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• A pre-1919 primary school with single glazing in Edinburgh has an oversizing of its space heating system of 32 % at design conditions. • Supply temperature can be operated below 70 °C all year round. • Supply temperatures can be reduced below 55 °C all year-round during daytime. As part of the decarbonization of its existing building stock the UK needs to replace gas boilers with heat pumps and low-temperature heat networks. Both technologies are efficient at supply temperatures of 55 °C, with a maximum of 70 °C for heat networks, when existing systems have been designed to operate at 82 °C. Most space heating systems are expected oversized and operate most of the year in part-load, which facilitate the temperature reduction, but little is known about the degree of oversizing. This paper uses the case study of a pre-1919 school in Edinburgh to evaluate the true oversizing of its heating system and its consequences on minimum supply temperatures. This building is still equipped with single glazing and is therefore a worst-case scenario. An oversizing of 32 % was estimated which enables the use of a supply temperature below 70 °C all year round. Moreover, the supply temperature can be kept below 55 °C all year round during daytime due to internal heat gains. In conclusion, this building shows a nascent readiness for low-temperature heat. It would benefit from energy efficiency measures such as double-glazed windows, but this is not pre-requisite. Those results are important for the heat network industry when sizing their systems, but also energy and asset managers when they schedule renovation programmes to have their buildings low-temperature-ready. [ABSTRACT FROM AUTHOR]

The German Federal Government put its first net zero office building in operation in 2013 anticipating EU requirements for all public administrations to solely built “nearly zero energy buildings” from 2019 onwards. The two-storey building is situated in Berlin and has been designed for having an overall annual energy demand lower than the in-situ conversion of renewable energies. The paper shows the results of the first year of the operation. The overall annual electric usage is near to the expected value. Nevertheless, intensive monitoring showed differences between the expected and the measured electric usage in the areas of heating and domestic hot water (+172%), ventilation (−36%), lighting (−33%), equipment and auxiliaries (−14% and −13%, respectively), yield of the PV-system (+32%). A numerical model was created to investigate these deviations as well as to evaluate the impact of possible actions aimed at further improving the energy demand of the building. The model was calibrated with measured data, data from surveys, occupancy schedules, and validated by means of different indexes, among which the mean bias error (MBE). The MBE between monitored and simulated energy performance is below ±2% for all stated areas of energy usage. Analogously, the energy needs for cooling, monitored and simulated, as well as the trends of the indoor air temperature in both heating and cooling seasons, are in a very good agreement. In detail, the monthly MBE for the indoor temperature, in specific summer and winter periods and in the considered rooms, is below the threshold of ±5%, with values slightly higher (anyway lower than ±6%) only at the ground floor. Finally, the paper shows that the reasons for the detected deviations in electric energy usage can mainly be related to the usage pattern of the building and to the occupants’ behavior. In order to ensure energy efficiency as high as planned, a suitable monitoring of the energy performance is fundamental. It enables the calibration and validation of tailored energy models to detect possible malfunctions as well as propose actions aimed at further reducing the energy usage of the building. [ABSTRACT FROM AUTHOR]

At present, China's public building energy efficiency improvement projects lack vitality in the market due to the weak awareness of energy efficiency among the participating subjects. Therefore, improving the knowledge and awareness of all participating parties has become the key to effectively promoting energy efficiency improvement in Chinese public buildings. This paper researches the knowledge demand of key subjects for energy efficiency improvement in public buildings(EEIPB), establishes a knowledge demand indicator system for EEIPB, and proposes targeted knowledge improvement methods. Firstly, the knowledge demand of key subjects for EEIPB is identified by using grounded theory, and the knowledge demand indicator system for EEIPB is established. Secondly, the knowledge demand categories are determined with the help of the improved Kano's model, and the priority of the knowledge demand elements of each subject is derived through Better-Worse index analysis. Finally, suggestions on the learning paths for Better-Worse index analysis are put forward. It is found that the demand for various subjects for knowledge on EEIPB is mainly focused on five aspects: incentive policies, regulations, standard specifications, market, and technology. In terms of demand, the types of knowledge demand elements for EEIPB of each subject are mainly One-dimensional Attributes and Mixed Attributes among which incentive policies and market are the focus of attention of each subject. In addition, there are both commonalities and differences in the knowledge demands of each subject. This research will help government authorities formulate effective promotion measures for the demand for energy-efficiency improvement knowledge in public buildings and raise the level of energy-efficiency knowledge awareness of all subjects in the public building industry. [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]

