Search

Abstract: As an important part of economical society, colleges and universities have been shouldering the important task of education, science research and social service. In this paper, a detailed investigation in the form of questionnaire was carried out for the energy consumption of colleges and universities in Guangdong Province, including electricity, water, gas and cooling energy consumption from 2006 to 2010. The energy meter reading modes, energy conversation investment amount and energy-efficiency retrofit work were also reported and analyzed. Furthermore, as can be concluded from the survey, there exists great difference in per unit energy consumption between different types of universities classified by schools’ discipline, nature and level, which would be taken into account when the energy consumption evaluation indexes system is established. Although energy-saving measures at Guangdong's colleges and universities bear fruit, Guangdong's colleges and universities still have great potential of energy conservation and emission reduction by Conservation-oriented campus construction, and the government should increase funding and improve economic policy to encourage and support energy saving for colleges and universities. [Copyright &y& Elsevier]

• The study presents the comparison between planned and realized energy savings. • The actual energy consumption is often much higher than the calculating. • The insufficient funds for investment lead the project astray. • Only through integral design with consistent realization, the expected savings can be achieved. • A regulatory framework that integrates actual energy consumption is suggested. Improvements in the energetic efficiency of a building bear the greatest potential in terms of saving energy and reducing the emission of toxic gases. One of the most efficient energetic efficiency improvement measures is replacement of old coal boilers for central heating with new pellet boilers. The study presents the comparison between planned savings before replacement of boilers and realized savings after their replacement. The theoretical approach was based on the analysis of the energetic characteristics of this object in the investment planning stage by applying mathematical modeling. It was published as a part of the research paper "Revitalization of architectural objects by means of energy efficiency improvement: An economic case analysis" [1]. However, the decisions made in the phase of boilers replacement were different compared to the planned investment. Between theory and practice, this paper analyzes the difference between parameters envisaged in precalculations and those achieved later. Rational energy consumption and environmental protection are the crucial elements of energy policie, as well as the key elements of national growth and development. A great contribution to solving this crucial development problem would be made by accurate investment planning and its consistent implementation, thus establishing harmony between theory and practice. [ABSTRACT FROM AUTHOR]

The thermal properties of building envelopes have a major effect on energy consumption and indoor comfort, which is even more significant for glass buildings. The current solutions for mitigating this is either improving U-value and solar heat gain coefficient (SHGC) with additional layers, utilizing shading device or changing the transparency of the glazing system with adjustable properties. These solutions address the problem of energy consumption to a certain extent but cannot effectively manage and take advantage of the solar radiation effectively. Moreover, shading solutions obstruct the view to the outside and have negative impact on daylighting. This paper introduces Water-filled glass (WFG) technology, a transparent glazing system that utilizes water infill to improve thermal performance of the building envelope. The impact of WFG on cooling and heating energy demand is evaluated by studying different glazing configurations for WFG in different climates. Besides, the overall performance of WFG is compared with conventional double glazing with Low-E as base-case (with and without shading). The significance of this evaluation is that a comprehensive climate-based assessment considering absorption and insulation-based options for WFG is presented here for the first time: the paper evaluates different options of glazing system in combination with active systems in building via advance dynamic simulation over a typical year for all major Köppen-Geiger climates (13 cities). Additionally, as a novel approach, the simulation results presented here identify climates where improving SHGC is more ideal for thermal performance than improving U-value even if it occurs by compromising the latter and distinguishes absorption-based and insulation-based scenarios respectively. The results show that absorption-based energy model is a viable option, which results in energy savings between 3 and 84% in value of US$0.99-24.25/m².a depending on climate. The discussion includes simulation and comparison with identical spaces using standard technology that follows the local building code and conventions. The climate-based evaluation of water-filled glass can improve energy consumption of buildings and offer a sustainable strategy for glass envelopes by absorbing and reusing heat where transparency becomes an asset instead of being a liability. [ABSTRACT FROM AUTHOR]

• This method integrates uncertainty analysis and cluster analysis methods. • Proposed novel zoning indicators are statistically significant. • Moves from traditional weather-based approaches to a performance-based approach. • Robust tool to tackle complex relation between climate and building energy efficiency. • Provide evidence for the rationality of decision making in energy policy. Climatic zoning is an important tool in building energy policy and regulations, smaller and more homogeneous climate zones could help enhance the rationality of energy policymaking. In most countries, climate zoning is based on simplified climate models, and it is difficult to accurately represent the energy demand characteristics of buildings. Therefore, this paper proposes a novel climate subdivision method that tackles the complex relations between climate and building energy-efficient, which move from traditional weather-based approaches to a performance-based approach. Integrate the uncertainty analysis method and the building dynamic performance simulation to extract a novel statistically significant index as the basis for classification. The K -means clustering method and discriminant analysis method are used to obtain and verify the clustering results, respectively. Furthermore, the comparison with clustering results based on degree days confirms the superiority of the new method proposed in this paper in identifying building energy demand. The method is applied to the cold climate zone of China as a showcase. The results show significant differences in building energy demand and the order of key features affecting building performance between each region in the climatic zones. The zone can be further sub-divided into four groups considering the climate factor and building feature uncertainty, and clustering results have been verified by several evaluation indicators. [ABSTRACT FROM AUTHOR]

• The energy performance of chilled water systems in a high-rise office building was examined. • Key indices were put forward to analyze the influence factors and their characteristics. • Systematic optimization methods were put forward from the aspects of external factors, internal factors and synergies between them. • Considerable energy saving effects were achieved on the premise of ensuring the indoor cooling demand. The chilled water system is the major component of HVAC systems, and it consumes a large amount of energy and has significant influence on the cooling effect. To save energy and provide a comfortable indoor environment, the energy performance of the chilled water system should be analyzed and improved. This paper introduces a systematic optimization process of the chilled water system in a high-rise office building. First, the influencing factors and their characteristics are summarized and analyzed, and the results show that higher temperature difference, energy efficiency of typical devices, and lower terminal resistance contribute to the improvement in energy performance. Then, based on the analysis, a systematic optimization method is put forward considering the external factors, internal factors, and synergies between them. Finally, an optimization of the studied building is conducted, from terminals to the chiller plant, and considerable energy saving effects are achieved on the premise of ensuring the indoor cooling demand. [ABSTRACT FROM AUTHOR]

• HVAC system stock is heterogeneous and changes over time. • A HVAC stock modeling and an archetype building energy modeling were integrated. • Disregard of the heterogeneity and its change can cause error in energy modeling. • Energy reduction by technological innovation relies on the share of the HVAC stock. Urban building energy model (UBEM) is an important tool in coping with energy issues of building sector. This paper focuses on an issue that the stock of heating, ventilation, and air-conditioning (HVAC) systems has been oversimplified in UBEM without considering its heterogeneity. It has been observed that this oversimplification may incur a significant error in the result. To address this issue, this paper proposes a framework that integrates a logistic regression based HVAC system stock modeling method and the bottom-up type engineering modeling method using building archetypes considering HVAC system configurations. A case study with Japanese office building stock revealed that (1) the disregard of the heterogeneity resulted in an error of 15% in the annual primary energy consumption, (2) the historical change in the HVAC system stock could decrease the consumption up to 5%, and (3) its composition has a significant influence on the energy saving due to energy efficiency increase in heat source machines used in HVAC systems. The presented method would contribute not only to improving the reliability of UBEM but also to providing an analytical capability of considering energy efficiency technologies related to HVAC systems along with the alternation of technology selection in the building stock. [ABSTRACT FROM AUTHOR]

