Effect of building energy efficiency standards on carbon emission efficiency in commercial buildings

The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.

Country-level meteorological parameters for building energy efficiency in China

Accurate basic data are necessary to support performance-based design for achieving carbon peak and carbon neutral targets in the building sector.Meteorological parameters are the prerequisites of building thermal engineering design,heating ventilation and air conditioning design,and energy consumption simulations.Focusing on the key issues such as low spatial coverage and the lack of daily or higher time resolution data,daily and hourly models of the surface meteorological data and solar radiation were established and evaluated.Surface meteorological data and solar radiation data were generated for 1019 cities and towns in China from 1988 to 2017.The data were carefully compared,and the accuracy was proved to be high.All the meteorological parameters can be assessed in the building sector via a sharing platform.Then,country-level meteorological parameters were developed for energy-efficient building assessment in China,based on actual meteorological data in the present study.This set of meteorological parameters may facilitate engineering applications as well as allowing the updating and expansion of relevant building energy efficiency standards.The study was supported by the National Science and Technology Major Project of China during the 13th Five-Year Plan Period,named Fundamental parameters on building energy efficiency in China,comprising of 15 top-ranking universities and institutions in China.

Supply and demand subject behavior of building energy efficiency in market fostering

Consumers and developers are the market transaction subjects which drive the development of building energy efficiency market. High energy prices, unreasonable heating system, information asymmetry of building energy suppress demand of energy efficiency construction; high technical risk and construction cost, nonstandard market restrict the supply of energy efficiency construction. To promote the development of building energy efficiency, we must set up effective incentive policies for both sides of the market transaction, improve the supervisory system, promote the technological progress, build the information sharing platform, so as to achieve the purpose of cultivating and improving the building energy efficiency market system, regulating the behavior of supply and demand subject, building the mutually beneficial and cooperative partnership, and realizing the balance of interests.

REAL ESTATE DEVELOPERS’CONCERNS ABOUT UNCERTAINTY IN BUILDING ENERGY EFFICIENCY(BEE)INVESTMENT-A TRANSACTION COSTS(TCS)PERSPECTIVE

Buildings account for 40% of global energy consumption and nearly one-third of global CO_(2) emissions;and the resulting carbon footprint significantly exceeds that of all forms of transportation combined. Attractive opportunities exist to reduce buildings’ energy use at lower costs and higher returns than in other sectors. This paper analyzes the concerns of uncertainty, in terms of transaction costs, to the real estate developers when they make decisions about investing in Building Energy Efficiency (BEE). To solicit views of developers regarding BEE investment, in-depth interviews were conducted with 15 executives and architects who work in big real estate development firms covering 80% of real estate activities in Hong Kong. This research applies transaction cost economics (TCE) to study the underlying reasons resulting from uncertainty that cause market reluctance to accept BEE by choice. It provides a detailed analysis of the current situation and future prospects for BEE adoption through studying the impacts from three aspects: economic, market and policy uncertainties. It delineates the market and suggests possible policy solutions to overcome the uncertainties and to attain the large-scale deployment of energy-efficient building techniques. The findings establish the groundwork for future studies on how to choose a particular policy package and what roles government should play to solve the existing problems in BEE development.

Building energy efficiency and COVID-19 infection risk:Lessons from office room management

To prevent COVID-19 outbreaks,many indoor environments are increasing the volume of fresh air and running air conditioning systems at maximum power.However,it is essential to consider the comfort of indoor occupants and energy consumption simultaneously when controlling the spread of infection.In this study,we simulated the energy consumption of a three-storey office building for postgraduate students and teachers at a university in Beijing.Based on an improved Wells-Riley model,we established an infection risk-energy consumption model considering non-pharmaceutical interventions and human comfort.The infection risk and building energy efficiency under different room occupancy rates on weekdays and at weekends,during different seasons were then evaluated.Energy consumption,based on the real hourly room occupancy rate during weekdays was 43%–55%lower than energy consumption when dynamic room occupancy rate was not considered.If all people wear masks indoors,the total energy consumption could be reduced by 32%–45%and the proportion of energy used for ventilation for epidemic prevention and control could be reduced by 22%–36%during all seasons.When only graduate students wear masks in rooms with a high occupancy,total energy consumption can be reduced by 15%–25%.After optimization,compared with the strict epidemic prevention and control strategy(the effective reproductive number Rt=1 in all rooms),energy consumption during weekdays(weekends)in winter,summer and transition seasons,can be reduced by 45%(74%),43%(69%),and 55%(78%),respectively.The results of this study provide a scientific basis for policies on epidemic prevention and control,carbon emission peak and neutrality,and Healthy China 2030.