• The effects of green roofs and practical green façades within courtyard area on public buildings investigated for "Hot Summer, cold Winter" region of China. • Internal surface temperatures for areas with and without external greening monitored and compared. • Heating and cooling energy consumption before and after greening compared from computer simulation as well as from smart meter readings. • Actual heating and cooling energy consumption before and after greening compared using statistical analyses. T -statistics and p -values show significant reductions were achieved. The "Hot Summer Cold Winter" climate region of China is one of the most challenging regions for providing occupant comfort in buildings, with high demands for heating as well as cooling, together with high humidity levels. Although the performance of buildings has improved with the implementation of the new Chinese National Building Standards for the Zhejiang Province, it is believed that adding passive strategies could help to alleviate the problem even further. This paper aims to investigate the effects of adding horizontal greening (green roof) and vertical greening in the courtyard area to existing public buildings in the "Hot Summer Cold Winter" climate region of China. Using computer simulation and measurements from a monitored case in the city of Ningbo, the effects of green retrofitting on human comfort and energy consumption are analysed. Simulation results suggest that with partial horizontal and vertical greening, the cooling load could be reduced by 8.8% and heating load by 1.85%. Comparisons between actual energy use before and after greening on the case building showed significant reductions in both winter and summer, confirming the positive effects of vertical and horizontal greening of public buildings in this region. [ABSTRACT FROM AUTHOR]

Abstract: This paper takes a close look at the China national standard GB50189-2005, Design Standard for Energy Efficiency of Public Buildings, which was enforced on July 1, 2005. The paper first reviews the standard, then compares the standard with ASHRAE Standard 90.1-2004 to identify discrepancies in code coverage and stringency, and recommends some energy conservation measures that can be evaluated in the design of public buildings to achieve energy savings beyond the standard. The paper also highlights several important features of 90.1-2004 that may be considered as additions to the GB50189-2005 standard during the next revision. At the end the paper summarizes the latest developments in building energy standards and rating systems in China and the US. [Copyright &y& Elsevier]

The paper suggests a methodology for energetic buildings diagnosis for the Perugia University [Energy Buildings 1436 (2002) 1; B. Puttinger, Guideline for implementing energy audits in public buildings, Landes Energie Verein; R. Recalcati, G. Dall’O’, Procedure for buildings energetic certification, Punto Energia, Brescia (1998)].All of the university buildings have been put into six poles according to their geographical location.First of all, the entire area was subdivided into blocks according to didactics, office, and research areas. On the basis of this division, the utilization coefficient of the specific areas was determined for each pole.The paper suggests a method for pole electric consumption dividing into the three terms related to didactics, office, and laboratory block by the definition of the three “area indexes” Cdid.A, Coff.A, and Clab.A which represent the specific consumption per square meter of dedicated area. Their values, and in particular Clab.A value, vary according to the nature of the activities carried out in each pole. Starting from “area indexes”, the three “user indexes” (Cstu.U, Cper.U, and Cres.U) were then defined considering students, personnell, and researcher, separately.Area and user indexes’s yearly evaluation, dependent on the users number per typology and the blocks area, allows to identify the increasing or decreasing characteristic of the intensity of the activities carried out in each pole, to determine if consumptions depend mainly on class activities being carried out or on the use of electric heater and air conditioning systems.Finally, thermal consumptions were analyzed by evaluating the yearly energy amount and the specific consumption of each pole according to age and state of the buildings. [Copyright &y& Elsevier]

• A well-functioning space heating system can operate below 70 °C for 98% of the year and below 55 °C for 71% of the year. • The performance gap between measured and calculated energy use is widening across building age groups, with a clear increase for post-1980 buildings. • Pre-1980 buildings can operate with supply temperatures below 70 °C for 96–99% of the year and below 55 °C for 67–71% of the year. • Building envelope improvement, whilst recommended, is not a pre-requisite for using low-temperature supply in pre-1980 buildings. • Post-1980 buildings could have limitations in respect of using low-temperature heat under windy conditions. Decarbonising heat in the UK by 2050 will require the wider adoption of low-temperature heat. Current systems, largely relying on gas boilers, have design operating temperatures of 82/71 °C (supply/return) while new standards for 4th Generation District Heating are 55/25 °C. Local authorities must set-up strategies to get their buildings "Heat network ready" but this raises the question of the ability for existing buildings to use low-temperature heat. The aim and the novelty of this paper is to establish a relationship between an energy 'performance gap' in Scottish public buildings and their ability to use low-temperature heat. This performance gap has been evaluated for 121 non-domestic buildings, primarily schools, operated by The City of Edinburgh Council. Space heating system are assumed oversized by 10%. The results show that renovation of the building envelope, while highly desirable, is not a pre-requisite for using low-temperature heat in pre-1980 constructed buildings, which represent 64% of the stock. It also highlights that post-1980 buildings, predominantly utilising mechanical ventilation systems, demonstrate an increasing performance gap which could limit their ability to use reduced operating temperature, especially in windy conditions. [ABSTRACT FROM AUTHOR]