This paper develops a new process for identifying the lowest cost package of energy efficiency measures (EEM) and hybrid energy system configuration for off-grid homes. Hybrid energy systems, which combine two or more types of energy technologies, often require significant capital expenditure, however, the cost can be reduced by applying EEM to the house to decrease energy demand. The method proposed here, termed Combined Optimization Process (COP), was tested on an off-grid hypothetical case and incorporates an iterative assessment of a building energy and efficiency optimization tool (BEopt) and a hybrid system optimization tool (HOMER). The COP results were compared with the base case where no efficiency measures were applied, and also with a standard process, which involved a selection of best-practice efficiency measures. The COP method yielded net present cost savings of 10% less than the base case, and 5% less than the standard process. The COP method developed in this paper is applicable for existing houses converting to off-grid status as well as for the design stage of off-grid houses. [ABSTRACT FROM AUTHOR]

• New building development projects underperform often. • Underperformance leads to increased energy consumption and CO 2 emissions in building operation. • The paper links building project development and building operational performance. • Two simulation methods are combined in a multi methodology framework in the paper. • The paper explores the implications of project partner collaboration for operational building performance in the case of a recent building project. The "performance gap" in the United Kingdom construction industry is a persistent problem as new building development projects underperform more often than not. The "performance gap" is partially attributed to the number of stages involved in building project development and the coordination difficulties of partners with different incentives. The project outcome is important for energy consumption, carbon emissions and occupant well-being. Thus, it is important to study the project management process in terms of the standard time, cost and quality parameters, but also in terms of project partner incentives and coordination, and the subsequent energy performance and resultant indoor environmental conditions. A system dynamics model of project management processes is developed to explore the implications of partner coordination for building quality. The system dynamics model is coupled to a building performance simulation model to explore building energy consumption and Indoor Environmental Quality, and apply this on a recent building project case study. Results show that greater project partner alignment can reduce annual energy consumption up to 12% and CO 2 emissions up to 37%, with greater emphasis in the design stage of the project subject to resource availability. The trade-offs involved on value appropriation are considered and discussion of results points to possible ways for improvement. [ABSTRACT FROM AUTHOR]

• Performance of a new cooling pad (cellulose paper, bee-hive) was studied based on energy-exergy analysis. • Parametric study of the effect of operating and design conditions was conducted. • Empirical correlations for performance parameters were predicted. • Optimum operating and design conditions were investigated and obtained. • 84% saturation efficiency and 18 °C and 8 Pa temperature and pressure drop were obtained at optimum conditions. In this paper a comprehensive experimental parametric study on the performance of a new evaporative cooling pad type made of cellulose papers in bee-hive structure is presented. Four different pad sizes of face area 0.335 × 0.390 m2 and thicknesses 35, 70, 105, and 140 mm are examined. The tests are carried out in a wind tunnel adapted with the evaporative cooling system. Experiments are conducted to evaluate the cooling pad performance parameters: air temperature drop, air humidity ratio raise, cooling capacity, water evaporation rate, saturation efficiency, pressure drop, energy efficiency, energy efficiency ratio, exergy efficiency and overall exergy efficiency. The effects of the cooling pad thickness and the operating conditions including air velocity, inlet air temperature, water flow rate, water temperature and cooling pad thickness on the performance parameters are investigated. The results show that, the saturation efficiency, exergy efficiency and overall exergy efficiency of the proposed pad enhance with increasing the pad thickness and water flow rate and their highest obtained values are 84%, 92% and 74%, respectively. The maximum pressure drop, temperature drop and cooling capacity obtained for this pad are 46 Pa, 18°C and 6.26 kW, respectively. Moreover, the highest energy efficiency ratio is 281 obtained at 2 m/s air velocity. Finally, new dimensionless experimental correlations for predicting the system performance parameters in terms of various operating conditions and system size are presented. [ABSTRACT FROM AUTHOR]

• A POE-integrated simulation method is proposed to address energy occupant behavior. • Opening windows and operating AC were found to co-exist which affects simulation accuracy. • The new method improves energy simulation accuracy by 14% for domestic areas. • The method improves energy simulation accuracy by 16% for total building areas. Occupant behavior plays a critical role in building energy consumption, particularly in residential buildings. However, occupant behavior is complicated and varies significantly from case to case. Also, energy modeling of high-rise buildings is far less explored than that of low- or medium-rise buildings. This paper aims to improve accuracy in building energy simulation by utilizing Post Occupancy Evaluation (POE) data to calibrate energy model. Drawing on a review of the literature of occupant behavior and building energy modeling, the paper provides a calibration method of integrating POE data into an energy model, which is demonstrated using a real-life typical 40-storey residential building in Hong Kong. The developed method addresses seven updated input parameters, namely, schedule, devices, air-conditioners, windows, lights, domestic hot water, and cooking. By comparing the two energy modeling processes, i.e. with and without POE input, and their resultant estimated energy consumption, the paper quantifies the impact of occupant behavior on building energy consumption. Annual metered data together with energy bills obtained from the POE were utilized to validate the models. The results show that the use of the developed POE-integrated method helped to improve accuracy in energy consumption prediction by 14% for the total building floor area and by 16% for the total residential area. From examining the impacts of the seven input parameters, the paper reveals the key energy use sensitive occupant behaviors within high-rise residential buildings in Hong Kong. These include: the number of residents in each unit; adoption of window type and split type of air-conditioners; window and air condition operation modes; cooking time on weekdays and weekends; and time spent on hot water showering. The developed method can assist building designers and services engineers to estimate building energy use more accurately and provides a scenario analysis tool for clients and facility managers to develop effective energy conservation strategies. [ABSTRACT FROM AUTHOR]

Interest in urban building energy modeling as a tool to evaluate effective management of urban building energy and carbon reduction policies is increasing. Since it takes a lot of time to model all buildings in the city with the lack of information about buildings, archetypes have been used. However, the deterministic method using archetypes does not reflect uncertainty with the disadvantage of not presenting design alternatives. To overcome such problems, we proposed an urban building energy modeling method using a stochastic-deterministic-coupled approach. In this paper, the identifiability of unknown parameters in a building stock was verified by analyzing the effect of the meta-model accuracy on the estimation of unknown parameters in the proposed urban building energy model. In addition, the possibility of using energy conservation measure analysis of the proposed model was evaluated. As a result, the posterior distribution of unknown input parameters was distorted when using the meta-model instead of the original building energy model in Bayesian calibration for building stock. However, the distorted posterior distribution could evaluate the effect of energy conservation measures within 0.71% errors. [ABSTRACT FROM AUTHOR]