A New Dynamic and Vertical Photovoltaic Integrated Building Envelope for High-Rise Glaze-Facade Buildings

Substantially glazed facades are extensively used in contemporary high-rise buildings to achieve attractive architectural aesthetics.Inherent conflicts exist among architectural aesthetics,building energy consumption,and solar energy harvesting for glazed facades.In this study,we addressed these conflicts by introducing a new dynamic and vertical photovoltaic integrated building envelope(dvPVBE)that offers extraordinary flexibility with weather-responsive slat angles and blind positions,superior architectural aesthetics,and notable energy-saving potential.Three hierarchical control strategies were proposed for different scenarios of the dvPVBE:power generation priority(PGP),natural daylight priority(NDP),and energy-saving priority(ESP).Moreover,the PGP and ESP strategies were further analyzed in the simulation of a dvPVBE.An office room integrated with a dvPVBE was modeled using EnergyPlus.The influence of the dvPVBE in improving the building energy efficiency and corresponding optimal slat angles was investigated under the PGP and ESP control strategies.The results indicate that the application of dvPVBEs in Beijing can provide up to 131%of the annual energy demand of office rooms and significantly increase the annual net energy output by at least 226%compared with static photovoltaic(PV)blinds.The concept of this novel dvPVBE offers a viable approach by which the thermal load,daylight penetration,and energy generation can be effectively regulated.

Berkeley Lab and Tsinghua University to Tackle Building Energy Efficiency

Berkeley Lab and Tsinghua University forged ties on Aug. 12, 2009 to promote the development and implementation of building energy efficiency, a move intended to reduce energy consumption and greenhouse gas emissions in the U.S and China.

A New Type of Paper-frame Cavernous Material and Its Application in Energy Efficiency in Buildings

This paper introduces a new type of paper-frame cavernous material, which is a made-up hollow material, by using silicate-cinder size to drench and daub. It possesses excellent performances such as light-weight, high-intensity, fire-resistance, sound-insulation, heat-insulation and no-pollution. Composed with concrete materials, a new type of bearing and energy-efficient block can be gained, which is kind of excellent wall materials and has a wide application prospect.

Evaluation of Radon Indoor Pollution Risk in High Efficiency Energy Buildings

The target of achieving high energy efficiency standard in order to comply with the EU Directives is leading to remarkable efforts to improve the performance of the building envelope. Excellent thermal insulation and airtight sealing of leakages are of the utmost importance to fulfil the expected targets. Unfortunately, airtightness produces the negative effect of increasing the indoor concentration of air pollutants like radon. Despite the seriousness of the problem is generally misconceived, long-term exposition to radon is acknowledged to be the second cause of lung cancer after smoke. The paper outlines the implications for the building sector and focuses on design and preventive criteria as well as on mitigation and remedial techniques.

Sensibility Analysis of the Brazilian Standards for Energy Efficiency Regarding the Variation of Internal Load Density in Office Buildings in Brazilian Bioclimatic Zones 1 and 7

The RTQ-C （Technical Requirements of Quality for the Energy Performance Level of Commercial Buildings） publication classified the buildings in five efficiency levels. In RTQ-C, the evaluation can be done with two methods： a prescriptive method and a simulation one. This paper aims to identify the sensibility of the prescriptive method RTQ-C regarding the variation of equipment internal load density in office buildings in bioclimatic Zones I and 7 of the Brazilian bioclimatic zoning. The research results show that the building with walls and roof configured to meet specific prerequisites for energy efficiency Levels B and C had a lower consumption than buildings that meet the prerequisites to Level A. The study also showed that buildings with high internal load density of equipment, maximum shape factor and high, with walls and roofs with higher thermal transmittance, have lower power consumption than constructions with an envelope with greater thermal resistance. The increase in internal load density causes an increase in the internal heat generated by the large amount of equipment. In buildings with higher thermal insulation （Level A）, the internal heat is maintained in the environment, causing overheating and the need for an air conditioning system.

How to achieve energy efficiency in buildings without compromising indoor air quality:A case study on enthalpy exchangers

As a representative heat recovery device,the fixed-plate enthalpy exchanger possesses the advantages of high recovery effectiveness,low pressure drop,and small space occupied.Still,indoor contaminants may transfer to fresh air through the enthalpy exchanger simultaneously,causing cross-contamination risk.However,the cross-contamination risk of the fixed-plate enthalpy exchanger has been under-researched in previous studies.As a result,this study experimentally investigates the energy performance,formaldehyde and ammonia transfer rates of paper-based and membrane-based enthalpy exchangers.The results illustrate that the enthalpy recovery effectiveness of the plate exchangers ranges from 60%–85%.The formaldehyde transfer rate through the exchangers varies from 5%–23%,and the ammonia transfer rate is 0–15%.The high effectiveness and low contaminant transfer rates are conducive to the promising application of the fixed-plate enthalpy exchangers.In addition,the energy reclaimed increases with the increase of the absolute indoor-outdoor enthalpy difference.The formaldehyde and ammonia transfer rates and cross-contamination risk slightly decrease with increasing temperature but significantly increase with increasing humidity.Moreover,the experimental results demonstrate that the contaminant transfer rates through the membranebased exchanger are lower than those of the paper-based exchanger.This study provides a reference for the fixed-plate enthalpy exchanger design in practical applications.