Emission reduction in buildings is essential to combat climate change. However, current strategies failed to balance development and emissions reduction goals. This paper selects a public building in China and simulates its initial energy consumption and carbon emissions. Then it establishes a multi-objective optimization model to explore cost-effective and emission-reduction strategies, considering photovoltaic and ground-source-heat-pump (GSHP) systems. Finally, NSGA-Ⅱ is used to solve, and sensitivity analysis is carried out. Results show that: (1) Energy consumed by the air conditioning system is the largest in January for heating and in July for cooling, validating the accuracy of the energy simulation model. (2) Economic efficiency and emission reduction effect are better when photovoltaic and GSHP systems are implemented simultaneously. (3) Electricity price, initial investment cost, annual solar peak hours, and the proportion of shallow geothermal energy significantly impact carbon emissions and cost. (4) The photovoltaic and power grid substitution ratio will exceed 8% every five years, and all substitutions will be completed in 2050. After adopting the GSHP system, the complete replacement will be advanced to 2045. Setting subsidies significantly shortens the payback period of investment and ensures firms' economic benefits. In summary, using photovoltaic and shallow geothermal energy is conducive to reducing emissions and saving costs in the long term. [ABSTRACT FROM AUTHOR]

• An interactive framework of outdoor paving and indoor ventilated atrium are proposed. • The balance of thermal comfort and carbon abatement is considered. • Outdoor environment and indoor atrium have various effects on comfort and emission. • Water pavement and 135° atrium skylight direction can reduce 14% emissions. Large-scale public buildings usually use active means to improve indoor thermal comfort, such as cooling and heating by centralized air conditioning, which can increase building carbon emissions. It is urgent to balance the comfort and carbon abatement. Passive means have the potential to reduce building carbon emissions, such as the atrium. However, the effect of atrium on comfort and carbon abatement is influenced by outdoor environment, which is ignored in the traditional research. Therefore, this paper proposes an interactive design framework for outdoor environmental paving (O-EP) and indoor ventilated atrium skylight orientation (I-VA). Taking a large-scale public building in Xinghua city as an example, three common outdoor pavement forms (hard paving, shrub greenery, water bodies) and five building atrium skylight orientations (0°, 45°, 90°, 135°, 180°) are selected. Carbon abatement rate and adaptive predicted mean vote (aPMV) are used as evaluation indicators for carbon abatement and comfort respectively. The couple of O-EP and I-VA on building carbon abatement and comfort is obtained by analysis of correlation and ANOVA. Numerical simulations are validated by experimental data. The results show that (1) different combinations vary significantly, annual carbon abatement rates and comfort are 17.5% and 15% higher for the combination of water bodies of O-EP and 135° of I-VA than for the worst; (2) correlation analysis shows that carbon abatement rate is correlated with O-EP at the 0.01 level and not with I-VA; (3) in the warmer seasons, comfort is correlated with O-EP at the 0.01 level and not with I-VA; in the cooler seasons, comfort is correlated with I-VA at the 0.01 level and not with O-EP. This study can provide an important reference for design strategies for low carbon development and green buildings. [ABSTRACT FROM AUTHOR]

