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.

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.

A PARAMETRIC STUDY OF THE ENERGY EFFICIENCY OF EXISTING AIR-CONDITIONED BUILDINGS IN KUWAIT

In Kuwait air-conditioning systems consume approximately 70%of the grid energy during the long summer months.In this paper,various practical approaches are investigated to enhance the energy efficiency and decrease the energy consumption of five existing air-conditioned(AC)buildings in Kuwait City.The process of energy management in air-conditioned buildings in Kuwait is overwhelming due to high energy consumption in the building sector.This study proposed an optimization technique for the proper energy management of installed AC systems to target energy-efficient buildings.In this study the aim is to explore the effect of different operating parameters,both theoretically and experimentally,and to contribute to the reduction of AC energy consumption.Consequently,the relationship between the thermal load in the air-conditioned buildings and the actual electrical energy consumption is determined,and remedial measures,along with different recom-mendations for energy saving,are presented.The actual thermal loads of each selected building were calculated and compared with the installed cooling capacity of the AC systems.From the results obtained it was concluded that,by implement-ing the suggested remedial measures,the predicted load in the selected buildings could be decreased significantly from the existing installed capacity of the cooling systems.Most of the remedial measures suggested for energy management lead to a reduction in power consumption and increased energy efficiency at different levels based on the specifications of the buildings considered and the AC systems installed,resulting in improved in economy,a reduced carbon footprint,and a cleaner environment.

A COMPARATIVE STUDY:DESIGN STRATEGIES FOR ENERGY-EFFICIENCY OF HIGH-RISE OFFICE BUILDINGS

Tall buildings are being designed and built across a wide range of cities.A poorly designed tall building can tremendously increase the building’s appetite for energy.Therefore,this paper aims to determine the design strategies that help a high-rise office building to be more energy efficient.For this purpose,a comparative study on twelve case buildings in three climate groups(temperate,sub-tropical&tropical)was performed.The exterior envelope,building form and orientation,service core placement,plan layout,and special design elements like atria and sky gardens were the subject of investigation.effectiveness of different design strategies for reducing the cooling,heating,ventilation and electric lighting energy usage.Finally,lessons from these buildings’were defined for the three climates.Furthermore,a compari-son of building energy performance data with international benchmarks confirmed that in temperate and sub-tropical climates sustainable design strategies for high-rise buildings were performing well,as a result leading to lower energy consump-tion.However,for the tropics the design of high-rise buildings needs additional consideration.

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.

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.

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.

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.

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.

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.

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.

RISK FRAMEWORK FOR ENERGY PERFORMANCE CONTRACTING BUILDING RETROFITS

Energy performance contracting(EPC)has emerged as a useful project financ-ing and delivery tool for building retrofits,particularly among building owner-ships which have experienced reduced funding for capital projects.Through EPC,a contractor(called the EPC contractor or the energy service company)guaran-tees minimum energy savings performance and enables the building owner to finance the project using utility savings over the length of the project(which is typically 12-15 years,or longer).Despite its growing use,there is a dearth of lit-erature regarding a contractor’s risks related to the delivery and execution of EPC building retrofits.This is particularly important as the performance guarantee effec-tively transfers project performance risk from the owner to the EPC contractor.This research proposes a project factors-based risk framework for EPC building retrofits,initially developed through a comprehensive review of relevant literature and project documents and refined through the elicited expertise of 19 highly expe-rienced EPC contracting professionals.A Delphi technique-based expertise elici-tation strategy was used to confirm the findings of the a priori(literature-based)framework and provide additional analysis related to risk causes and control mea-sures as well as relative risk importance.This information was used to construct a refined risk framework which provides insight into the lengthy project performance period during the earliest phases of the project’s life cycle.This has the advantage of providing rapid screening of the project factors that can potentially lead to the greatest project performance risks.

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.

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.

DEVELOPING STANDARD WINDOW TO FLOOR RATIO(WFR)SYSTEM FOR GREEN RESIDENTIAL BUILDINGS IN SUBTROPICS

The window system is generally regarded as the most vulnerable building system for the indoor energy performance of green buildings.Window systems are given sig-nificant attention by architects and engineers,especially in areas with long summer and high solar radiation such as the subtropics.This study aims to develop a standard window-to-floor ratio(WFR)system for green residential buildings in the subtrop-ics.Using Autodesk Revit as the interface,a real high-rise residential building was digitalized and imported into Ecotect for energy consumption analysis.Comparative analyses were conducted to determine the optimal WFR for building energy effi-ciency.Results demonstrated 0.23 as the optimal WFR in Xiamen,one of the typical subtropical cities in Asia.Furthermore,accompanied by a four-sidefins sunshade device and a double glass window(DGW)with clear“glass+air gap+reflective”glass,the building energy consumption was further reduced by 34.47%compared to the initial model,which successfully met the optimization target of 30%,set according to the green building standard.The results of this study are helpful to architects and building engineers when designing or retrofitting green buildings as we provide specific support for design features for energy performance.

ECOLOGICAL PAYBACK TIME OF AN ENERGY-EFFICIENT MODULAR BUILDING

Ecological payback time was calculated for demolishing an existing commercial building with average energy performance and replacing it with an energy-efficient,prefabricated building.A life-cycle assessment was performed for a 5,000 ft2 commercial building designed by Project Frog and prefabricated in San Francisco,California,and compared to the impacts of annual energy consumption and continued status quo operation of a comparable average commercial building.Scenarios were run both with and without rooftop solar panels intended to make the prefabricated building net zero energy.The analysis considers the materials and manufacturing,transportation,annual energy use of the new building,and disposal of the existing building,compared to continued annual energy use of the existing building.The carbon payback of a new building with no solar against operation of an existing commercial building was found to be roughly eleven years,and a building with enough rooftop solar to be net zero energy was roughly 6.5 years.The full EcoIndicator99 environmental impact payback for a new efficient building with no solar was found to be twenty years,and a solar net-zero building was roughly eleven years against operation of an existing commercial building.

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.