• Sunken courtyards reduce the household energy consumption of farmers nowadays. • Policy guidance and building conditions are the main factors that affect decision-making of living modes. • Village collective and individual decisions affect the energy consumption level of the whole village system. • Vernacular architecture is the local solution of rural energy-efficient development. Vernacular architecture has been widely concerned in recent years because of its energy-efficient and environmental adaptability characteristics, and is considered as a potential method to reduce rural energy consumption and an important cultural heritage. However, under the rural modernization and urbanization, vernacular architecture is in danger of disappearing. This paper focuses on the sunken courtyard, a typical vernacular architecture that utilizes underground space, carries out field investigation and questionnaire survey in villages of Shanzhou District, China. It is found that local residents adopt a variety of spatial utilization modes for sunken courtyards, and the structural equation model is further applied to analyse the decision-making process of farmers. The result is as follows: First, the utilization of sunken courtyards still reduces the household energy consumption; Second, policy guidance (weight coefficient is 0.57) and objective building conditions (weight coefficient is 0.25) are the main factors that affect farmers' decision-making; Third, village collective and individual decisions affect the energy consumption level of the whole village system. Finally, the formulation of rural development policies should fully consider the relationship between residents, buildings and village systems, so as to form unique local solutions. This study provides insights for the development of future architectural heritage conservation and rural renewal strategies. [ABSTRACT FROM AUTHOR]

• End-use of electricity consumption in residential buildings in Gulf Cooperation Council countries was presented. • Discrepancies in certain indicators have been observed by the end-use of electricity consumption. • Improving the efficiency of air conditioners and thermal insulation of the walls are the best measures to conserve electricity in residential buildings. • The results can be used in areas with a similar climate, living standard, buildings types, and the inhabitants' behavior. Energy conservation and improvement in energy efficiency yield multiple technical, economic, environmental, and social benefits and realize comfort and sustainability of residential buildings (RBs). This review paper presents the end-use of electricity consumption in RBs and the results of economic analysis. In addition, a description and discussion of studies on energy conservation measures, Net Zero Energy Building, and renewable energy in RBs are discussed. The percentage of end-used energy consumption for different purposes obtained in many studies are often not consistent. Moreover, discrepancies in certain indicators have been observed, necessitating the need to clarify the factors in the consumption of electricity in RBs. Further, a few studies used the term energy consumption in buildings (total or electrical); however, specifying the type of buildings to identify and use the necessary indicators of energy consumption in each type of building are desirable. Furthermore, most studies emphasized improving the efficiency of air conditioners and thermal insulation of the walls as these are the best measures to conserve electricity. [ABSTRACT FROM AUTHOR]

Human influence is recognized as a major source of discrepancy between predicted and actual building energy use and has been a subject of extensive analysis for many years now. However, the impact that different users can bring to the actual performance of a building has not yet been studied in depth. This paper aims to contribute to this understudied dimension of the performance gap by providing a quantitative assessment of the impact of different users in residential heating consumption and indoor environmental conditions. For this purpose, heating energy consumption profiles for real users along with their corresponding thermostat settings were modeled in a building simulation model of a single dwelling thus allowing the study of the user factor in isolation. Remarkable differences were found in the resulting heating energy consumption and in the percentage of time that thermal comfort conditions defined by building regulations and standards were met for the different user scenarios. Results also demonstrate how the more complicated and varying the heating practices of a user are the more varying and unpredictable the impacts on heating consumption and comfort are. Overall, findings add to the growing body of literature that questions the standardized heating profiles and temperature settings used in energy simulation for residential buildings. [ABSTRACT FROM AUTHOR]

[Display omitted] The rapid development of urbanization has created high demand for central heating systems. This trend has led to an increase in energy consumption for central heating, which has made China's energy-saving transformation extremely difficult. However, the channel by which urbanization impacts and the future trends of energy consumption for central heating are still unclear. Therefore, this study employs the Logarithmic Mean Divisia Index (LMDI) method to decompose the effect of urbanization on changes in energy consumption for central heating during 2001–2019 in China. We investigate the contribution of urbanization from demographic, economic and spatial perspectives. Additionally, a scenario analysis is used to explore trends in energy consumption for central heating in different projected urbanization scenarios. The results show that urbanization has a positive impact on energy consumption for central heating, particularly in underdeveloped regions. Demographic urbanization has the strongest positive effect on energy consumption for central heating, followed by spatial urbanization and then economic urbanization. Compared with the expansion of area and economic development, population agglomeration will bring more energy consumption for central heating. The forecasting results indicate that energy consumption for central heating will reach 176–189 Mtce in 2030, which is approximately 1.4 times the current level. This work quantifies the energy consumption for central heating in the future under urbanization. The policy recommendations given at the end of the paper will provide a reference for the formulation of energy consumption for central heating. [ABSTRACT FROM AUTHOR]

• A comprehensive analysis of data from commercial buildings in United States to identify operational problems and opportunities. • These opportunities were not strongly correlated with building vintage, size, or building type, but were reflective of how the buildings are operated. • This analysis showed that opportunities to improve building operations exist in almost every building. • There was wide variation in whole building energy savings, ranging from 0 to 50% and 0 to 18 $/m2 with median percent annual whole building savings of 12% and median normalized annual cost savings of $1.75/m2. In the United States, as much as 30% of the 19 EJ that commercial buildings consume is considered excess. Much of the excess energy is due to the inability to manage building operations efficiently. Because almost 20% of the total primary energy consumption is associated with commercial buildings, significant energy reductions in this sector are needed to mitigate climate change. Therefore, many cities and states are mandating periodic "tune-ups" of these buildings to eliminate excess energy consumption. Although the benefits of tune-ups and retro -commissioning are clear, focusing these mandates to look for specific opportunities has been a challenge because of the lack of studies that document the prevalence of opportunities. Therefore, we analyzed building automation system data from 151 buildings across the United States to document common operational problems and opportunities to improve building operations. This analysis showed that opportunities to improve building operations exist in almost every building. These opportunities were not strongly correlated with building vintage or size, but were reflective of how the buildings are operated. The prevalence of the top 20 opportunities ranged between 74% and 23%, with 40% of these associated with air-handling units. The rest of the opportunities are associated with schedules, chilled and hot-water distribution, and zone controls. Of the 151 buildings, 69 of them implemented corrective actions of some or all opportunities that were identified. Implementation varied across the Re-tuning categories, with 60% for schedule opportunities, 50% for zone opportunities, over 40% for the air-handling unit and hot-water opportunities, and 35% of the chilled-water opportunities. There was wide variation in whole building energy savings, ranging from 0 to 50% and 0 to 18 $/m2 with median percent annual whole building savings of 12% and median normalized annual cost savings of $1.75/m2. In addition to documenting these key findings, the paper provides a list of opportunities that can be automatically and continuously identified and corrected and offers a list of those opportunities that should be the focus of the mandates. [ABSTRACT FROM AUTHOR]