• Cost-effective and sustainable energy systems retrofit for buildings. • 2nd life Li-Ion batteries in polygeneration systems for buildings. • To cut off the natural gas consumption at affordable cost. The building sector represents around one-third of the energy related to the EU CO 2 eq emissions, which makes it a crucial sector for achieving the EU's energy and environmental goals. Thus, the EU has established a legislative framework to foster, among others, the modernisation of the existing building stock through a better energy system integration. In this sense, bearing in mind the needs of energy system retrofit of the public buildings in Spain, this paper carried out a thorough analysis of different trade-off solutions obtained from the multiobjective optimization of a polygeneration system for the TR5 building of the Polytechnic University of Catalunya. The results highlight the selection of PV panels, cogeneration modules and 2 nd life Li-Ion batteries, among others, to achieve cost-effective and sustainable energy systems. By covering the available area, 2000 m 2 , the PV panels attend about 23% of the electricity required for the building. On the other hand, considering the current geopolitical tensions, it presents a potential configuration that allows to cut off the natural gas consumption reducing about 6% the current cost. The study was carried out by using a Mixed Integer Linear Programming model maximizing the Net Present Value of the project considering the environmental impact. [ABSTRACT FROM AUTHOR]

Abstract: This paper aims to investigate the effects of retrofitting existing public buildings in the “Hot Summer Cold Winter” climate region of China, using simulation and a case study, to see how retrofitted public buildings perform in the face of climate change in the region. This area of China is one of the most challenging regions for providing occupant comfort in buildings, with high demands for heating as well as cooling, together with high humidity levels. The simulation results suggest that energy reduction of up to 40% with improvements to the building enclosure is possible by retrofitting current existing public buildings to the new Chinese National Standard for the Zhejiang Province. Requirements for combating possible increase in energy consumption from heating and cooling demands due to future climate change was also investigated, and it was found that by simply improving U-Values of the building envelope to the new national standards set for the Zhejiang Province, the effects of future climate change can be nullified up to the 2080s. Further improvements to having similar standards as developed countries such as England and Wales will have less significance and cannot nullify the effects of climate change from the newly retrofitted public buildings. However, this can be achieved by involving other energy-saving strategies and installing suitable energy-saving technologies for the region. [Copyright &y& Elsevier]

Abstract: Hainan province is the only tropical and island province in China, with the unique climatic and geographical features. It has a different energy performance in public buildings from those in the inland areas. This paper investigated the current situation of energy consumption of the sampled public buildings, including 26 hotels, 24 office buildings and 7 department stores, through analyzing utility billing data, on-site survey and measurement, and site operational records. The breakdowns of energy consumption found out that the electricity dominated the energy consumption for all the sampled buildings and the air conditioning system played a key role in the energy consumption of major building services. By analyzing the main factors for building energy consumption, the annual average energy use indexes were calculated to be 141.63kWh/m2, 87.70kWh/m2, and 166.95kWh/m2 for hotels, office buildings and department stores, respectively. Besides, the comparison between Hainan province and other areas revealed that the building energy consumption of this tropical province was at a low level. Because indoor environment quality can influence the health and work efficiency of humans in buildings, field tests on the indoor environment quality were also carried out, and the performance of indoor environment quality was rated. [Copyright &y& Elsevier]

Abstract: Traditional houses and public buildings in Thailand were constructed from materials of low thermal mass and the walls were not insulated. Brick and concrete began to replace wood as walling material before air-conditioning was introduced into the country. New large buildings have glazed and closed windows so interior spaces require air-conditioning and forced ventilation. Up to the present, no insulation is used on walls. This paper presents results from an experimental and simulation study on comparative energy and economic performance of walls used to enclose air-conditioned spaces. The walls are externally and internally insulated to different thicknesses. The spaces are assumed to serve three commercial functions. Results show that insulation can generally help improve thermal performance of walls, but the function that a space serves dictates where insulation should be placed and how cost effective it is. [Copyright &y& Elsevier]

Abstract: This paper presents two case studies of performance improvement alternatives. The first one is the 52.5MWe cogeneration plant at the Suvarnabhumi Airport, and the second is the 9.9MWe cogeneration plant of the government office building complex. Both plants are located in Bangkok. Performance improvements assume changing system design and operational plans during on-peak and off-peak periods with applying chilled water storage for more flexible operation. Such analysis gives opportunity for improvement of plant efficiency, primary energy saving, emission reduction and economical benefits. In case study 1, the selection of new prime mover results in overall efficiency improvement from 48% to 61%, 24% increase of primary energy saving, and 27% improvement of CO2 emission reduction. Significant amount of primary energy is saved 1451TJ/a and CO2 emission reduction is 129,271tCO2/a. The profit is increased to 24.80 Million US$/a and the payback period is 4.77 years. In case study 2, the application of chilled water storage leads to maximum profit of 2.63 Million US$/a. The results show that the selection of plant components should be made very carefully in the design stage, as well as that permanent control and optimization of plant operation in the exploitation phase is essential. Economic aspects of cogeneration plants are more sensitive to changeable input parameters than classical separate heat and power generation since cogeneration plants are more complex in the aspects of process configuration and products costs/values (electricity, steam, hot water, and chilled water). Having in mind the future development of the natural gas distribution network in Thailand, it can be estimated that the potential of power generation in public buildings is around 1.3GWe. Comparing the Thailand total primary energy supply for commercial buildings, it means reduction of about 9.1%. [Copyright &y& Elsevier]

