy is investigated by simulating the prototype EnergyPlus models across 17 different climate zones. The simulation result shows that the occupancy schedules’ impact on the building HVAC energy consumption has large variations for the buildings under different climate conditions. [ABSTRACT FROM AUTHOR]