[Display omitted] • Transients are considered in the Optimal Chiller Loading/Sequencing problem. • Decision variables are extended with respect to previous OCL/OCS approaches. • SPSA is deployed and hyper-parameters tuning is discussed. Scheduling and loading of chillers in a multi-chiller plant is considered. A new framework is introduced considering an extended set of independent variables for the optimization problem of energy consumption. In this way the number of decision variables is increased, providing extra degrees of freedom to optimize cooling plant operation. The dynamic effects due to transients arising from switching on and off of units are usually not considered in the literature dealing with Optimal Chiller Loading/Sequencing which is restricted to the static case. In this paper, these effects are treated in a way that results in a manageable optimization problem. A Simultaneous Perturbation Stochastic Approximation solution is deployed for the problem and the proposed method is compared with a similar but static approach showing the benefits in terms of reduced energy consumption. [ABSTRACT FROM AUTHOR]

• A framework for optimizing the design of underground spaces is established. • The relationship between underground space and travel CO2 emissions is clarified. • Factors affecting underground space travel are quantified through multi-source data. The utilization of underground space plays a vital role in saving land, alleviating traffic pressure, and improving the utilization of resources. The combination of walking and metro instead of cars is an effective way to reduce energy consumption and CO2 emissions. However, transfer inconvenience, poor accessibility, lack of vitality, and other phenomena in the underground hinder this low-carbon transportation utilization. This paper aims to improve travel quality and efficiency by optimizing underground space design to reduce CO2 emissions and raise energy efficiency. Taking a typical underground space in Nanjing as an example, multi-source methods such as field measurement, POI, and space syntax are used to quantify the factors affecting underground space travel. Correlations between each factor and the density of passenger flow distribution are discussed. The results show that catering and shopping are the most correlated factors of the pedestrian flow distribution on weekdays and weekends, respectively. Through simulation, the optimized design can increase the passenger flow and reduce CO2 by 277.9 g/Km and 119.1 g/Km per minute on weekdays and weekends, respectively. The design is consistent with the result of 219 questionnaires. This research method has positive significance for developing underground space in other Chinese cities under low carbon background. [ABSTRACT FROM AUTHOR]

• Public grants for energy renovation of buildings induce economic benefits. • Renovations stimulate local construction, industry, trade and transport firms. • Climate conditions and regional economic structure determine intensity of benefits. • Benefits are the highest in regions producing energy-efficient building materials. This paper explores whether the policy of mitigating climate change through energy-efficient retrofitting supports more balanced development or increases regional disparities. The issue is explored through the estimation of the socioeconomic effects of energy-efficient renovation across Croatian regions. The regional input–output model is applied to identify direct, indirect, and induced effects of building retrofit investments on gross value added and employment. In the Croatian case, over three-quarters of the total economic effects of energy-efficient retrofitting is distributed to the more developed region of Continental Croatia. Economic activity in the Adriatic region is strongly dependent on tourism with insufficient local production of the manufacturing products required in energy renovation projects, and a certain proportion of spillover effect of the investment is transferred to Continental Croatia. The positive economic effects induced by retrofit investments are most present in construction, manufacturing, trade, and transport. Results suggest that climatic conditions and regional economic specialisation have an impact on the dispersion of the economic effects of retrofit measures in different regions. [ABSTRACT FROM AUTHOR]

• The degree of influence of residential cluster layout factors on building heating energy consumption levels in cold regions of China. • Provides an idea of residential layout optimization and design based on the energy saving objectives of residential clusters, translating quantitative indicators such as wind environment into residential layout form design problems. • Energy simulation-based residential planning and layout design method is used to quantify the relationship between residential cluster design factors and energy efficiency in Jinan, resulting in optimal design parameters for residential planning factors in Jinan. • The study of building heating energy consumption in a city in a cold region of China, with a methodology that can be used in countries or cities with similar climate characteristics. Residential heating energy consumption in China accounts for about 34% of the total building operation energy consumption in the country. The layout pattern of residential clusters is one of the most critical factors affecting building heating energy consumption, yet few scholars have studied the layout of residential clusters in a quantitative way. This paper takes Jinan, a typical city in cold region IIB of China, as an example, to quantify and analyse the residential layout parameters related to heating energy consumption: group layout, building orientation and building spacing; ECOTECT and HTB2 are used to model and simulate the energy consumption of the three types of layout residential groups selected for the study, and the relationship between residential group layout parameters and residential heating energy consumption is analysed based on multiple linear regression analysis. The relationship between residential group layout parameters and residential heating energy consumption was analysed based on multiple linear regression analysis. The study shows that, on the premise of ensuring the same building density, the group layout has the greatest influence on the building energy consumption, and the courtyard layout has lower heating energy consumption compared to the row and staggered layout; on this basis, the influence of building orientation and building spacing on heating energy consumption is discussed. The study shows that increasing the spacing between buildings to meet the daylight spacing will reduce energy consumption by 4% and that a 15° shift to the west will reduce energy consumption by 5%. This result confirms the importance of cluster layout in terms of heating energy consumption and urban energy efficiency in cities in cold regions. [ABSTRACT FROM AUTHOR]

Today, about 35% of global energy consumption and related carbon dioxide emissions are caused by the construction sector. This paper evaluates and compares the life cycle energy consumption (LCEC) and carbon dioxide emissions (LCCE) of a heritage building (BT1) constructed in 1875, a new building (BT2) constructed with modern constructional elements with similar plans of the heritage building and the heritage building after the restoration and refurbishment (BT3) by using real data from the construction site of a real project in Gaziantep, Turkey. It is calculated that, the operational phase was dominant over the buildings lifespan and BT1 has the highest operational energy consumption. LCEC and LCCE of the BT1, BT2 and BT3 are calculated to be 102.63, 70.13, 78.07 GJ/m2, and 14.18, 9.75 and 10.06 tons of CO 2 per m2 (tCO 2 /m2), respectively. With current techniques and methodologies the refurbishment and restoration of the heritage building increases the embodied energy (EE) by 56.6%. Selection of appropriate construction materials for refurbishment of heritage buildings is an important procedure that prevents excessive increment of EE and related emissions. Sustainable structural restoration of heritage buildings should be performed by using appropriate methodologies observing the conservation principles of history, energy and environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The application technologies of advanced inter-pane media in multi-glazing windows are introduced. • Assessment methods including experimental methods and numerical models are introduced. • The performance of different application technologies is summarized. • A comparison of the energy saving potentials of different advanced inter-pane media under different climates is conducted. Multi-glazing (including double-glazing) windows have attracted increasing attention in recent years due to their effective performance in saving energy consumption. The common medium between two glass panes is stationary air or inert gas and it could be treated as an extra component in multi-glazing windows. This opens possibilities to apply different fluids and promising filling materials, including airflows, flowing liquids, aerogels and phase change materials (PCMs), as advanced inter-pane media to further enhance window performance and match different requirements in different climates. To facilitate the application and further development of such application technologies, this paper aims to provide a comprehensive review mainly including: application technologies, performance assessment methods and indicators, and performance analysis of different application technologies. Also, a comparison of the energy saving potentials of different advanced inter-pane mediums in different climates is provided. In addition, suggestions for future works are given based on current progress. [ABSTRACT FROM AUTHOR]