Construction of building energy conservation incentive policies under government regulation: Based on the subjects' behavior analysis

Building energy efficiency is a long-term strategy to achieve sustainable development, but the inconsistencies of main interests during the implementation lead to the need for government regulation in building energy conservation. Implementation of building energy efficiency of government regulation covers three aspects of construction and involves relevant participators, so the paper analyzes interests and roles of the related subjects in building energy saving, explore the motivations and its conversion mechanism of each player, and dissect the game relationship of associated earnings of developers' and consumers' behaviors selection under government control. Finally, the paper proposes basic requirements of building incentive policies for related subjects under government control to regulate the main behaviors of subjects in building energy efficient buildings and achieve energy efficiency goals and balance of all parties' benefits.

Integration of Energy and Fire Prevention Systems in Green Building

Green buildings should be sustainable, efficient, economical, and to improve the quality of life of users and nearby residents. Unfortunately, some architecture features fostered by energy and environmental certifications do not comply with fire prevention codes. Several factors can influence a building＇s energy efficiency and fire safety, such as bigger or smaller glass areas, building material thermal inertia, and the use of sustainable solutions such as green roofs. In this work, a methodology for integrating energy efficiency and fire prevention in green buildings is presented. A case study comparing a full glass skin and a building with 40% window size is considered. Also, the methodology permits modifications for obtaining a safe and energy efficient building.

Apartments for Elderly People in a Building Designed as a Retirement Home

The building as a model for conceiving a project： The future of the construction industry will be a science of what to do with the built environment rather than the classical problem of what is needed to be built. The necessary areas for living, working and entertainment are probably already built, but we need to update them to comply with the new codes, the new needs and the new uses of our society. For this reason we are looking at new ways of addressing our profession： Firstly we have to decide whether a new way of living requires a new space or if there is already an existing space available. Secondly, we have to adapt the chosen space to the new requirements of society and the new codes and regulations. Thirdly, we have to think about the sustainable and energetic needs, in order to update the building to the new efficiency requirements in terms of energy. Life cicle： We want to add a vision of life cycle to a building in terms of changing and updating. With this vision we are looking for ＂quality existing buildings＂ and for a way of designing ＂versatile frameworks＂ and layouts allowing for future renovation and refurbishments, Therefore our research is two pronged： （1） Identify examples of transformable buildings; （2） Looking for a design strategy that allows for easy changes of use.

A CONCEPTUAL FRAMEWORK FOR DELIVERING SUSTAINABLE BUILDING ENERGY EFFICENCY RETROFIT USING THE ENERGY PERFORMANCE CONTRACTING(EPC)IN CHINA

Sustainable building has become a future development trend in the building sector.Building Energy Efficiency Retrofit(BEER)provides excellent opportunities to reduce energy consumption in existing buildings,and to promote environmental protection,the rational use of resources,occupants’health,all of which helps to improve the sustainability of existing buildings.Energy Performance Contracting(EPC)provided by Energy Service Companies(ESCOs)is a market mechanism to provide financial and technological support for energy efficiency projects.This paper aims to develop a sustainability promotion framework for BEER projects under the EPC mechanism to link the sustainable performance of BEER with the success factors of this EPC mechanism.Different types of building have different energy consumption characteristics.This research focuses on hotel buildings in China.The paper develops a framework for sustainable BEER through an EPC mechanism in hotel buildings based on the EFQM Excellence Model for business quality management.Interviews were conducted with experts from the hotel industry,from energy service companies and with academics.Based on the developed framework,the study has identified 11 performance indicators for sustainable BEER and 28 success factors of an EPC mechanism.This provides significant groundwork for future study in developing an assessment model to evaluate the sustainability of BEER projects.

The Application of Computer Simulation Technology in Building Design

From the simulation software selection, meteorological data collection, model, boundary conditions, calculation setting and evaluation indicators, the paper summarize simulation method of wind, light and sound, summarize three kinds of environmental. The paper study on optimization analysis method of green building from four aspects of building orientation, architectural form, architectural layout and indoor environment, and puts forward the optimization scheme of the typical simulation analysis of simple questions; provide guidance for optimizing the design of green building. Finally, ECOTECT can adapt to the current domestic engineering design and consulting on green building simulation and design requirements, and has a broad application prospect.