[Display omitted] • Investigating ventilation for precaution and control of COVID-19 in high-occupant-density public environments. • Balancing a low-infection-risk yet energy efficient ventilation control. • Developing a smart low-cost ventilation control strategy based on occupant-density-detection algorithm. • Providing a feasible and promising solution to fight against COVID-19. Ventilation plays an important role in prevention and control of COVID-19 in enclosed indoor environment and specially in high-occupant-density indoor environments (e.g., underground space buildings, conference room, etc.). Thus, higher ventilation rates are recommended to minimize the infection transmission probability, but this may result in higher energy consumption and cost. This paper proposes a smart low-cost ventilation control strategy based on occupant-density-detection algorithm with consideration of both infection prevention and energy efficiency. The ventilation rate can be automatically adjusted between the demand-controlled mode and anti-infection mode with a self-developed low-cost hardware prototype. YOLO (You Only Look Once) algorithm was applied for occupancy detection based on video frames from surveillance cameras. Case studies show that, compared with a traditional ventilation mode (with 15% fixed fresh air ratio), the proposed ventilation control strategy can achieve 11.7% energy saving while lowering the infection probability to 2%. The developed ventilation control strategy provides a feasible and promising solution to prevent transmission of infection diseases (e.g., COVID-19) in public and private buildings, and also help to achieve a healthy yet sustainable indoor environment. [ABSTRACT FROM AUTHOR]

• A CBR approach is developed for the parametric design of building envelopes. • Case reuse and revise methods are proposed. • Different reasoning strategies are necessary according to design requirements. • Existing cases are promising in the energy-efficient design of building envelopes. The building envelope is a key factor affecting the energy efficiency of buildings. Often, building envelope design requires both explicit knowledge and tacit knowledge. In practice, the tacit knowledge embedded in existing envelope design cases is significantly underused. To enhance the application of such knowledge, this paper proposes a case-based reasoning (CBR) model for the decision support of building envelop design during the preliminary design stage. A case library of 100 certificated green public and commercial buildings is used to develop the model. An experiment on a test case is performed to verify the methodology and usability of the model. Furthermore, records for 25 certificated green public buildings are used to validate the effectiveness of the model. The result shows that the accuracy rate of the CBR model is 84% when considering heating and cooling demands of envelopes. In conclusion, the proposed CBR model is promising for improving the efficiency of envelope design for public and commercial buildings while reducing the reliance on expert participation. [ABSTRACT FROM AUTHOR]

• Implementation of smart wearable sensors investigated. • Two office buildings included in the case study with different climates. • Experimental readings presented and discussed in order to analyze thermal comfort. • Metabolic models developed with artificial neural networks (multilayer perceptron). This paper reports and discusses the results of a field study focusing on the examination of thermal comfort conditions in two public buildings in Croatia. The wearable sensors were used for monitoring the occupants' metabolic responses, along with the standard equipment for measuring thermal comfort. The occupants' subjective comfort sensation was also investigated through a survey questionnaire and was used in conjunction with the measured data. A total number of eight occupants participated in the study, located in two office buildings in different climates. The modeling of the metabolic responses was obtained by means of artificial neural networks and the simulated values were compared with the measured ones. The validation of the models showed overlapping of 90%. However, they should be tested on a larger number of occupants. The study results revealed that the MET response usually varied between values 1.0 and 2.0, no matter the season, which is rather high for office activities according to standards, and indicates the inapplicability of static MET value usage in the calculation of PMV indexes. The implementation of wearable sensors provided accurate information on the dynamic changes of the building occupant's metabolic rate during working hours, enabling the reliable model algorithm creation to increase occupant satisfaction and potential energy savings. Finally, the differences between the two examined buildings' thermal conditions were analyzed and useful findings regarding age, gender and physical fitness of occupants and their satisfactory level of comfort conditions were presented. [ABSTRACT FROM AUTHOR]