In view of advancing global warming, climate change adaptation and mitigation measures for buildings are becoming increasingly important. The following article discusses the question of whether current urban planning principles still provide a suitable framework for this purpose. Therefore, the aim of this paper is to identify and quantify the main parameters of the urban planning framework regarding energy demand and energy generation of buildings. In a novel, holistic approach, passive design measures were evaluated in a joint analysis based on a case study in the city of Vienna (Austria) with respect to their impact on heating and cooling energy demand, overheating potential, daylight availability, and solar potential of new buildings. The results show that by improving the thermal insulation of the building envelope, the importance of a high compactness of the buildings to lower the heating energy demand is decreased. In addition, moderate compactness can help reduce the energy demand for space cooling and artificial lighting and increase the solar potential of the buildings. Accordingly, the results question the dogma of a high degree of compactness that still exists to some extent and indicate that changing climatic conditions also require new approaches in the urban planning process. [ABSTRACT FROM AUTHOR]

• Time Use Survey data used profiles of occupancy and energy behaviours. • Patterns were time-dependent and affected by household size. • Behaviour patterns were aggregated to produce hourly energy demand profiles. Occupants' interactions with building components determine the timing and magnitude of energy demand. Therefore a more realistic representation of energy-related occupant behaviours in energy simulations will enhance the accuracy of predicted building energy demand. The aim of this paper was to assess occupancy and behavioural patterns in Australian households based on a detailed time use survey, which collected daily activities from 6,902 persons in 3,626 households. Profiles of occupancy state and energy-related activities were analysed for different seasons, day of the week, and household compositions. The activity sequences were further aggregated to reproduce the total time use for the activities and occupancy states. The results showed that occupancy and the timing of energy related activities were time dependent and were also affected by season, day of week, and household composition. The outcomes can be used as input to simulation tools where realistic occupant behaviour should be taken into account. [ABSTRACT FROM AUTHOR]

• A framework for retrofitting existing houses to NZEBs is proposed. • The framework includes renewable system design, building envelope improvement and energy system retrofit. • The framework practicability and reliability were demonstrated in a real building retrofit. • Energy consumptions before and after retrofit were presented and compared. Nearly zero energy building is a promising solution for tackling the conflict between the reducing fossil fuel reserves and the ever-increasing energy demand. Initiatives and goals for nearly zero energy buildings have been announced in different countries, as well as a series of strategies and incentives for advocating renewable energy applications. Within this context, homeowners' energy awareness has been strengthened and more and more of them are willing to invest on energy efficiency improvement and renewable energy application. However, there is no clear method or procedure for common practitioners to follow in the practice of energy retrofit of existing buildings, more specifically existing houses. This paper fills this pressing research gap by developing a framework for retrofitting existing houses to nearly zero energy buildings. The developed framework is then implemented on a real house in Beijing to demonstrate its reliability and practicability. The innovations of this study lie in the full consideration of the actual conditions of existing houses as well as the practicability of the framework, and for the first time, the detailed energy performance measurements of a real-life house from its original inefficient condition to after being retrofitted to a nearly zero energy building are presented. The framework can be easily extended to applications of other renewables and serve as a guideline for the wide common practitioners in their real building renovation practices. [ABSTRACT FROM AUTHOR]

With growing trends towards smaller-scale, low carbon energy systems such as microgrids and later generation district heating, coupled with the increased use of building simulation in bottom-up stock modelling, there is increasing interest in being able to automatically generate multiple, high-resolution profiles of both occupancy and occupancy-dependent household demand. This has resulted in the emergence of a range of tools capable of producing time-varying occupancy and demand profiles that capture many of the characteristics evident in real-world data. However, as a result of limited data availability, these tools have typically been calibrated using composite data from multiple individuals or households. This results in the production of profiles which whilst statistically faithful to the average characteristics of the underpinning data, fail to capture the variance seen from household-to-household in the real world. This paper attempts to address this shortcoming, developing and testing a new method within an existing model structure for the production of occupancy and linked demand data using a probabilistic model that is representative of the overall population from which it is derived, but which has an improved ability to generate specific outputs that better match the behaviour of specific households. The new approach utilises previously established occupancy and demand modelling methods, along with the composite population-based calibration data used within the models. However, the temporal predictive basis of the models has been manipulated to account for individual behaviours whilst retaining the overall statistical characteristics of the source data. This was achieved by adapting the Markov chain timing basis for previously developed models and factoring the probability values. A linked electrical demand model has also been adapted by manipulation of the relative timing of use of different appliances and demands to account for differences between individual and average behaviours. The described approach has the benefit of not requiring any additional calibration data, which for both occupancy and energy demand is often scarce. The predictions of the improved model and previous version are compared to real occupancy and demand data, indicating that the alterations enable significantly more diverse profiles to be generated, whilst still being representative of the supporting data. [ABSTRACT FROM AUTHOR]

An effective and accurate building energy consumption prediction model is an important means to effectively use building management systems and improve energy efficiency. To cope with the development and changes in digital data, data-driven models, especially deep learning models, have been applied for the prediction of energy consumption and have achieved good accuracy. However, as a deep learning model that can process high-dimensional data, the model often lacks interpretability, which limits the further application and promotion of the model. This paper proposes three interpretable encoder and decoder models based on long short-term memory (LSTM) and self-attention. Attention based on hidden layer states and feature-based attention improves the interpretability of the deep learning models. A case study of one office building is discussed to demonstrate the proposed method and models. Firstly, the addition in future real weather information yields only a 0.54% improvement in the MAPE. The visualization of the model attention weights improves the interpretability of the model at the hidden state level and feature level. For the hidden state of different time steps, the LSTM network will focus on the hidden state of the last time step because it contains more information. The Transformer model gives almost equal attention weight to each day in the coding sequence. For the interpretable results at the feature level, daily max temperature, mean temperature, min temperature, and dew point temperature are the four most important features. The four characteristics of pressure, wind speed-related features, and holidays have the lowest average weights. [ABSTRACT FROM AUTHOR]

• Occupancy-based HVAC control using dynamic conditioning time estimation. • Deep learning algorithms are employed to provide online estimations of heat-up time. • Profitability of smart thermostats is studied via comprehensive financial analysis. • Occupancy information might negatively affect peak energy demand. • Conservative setback provides relatively poor financial gains. This paper presents a rule-based (RB) heating, ventilation, and air-conditioning (HVAC) control system using a multi-layer perceptron network, a deep learning algorithm, for estimating dynamic preconditioning time in residential buildings. The proposed system takes advantage of occupancy, indoor temperature, and weather data to make control decisions in buildings. The system performance is evaluated in terms of financial, demand-side management, energy-efficiency, and occupants' thermal comfort. The proposed approach considers the perfect occupancy prediction assumption to remove the impact of the uncertainty associated with occupancy prediction and to estimate an upper bound limit for the system performance. The system performance is compared with that of conventional rule-based control approaches to show its effectiveness. To select the optimal control system, the TOPSIS method, as a multi-criteria decision-making approach, is employed. The sensitivity of the proposed system to the temperature setback is also assessed by considering conservative, medium, and deep setback bounds. It is demonstrated that the proposed system outperforms other alternatives when the deep and medium bounds are utilized. This study reveals two limitations of occupancy-based control systems by investigating their performance from financial and peak-demand points of view. First, these systems can cause peak-demand issues and increase the on-peak energy consumption by up to 10%. Secondly, employing a conservative setback can significantly decrease the financial merits of the system, leading to a discounted payback period of 10.87 years for implementing smart thermostats. [ABSTRACT FROM AUTHOR]