Study on Energy Conservation of External Wall Structure of Rural Houses in Cold Area

According to the status of the northern rural architecture analysis, the prevalence of high energy consumption, low comfort features, it is essential to design energy-efficient buildings in rural areas. Article research and analyze the layout of rural buildings, a variety of energy-saving technologies and building design measures development and utilization of new energy sources and other issues that can make rural buildings to save energy and improve the environmental quality of living of farmers. It also put forward some reasonable suggestions for carrying out residential building energy efficiency in cold areas.

Analysis and Evaluation of Thermal-cooling Loads of Office Buildings Using Carrier Software in Iran

The importance and necessity of energy saving in the world have been dis­cussed for many years,but achieving a logical and transparent solution is still one of the main challenges and problems of the world’s economy.The rapid growth of energy consumption in the last two decades has caused the security of the domestic energy supply of buildings to face serious prob­lems.In this research,first by entering parameters such as the type of mate­rials,doors and windows,and the type of soil on the floor connected to the ground,etc.in the heat and cold load calculation software(HAP Carrier)as the design calculations and then in the second step entering the specifica­tions inferred from the Iran’s national building code as a reference for ener­gy saving calculations,calculations are performed and compared as the first criterion,and finally these two outputs are compared.The actual energy consumption and determination of the building energy consumption index are determined as another criterion,as well as the degree of deviation from the actual consumption.The results showed that the theoretical method and the thermal and refrigeration load calculations of the Zanjan Gas Company building have 6%difference in cooling load but the heating load is about 34%different,which means for cooling loads,the theoretical model can be used with high accuracy but for heating loads,the national building code needs fundamental changes.

Employing Computational Intelligence to Generate More Intelligent and Energy Efficient Living Spaces

Our living environments are being gradually occupied with an abundant number of digital objects that have networking and computing capabilities. After these devices are plugged into a network, they initially advertise their presence and capabilities in the form of services so that they can be discovered and, if desired, exploited by the user or other networked devices. With the increasing number of these devices attached to the network, the complexity to configure and control them increases, which may lead to major processing and communication overhead. Hence, the devices are no longer expected to just act as primitive stand-alone appliances that only provide the facilities and services to the user they are designed for, but also offer complex services that emerge from unique combinations of devices. This creates the necessity for these devices to be equipped with some sort of intelligence and self-awareness to enable them to be self-configuring and self-programming. However, with this ＂smart evolution＂, the cognitive load to configure and control such spaces becomes immense. One way to relieve this load is by employing artificial intelligence （AI） techniques to create an intelligent ＂presence＂ where the system will be able to recognize the users and autonomously program the environment to be energy efficient and responsive to the user＇s needs and behaviours. These AI mechanisms should be embedded in the user＇s environments and should operate in a non-intrusive manner. This paper will show how computational intelligence （CI）, which is an emerging domain of AI, could be employed and embedded in our living spaces to help such environments to be more energy efficient, intelligent, adaptive and convenient to the users.

Dynamic thermal performance and energy-saving potential analysis of a modular pipe-embedded building envelope integrated with thermal diffusive materials

In the context of racing to carbon neutrality,the pipe-embedded building system makes the opaque envelopes gradually regarded as the multi-functional element,which also provides an opportunity for thermal insulation solutions to transform from high to zero-carbon attributes.Based on the re-examination of the heat transfer process of conventional pipe-embedded radiant(CPR)walls,the modular pipe-embedded radiant(MPR)wall integrated with thermal diffusive materials is proposed to enhance the heat transfer capacity of CPR walls in the direction parallel to the wall surface,thereby forming a more stable and continuous invisible thermal barrier layer inside the opaque envelopes.A comprehensive thermal and energy-saving analysis study regarding the influence mechanism of several key factors of MPR walls,e.g.,the inclination angle of the filler cavity(θ-value),geometry size of the filler cavity(a:b-value)and thermal conductivity of the filler(λf-value),is conducted based on a validated numerical model.Results show that the dynamic thermal behaviors of MPR walls can be significantly improved due to that the radial thermal resistance in the filler cavity of MPR walls can be reduced by 50%,while the maximum extra exterior surface heat loss caused by the optimization measures is only 2.1%.Besides,a better technical effect can be achieved by setting the major axis of the filler cavity towards the room side,where the interior surface heat load/total injected heat first decreases/increases and then increases/decreases with the increase of theθ-value.In particular,the MPR wall withθL=60°can obtain the best performance when other conditions remain the same.Moreover,the performance indicators of MPR walls can be further improved with the increase of the cavity size(a:b-value),while showing a trend of rapid improvement in theλf-value range of 2–5λC and slow improvement increase in theλf-value range of 5–12λC.In addition,the improvement effect brought by optimizing theθ-value is more obvious as the a:b-value orλf-value increases.