Outdoor thermal comfort (OTC) directly impacts on health and wellbeing of inhabitants while it increases cooling energy demand of buildings. In this regards, different computational models and tools are developed to investigate the impact of built environments on pedestrian thermal comfort. However, in most of these models, the coeffects of solar radiation and local wind velocity are not simultaneously investigated where models are either simplified on solar calculations when are focused on wind or vice versa. This paper proposes a novel simulation framework to develop a high-resolution, but computationally efficient procedure, to couple radiative and convective fluxes in outdoor environments using computational fluid dynamics (CFD) and building energy simulation (BES) approaches. The workflow is implemented in Grasshopper platform fed by outputs of ANSYS-Fluent as the CFD tool and EnergyPlus as the BES tool. The performance of the framework is evaluated using a case study, representing a simplified neighbourhood on a typical hot day. In comparison with the traditional models, results highlight on a considerable change in the OTC values using the proposed model. Results show that the alteration is highly related to the temporal aspects and OTC results experience changes from 5% to 40% in compared to the original OTC values. [ABSTRACT FROM AUTHOR]

In civil engineering and architecture, sustainability requires energy optimization minimizing the energy amounts needed for heating and cooling. Revitalization of built heritage, except the renewal of the original identity, and preservation through adaptive reuse, must meet the requirements set within the framework of energy postulates. Given that the physical interventions for improvement of energy efficiency can affect the visual appearance of the building, energy retrofitting of built heritage under the protection regime represents a challenge in the management of cultural heritage. The paper aims to identify the most optimal measures to be applied to increase energy efficiency, depending on the protection level, using the fuzzy Analytic Hierarchy Process (AHP) method. Results show that for the highest protection level, the maximum degree of optimism indicates complete preservation of building identity, favoring indicators related to the technical systems, while for the medium protection level, all degrees of optimism favor internal insulation of thermal barriers and collector walls. Despite the allowed interventions for the lowest protection level, the optimistic view suggests alternative solutions not to greatly undermined identity. At the maximum degree of optimism, the application of indicators for technical systems dominates, which only in the last resort makes changes to the building. [ABSTRACT FROM AUTHOR]

Many New Zealand residential homes suffer from poor indoor air quality (IAQ). Cold, damp and mould-ridden homes can cause severe respiratory health problems. Poor IAQ can arise due to inadequate insulation and ventilation and is compounded when dwellers cannot afford to heat their homes during colder months. Grandfathering of standards means many New Zealand houses have single glazed windows and insufficient or no wall insulation. These have become mandatory for newly built houses since 2016 under the New Zealand Standard NZS4246:2016 Energy Efficiency. This paper aims to present the results of modified ultraviolet germicidal irradiation (UVGI) lights-dehumidifier coupled with two different types of filters (carbon-fibre or polyester). The modified devices were designed to improve ambient air temperature by removing moisture, particulate matter and reducing mould and bacteria growth in a room. Seven different scenarios were investigated, which include combinations of UV light and filtration. The results showed that the UVGI was superior to filtration only; however, the polyester filter with UV lights (PFUV) was the most effective configuration. The PFUV effectively impeded the mould growth, with a 13.3% reduction in relative humidity and a 4.1 °C increase in the room temperature in the absence of a heating source. The results showed good potential for improving the IAQ of buildings. [ABSTRACT FROM AUTHOR]

Abstract: Chiller sequencing control plays an important role in achieving air-conditioning system energy efficiency since chillers usually account for major part of system overall energy consumption in commercial buildings. This paper compares and evaluates the in situ performances of three commonly used chiller sequencing control strategies. These three control strategies are operating online in parallel on a management and communication platform in a super high-rise building in Hong Kong. The comparison and evaluation focus on the perspectives of chiller switch number, electrical peak demand and overall energy consumption in one week. Meanwhile, the different impacts of two systematic errors (i.e. positive errors which cause direct measurement larger than true value and negative errors which cause measurement smaller than true value) on each control strategy are also analyzed. The performance comparison demonstrates that the strategy, using fused cooling load measurement, achieved the best performance. The applications of the online computed chiller maximum cooling capacity and the advanced data fusion technique, which removes the negative impacts of sensor measurement uncertainties, can significantly improve the performance of chiller sequencing control. [Copyright &y& Elsevier]

Abstract: In this paper, we outline a framework and the algorithms that will enable a home controller to accomplish occupancy-moderated multi-zone, multi-inhabitant space-conditioning under a demand-driven pricing scheme for electricity. We investigated the effects that influencing factors such as the number of zones and inhabitants, randomness of occupancy patterns and thermal mass of the residence can have on the efficacy of occupancy-moderated zonal space-conditioning (OZS) under different scenarios. Simulations driven by real data and highly realistic proxy data reveal that OZS can achieve improvements averaging 23% over the case without under certain settings. Our investigations also revealed that a house with heavier thermal mass stands to gain as much as 15% from OZS with pre-conditioning than a lighter one. We further offer a few pointers on reducing the cost of space-conditioning using OZS under a demand-driven pricing scheme to the average homeowner based on our findings. [Copyright &y& Elsevier]

Abstract: A new system of solar air-conditioning, which adds the heat pump into the original solar air-conditioning, is proposed in order to improve the solar energy application grade. The new type of solar air-conditioning system is analyzed and compared with the original system. Calculations show that: (1) when the sun radiation intensity is high (0.8kW/m2), the cooling capacity of the new system is 1.7 times the original system under the given conditions of this paper. When the sun radiation intensity is low (0.2kW/m2), the cooling capacity of the new system is decreased by 70% compared to high radiation intensity conditions, and the original system could not provide refrigeration. (2) In a certain solar radiation intensity, new type solar air-conditioning system reduces the requirement of a high efficiency solar collection system (SCS). At a certain collector efficiency, it can operate stably by adjusting the water mass flow rate of SCS under different solar radiation intensities. (3) For the heat pump system (HPS) of the new type solar system, under the same rage of evaporation temperature and condensation temperature, R600a HPS has higher COP and less power consumption than R134a HPS under obtaining same cooling capacity condition. [Copyright &y& Elsevier]

Abstract: This paper presents the development and evaluation of the Belgrade Domestic Energy Model (BEDEM) for predicting the energy consumption and carbon dioxide (CO2) emissions of the existing housing stock. The distribution of energy use in relation to the end use is estimated as: space heating, 71%; light and appliances, 15%; water heating, 9%; and cooking 5%, while the distribution of CO2 emissions is space heating, 59%; light and appliances, 22%; water heating, 13%; and cooking 6%. Local sensitivity analysis is carried out for dwellings of different type and year built, and the largest normalized sensitivity coefficients were calculated for parameters which almost exclusively influence space heating energy consumption in housing. For all input parameters under investigation, the effects of the input uncertainty were linear for a moderate range of input change (Δx =±10%) and superposable for a small range of input change (Δx =±1%). However, the non-linear and non-additive properties of some input parameters over the wider range hinder the development of a simple but reliable model for estimating energy and CO2 reductions. The findings show that the uncertainty in the stock models predictions can be large and more work is needed in the area of the predictive uncertainty of stock models. [Copyright &y& Elsevier]

Abstract: The paper presents an incremental development of the methodology for chilled water system design optimization. Initially, the system configuration parameters are varied with fixed design conditions to confirm the established best practice design criteria, followed by a comprehensive system design optimization. The implemented simulation-based optimization approach couples the Dymola/Modelica dynamic modeling and simulation program with GenOpt generic optimization program to find optimal system configuration. A dynamic system model is developed to vary and simulate different chilled water system configurations. Optimization of the chilled water system is achieved at both design and configuration level using five design variables. Two discrete variables are related to system configuration: number of chillers and number of cooling towers and three continuous variables are related to system design: building load demand, temperature difference across condenser, and cooling tower fan speed. The strategy of varying system design and configuration variables together for overall system optimization proved to be the most energy efficient. For a fixed building load demand, power consumption of the considered system can be reduced 17–43% by selecting an optimal system configuration. [Copyright &y& Elsevier]

Abstract: Much of the energy utilised in domestic water heating is wasted to the drainage system by applications such showers, baths, dishwashers etc. The recovery of this waste heat from domestic waste water flows has been shown to be a viable method of improving the energy efficiency of buildings. However, many existing systems only operate satisfactorily when the heat exchanger is in a vertical orientation due to the nature of waste water flow within drain pipes. This orientation requirement presents a barrier to the full scale implementation of this technology as many dwellings may not have sufficient space to accommodate a vertical heat exchanger in their waste drainage system. This paper outlines the development and analysis of a horizontal drain water heat recovery system for domestic showers. The results of the investigation show that it is possible to recover energy from horizontal shower drains using a drain water heat recovery device at a satisfactory level of efficiency. The results also demonstrate that such a system may be economically viable depending on a number or external factors. The implementation of this technology on a national level was shown to have the potential to reduce energy usage and CO2 emissions significantly. [Copyright &y& Elsevier]

Abstract: In this paper, the energy and exergy utilizations in Jordan are analyzed by considering the energy and exergy flows for the year 2010 in the transportation, residential, and industrial sectors which represent more than 82% of total energy demand in Jordan. Detailed end-use models for the different sectors are established. For the transportation sector, the end-use model is constructed using scattered data from different governmental agencies. Due to lack of information for residential and industrial sectors, surveys covering 200 households and 180 industrial facilities were conducted and energy consumption data was gathered to establish detailed end-use models for the Jordanian residential and industrial sectors. Exergy analysis of Jordan indicates a less efficient picture than that obtained by the energy analysis. Energy and exergy efficiencies of Jordan were found to be equal to 48.2 and 23.2% respectively. It was found that the industrial sector is the most efficient energy and exergy sector. The study emphasizes the usefulness of the current methodology for analyzing sectoral energy and exergy utilization. This study will also provide an insight to energy analysts and policy makers in Jordan when considering the process of implementing energy policy measures such as energy efficiency standards in Jordan. [Copyright &y& Elsevier]

Abstract: Gas-engine driven heat pump (GEHP) working as water heater has higher energy utilization efficiency and can reduce more environmental pollution than gas-fired (oil-fired, coal-fired) boiler and electric motor driven heat pump (EHP). In the present work, a thermal model of a GEHP system working as water heater was established, and the performances (heating capacity, coefficient of performance (COP) and primary energy ratio (PER) of the GEHP system were also studied both by simulation and experiment. The results showed that the heating capacity increased with the increase of the rotary speed and water flow rate, but decreased with the increase of the hot water temperature. The COP and PER increased with the increase of the water flow rate, but decreased with the increase of the rotary speed and hot water temperature. The simulation results were well agreed with experimental data. The defrost time of the GEHP system was also studied by experiment, the results showed that the defrost time of both using waste heat recovered and reverse cycle defrost (RCD) was the shortest among the three defrost methods used in this paper. [Copyright &y& Elsevier]

Abstract: Energy efficient operation of chilled-water systems is important for the energy saving of commercial buildings. This paper presents an extremum seeking control (ESC) scheme for energy efficient operation of chilled-water system, and presents a Modelica based dynamic simulation model for demonstrating the effectiveness of the proposed control strategy. The simulated plant consists of a water-cooled screw chiller and a mechanical-draft counter-flow wet cooling tower. The ESC scheme takes the total power consumption of chiller compressor and tower fan as feedback, and uses the fan speed setting as control input. The inner-loop controllers for the chiller operation include two proportional–integral (PI) control loops for regulating the evaporator superheat and the chilled water temperature. Simulation was conducted for three scenarios: fixed condition, change in evaporator inlet water temperature, and change in ambient air condition. The simulation results demonstrated the effectiveness of the proposed ESC strategy, and the potential for energy saving is also evaluated. Also investigated is the ESC windup issue caused by the limitation of the fan''s maximum operation speed. A back-calculation anti-windup ESC scheme is applied and its effectiveness is validated by simulation results. [Copyright &y& Elsevier]

Abstract: Complex human or engineered network systems can be examined as a series of coexisting layers. A variety of dynamic perturbations, such as information flows across computer networks, traffic flows across transportation networks and the spread of energy saving practices across human networks, have been treated separately as single networks in previous research. However, because these phenomena often consist of human networks interacting with engineered networks, analyzing the properties of the multi-layer network systems may provide more accurate insights. In this paper, we examine a multi-layer network system to provide insight into the diffusion of energy consumption practices through peer networks within and across residential buildings. We introduce a new model-the Layered Network Model-that treats that treats a residential peer network and a geospatial building network as a single, layered network. We compare this model to a previously published Multi-Layer Interactive Network Model by simulating diffusion through a real multi-layer network system consisting of a residential peer network and a geospatial building network from three experimental data-sets. We found our model to be more accurate and efficient, hence contributing an efficient mathematical model and set of simulation algorithms that accurately capture the post-perturbation response of a layered, residential peer network and a geospatial building network. [Copyright &y& Elsevier]

Abstract: Due to the high energy consumption associated with the building sector, several legal documents with the aim of promoting energy efficiency have emerged in recent years, e.g. the Directive 2002/91/EC on the energy performance of buildings (EPBD) and its recast on 19 May 2010, Directive 2010/31/EU. The EPBD led many countries to adjust their own building energy-related regulations. The Portuguese thermal regulation for residential buildings, “Regulamento das Características do Comportamento Térmico de Edifícios (RCCTE)”, is a part of the transposition of the EPBD to Portuguese law. The main objective of this paper is to analyse the RCCTE in order to study the influence of some parameters considered important to the energy efficiency of buildings on energy performance and on the final energy certification rating. [Copyright &y& Elsevier]

Abstract: Centrifugal heat pump has to be coupled with gas boiler to supply high temperature water in radiator heating system. Regarding to hybrid heating system (HHS), operation strategy has significant impact on its annual energy consumption and cost. In this paper, the optimal operation strategy of the HHS composed of sewage-source centrifugal heat pumps and gas boilers was analyzed. Firstly, the performance models of the system components, including terminal radiator, heat pump, gas boiler and water pump were established respectively. Secondly, with the aim at minimizing the operating cost of the system the optimal operation strategy of the system was analyzed. Finally, the annual operating cost and energy consumption of the HHS were compared with these of coal-fired boiler heating system. The results indicate that the HHS offers significant reductions in energy consumption (45.2%) and operating cost (13.5%). Therefore, the HHS has a promising application prospect, the results provide reference for scientific operation of the HHS. [Copyright &y& Elsevier]

Abstract: The Brazilian government has started up a large social housing program for low-income families. Considering the large investment for this program, it is important to analyse the environmental impact to create a base for further improvement assessment. The goal of this paper is to visualise the energy use (embodied and operational) during the life cycle of case study for a house in the social housing program. The case study showed that the embodied energy (EE) is 7.2GJ/m2 or 30% of the total energy from the life cycle, the operational energy is 17.5GJ/m2. Half of the Embodied Energy is due to material use for maintenance and around 57% of the embodied energy is used in the wall construction. Compared to other international studies (5.8GJ/m2 per 50 years), the embodied energy is relative high (7.2GJ/m2 per 50 years) whereas the operational energy is only the half (17.5 compared to 36GJ/m2 per 50 year). The study indicates that the largest improvement potential for reducing the embodied energy is connected to the walls trough choosing materials and systems with less Embodied Energy and higher durability to decrease the need for maintenance and substitution of materials. [Copyright &y& Elsevier]

Abstract: Separate heat pipe heat exchanger (SHP heat exchanger) transports heat from the indoor air to the outdoor air by making use of the temperature difference. It consumes much less energy than split air-conditioners in telecommunication base stations (TBSs) because of no compressor. In this paper an annual energy-using simulation module of SHP was built up in the building energy simulation tool DeST. The SHP model was basing on the theoretical and experiment results of the heat transfer performance and the energy consumption. As the heat transfer quantity of SHP was interplayed with the indoor air temperature, the solution for the models of the dynamic thermal process in building and SHP heat exchanger was the key part, which was carried out by the coupling calculation. The reliability of SHP model and the coupling solution was verified by an empirical test. Finally, case study on the design of air-conditioning systems in TBSs was carried out to illustrate the engineering applications of SHP module. [Copyright &y& Elsevier]

Abstract: The commercial building sector has become the focus of many governmental energy reduction initiatives to achieve more sustainable development. Reducing building energy use starts by improving the design of buildings. To this end, energy modeling and simulation tools are used during the design phase to predict energy use and help designers choose and size the different building systems. Large discrepancies are however being observed between predicted and actual building energy performances. In order to determine the sources of errors and improve these predictions, the sensitivity of energy models to different input parameters needs to be evaluated. Studies in literature have extensively evaluated the sensitivity of models to the buildings’ technical design parameters. However, none considered the parameters related to the energy consumption behavior of occupants, leaving their impact on energy modeling unknown. This paper presents a comprehensive sensitivity analysis study performed on the occupancy behavioral parameters of typical office buildings of different size and in different weather zones. Significant sensitivity levels were observed, varying according to both building size and weather conditions. The highest sensitivity was obtained when varying the ‘heating temperature set point’ parameter in small-size buildings located in US weather zone 2 Dry. [Copyright &y& Elsevier]

Abstract: This paper investigates experimentally and numerically airflow characteristics of vortex, round, and square ceiling diffuser and its effect on the thermal comfort in a ventilated room. Three different thermal comfort criteria namely; mean age of the air, ventilation effectiveness, and effective draft temperature have been used to predict the thermal comfort zone inside the room. Experimentally, a sub-scale room is set-up to measure the temperature field in the room. Numerically, unstructured grids have been used to discretize the numerical domain. Conservation equations are solved using FLUENT commercial flow solver. The code is validated by comparing the numerical results obtained from three different turbulence models with the available experimental data. The validation shows that the standard k–ɛ turbulence model can be used to simulate these cases successfully. After validation of the code, effect of supply air velocity on the flow and thermal field is investigated and hence the thermal comfort and energy consumption. The results show that the saved energy by vortex diffuser is 1.5 times lower than that achieved by square or round diffuser. The velocity decay coefficient is nearly same for square and round diffusers and is 2.6 times greater than that for the vortex diffuser. [Copyright &y& Elsevier]

Abstract: This paper presents the effect of operating water mist system to enhance the energy efficiency of air-cooled chillers under various operating conditions. A thermodynamic model for an air-cooled chiller with twin refrigeration circuits coupled with a water mist system was developed and validated by measured operating data. The validated model was used to investigate how the thermal properties of the entering condenser air and the performance of the air-cooled chiller varied under different operating schemes with water mist pre-cooling. Under the conventional head pressure control (HPC) with a designed water mist generation rate, the coefficient of performance (COP) increased by up to 21.3%. The chiller performance could be improved further under variable condensing temperature control (CTC). Under CTC, chiller COP was increased up to 51.5% with optimal water mist generation rate. The potential energy savings of these chillers serving a representative office building in subtropical climate was evaluated, and CTC coupling with optimal water mist generation rate would reduce the annual total electricity consumption for cooling by 14.1%. The water consumption of the water mist system was comparatively small, comparing with the total water losses for an open-loop cooling tower system with equivalent heat rejection capacity. [Copyright &y& Elsevier]

Abstract: Better energy efficiency of ground coupled heat pump systems in comparison with traditional applications leads to continued growth in the number of installations for space conditioning. The solution with vertical heat exchangers is the most widespread. The design of the borehole heat exchangers (BHEs) is a nodal point, both from an energy efficiency and an economic point of view. In literature, several methods to design these systems are available. However, to promote their application, easy-to-use procedures are required; furthermore designers very often are discouraged from the use of not-open or complicated computational tools. Among the literature models, the ASHRAE method is surely the simplest procedure and, as a consequence, it is suitable for this goal. In this approach, sizing of the BHE length is strongly affected by the parameter named penalty temperature, which is an index to evaluate the long-term behaviour of the borehole field. In this paper, a review of this index is reported and in addition a new approach for its evaluation is presented. Furthermore, a detailed analysis of the proposed method is performed on a real case-study building with only heating conditioning. [Copyright &y& Elsevier]

Abstract: This paper discusses the issue of selecting the design solution that best accords with an articulated preference of multiple criteria with an acceptable performance band. The application of a newly developed multi-criteria decision-making tool called RR-PARETO2 is presented. An example of HVAC design is used to illustrate how solutions could be selected within a multi-criteria optimization framework. In this example, five criteria have been selected, namely, power consumption, thermal comfort, risk of airborne infection of influenza and tuberculosis and effective differential temperature (Δt eq) of body parts. The goal is to select the optimal air exchange rate that makes reasonable trade-offs among all the objectives. Two scenarios have been studied. In the first scenario, there is an influenza outbreak and the important objective is to prevent the spread of infection. In the second scenario, energy prices are high and the primary objective is to reduce energy. In both scenarios, RR-PARETO2 algorithm selects solutions that make reasonable trade-offs among conflicting objectives. The example illustrates how objectives such as reduction of airborne disease transmission and maximizing thermal comfort can be incorporated in the design of a practical, full-scale HVAC system. [Copyright &y& Elsevier]