Assessment of building cooling energy need through a quasi-steady state model: Simplified correlation for gain-loss mismatch

The objective of this work is to implement a simplified calculation procedure for building net energy need, based on a quasi-steady state model and on a monthly data set. In particular, it is intended to supply a formulation of the dynamic parameters and to adapt them to Italian climatic, typological, constructive and user data. The method was validated by determining the numerical correlations of the gain/loss utilization factor, through a comparison with a detailed building energy simulation software (EnergyPlus). The simulation was run on some test rooms defined by CEN (European Committee for Standardization) and on some real buildings that are representative of the Italian building stock, assuming weather data from different Italian locations (Torino, Roma, Palermo). The work shows that the accuracy of results is greatly affected by nonlinearities in the determination of the heat transfer and that the dynamic parameters are sensitive to some building features which are not taken into account in the CEN correlations.     

A Round Robin Test for buildings energy performance in Italy

The energy policy in Europe regarding buildings and the energy efficiency sector are regulated by two directives: 2002/91/CE - EPBD and 2006/32/CE - EEESD [1] and [2].The CEN has elaborated a standard to revise all European normatives about building energy performance and HVAC plants. The “CEN Umbrella” CEN/TR 15615 [3] includes a new version of EN ISO 13790:2008 [4] and a new standard about heating plant, use and contributions of renewable energy sources. Furthermore, the CEN Standard provides a software version for technicians.In this paper we present a Round Robin Test between a selection of softwares applied to an Italian case study. The selected calculation methodologies, range from research packages to extra-simplified software. Furthermore, the Italian procedure described in UNI TS 11300 [5] has been analyzed and considered as the reference for all other calculation methodologies.The results of the Round Robin Test show the relationship between thoroughness of data input and energy evaluation accurancy. The more the input data is affected by uncertainty, the less precise is the energy efficiency calculation. On the other hand the energy performance of building evaluation accurancy depends on the aim of the simulation: the energy audit, the energy design or the energy labeling (certification).     

Calculation of the yearly energy performance of heating systems based on the European Building Energy Directive and related CEN standards

According to the Energy Performance of Buildings Directive (EPBD) all new European buildings (residential, commercial, industrial, etc.) must since 2006 have an energy declaration based on the calculated energy performance of the building, including heating, ventilating, cooling and lighting systems. This energy declaration must refer to the primary energy or CO₂ emissions.The European Organization for Standardization (CEN) has prepared a series of standards for energy performance calculations for buildings and systems. This paper presents related standards for heating systems. The relevant CEN-standards are presented and a sample calculation of energy performance is made for a small single family house, an office building and an industrial building in three different geographical locations: Stockholm, Brussels, and Venice.The additional heat losses from heating systems can be 10-20% of the building energy demand. The additional loss depends on the type of heat emitter, type of control, pump and boiler.     

Quantification methods of technical building performance

A building performance assessment toolkit was developed for use by large corporate owners and building portfolio managers in the US. A variety of technical performance aspects are addressed such as energy, lighting, thermal comfort, maintenance and indoor air quality. Every assessment is based on a normative and objective Performance Indicator (PI). For easy data capture and calculation of PIs, the toolkit was implemented in a web hosted form, enabling facility managers and staff to collect the data during a walk-through enabled by PDA-based data entry. The current set of performance indicators is discussed and the results of the first benchmarks, most notably the energy benchmarks, are reported.     

公共建筑能效指标及评价方法现状分析

分析现行公共建筑能效指标及评价方法,按其对建筑用能效率的分析深度划分为全楼宇层面和系统层面,又将评估全楼宇能效的指标按照数据来源分为基于统计数据和基于模拟数据两大来源,而系统层面主要是针对暖通空调系统和照明动力系统的评价。随机选取上海4栋大型公建的实际数据来测评全楼宇能效定额评估法,结果显示其并不能理想地为挖掘节能潜力提供指导。如今国内公建能效评估体系较为不统一,应从各地区能效标准逐步修改、扩展,建立完善的评估体系。     

Comparison of the simplified methods of the ISO 13790 standard and detailed modelling programs in a regulatory context

The CEN standards that support the European Energy Performance of Buildings Directive requirement for calculation of the energy consumption of buildings allow various methods to be used for the same calculation. The impact of using the different methods within the updated ISO 13790 standard for space heating and cooling energy calculations was examined with a parametric analysis of a common building specification. The impact was assessed by considering the energy band, which would be assigned for the building based on the calculation results. The standard describes three different methods that can be used for the calculations: a monthly quasi-steady state method, a simplified hourly method and detailed simulation. For most cases studied, differences in the building rating given by the various methods were a maximum of one band. More significant differences were noticed in some cases. Parameter values in the monthly method were determined, which would lead to improved matching.     

建筑建造与运行能耗的对比分析

从建材含能和运输能耗出发,介绍了建造能耗的简化计算方法,并对目前我国住宅、普通办公建筑、大型办公建筑三类建筑建造能耗进行了案例分析。结果表明,三者的建造能耗平均水平分别约为3 850．5 500,7 300 MJ／m2,分别相当于各自8,13,9 a运行总能耗;钢材、水泥、混凝土、墙材为主要耗能用材。     

TEASER: an open tool for urban energy modelling of building stocks

The energy supply of buildings in urban contexts is undergoing significant changes. The increase of renewable sources for electrical and thermal energy generation will require flexible and secure supply systems. To reflect and consider these changes in energy systems and buildings, dynamic simulation is one key element. Sparse and limited access to detailed building information as well as computing time are challenges for building simulation on urban-scale. In addition, data acquisition and modelling for building performance simulation (BPS) are time-consuming and error-prone. To enable the use of BPS on urban-scale, this paper presents TEASER, an open framework for urban energy modelling of building stocks (open-source at https://github.com/RWTH-EBC/TEASER). TEASER provides an interface for multiple data sources, data enrichment and export of ready-to-run Modelica simulation models. The paper presents TEASER's methodology and package structure. Three use cases show TEASER's capabilities on the building, neighbourhood and urban scales.     

基于规范型建筑能耗模型对某建筑的节能分析

规范型建筑能耗模型是一种基于国际能耗规范对建筑能耗现状进行评价、分析的方法。相比于详细建筑模型软件(如Energy Plus),规范型建筑能耗模型具有建模快、速度快等优势。基于规范型建筑能耗模型,对中国石油大学(华东)某办公楼的能耗现状进行分析,并对节能方案进行评估。结果表明,规范型建筑能耗模型对于我国办公楼的能耗分析具有较好的应用前景。     

节能运行监管——我国大型公共建筑节能管理的必然选择

从我国大型公共建筑节能中存在的问题入手,分析总结了国外政府办公建筑和大型公共建筑的节能管理措施,并采用SWOT分析法充分论证了必须建立适应我国国情的新型节能管理制度——大型公共建筑节能运行监管体系。对节能运行监管体系的创新性进行了探讨。     

Building energy performance: sphere area as a fair normalization concept

ABSTRACT

Residential building energy performance indicators are compared with a different approach for the normalization of the characteristic yearly primary energy use. The purpose is to analyse which approach results in a fair assessment of more compact, energy-efficient building geometries, and of smaller building size. A normalization by floor area is shown to result in a poorer energy performance rating for smaller buildings. The notional building approach, as recently introduced in various countries, does not lead to a fair assessment of efficient geometries. Furthermore, the choice of reference characteristics to calculate the energy performance rating has a different impact on buildings with different characteristics. An average building approach is introduced as an improvement of the notional building approach. Form-efficient buildings are found to achieve a lower energy performance rating, but the choice of the reference characteristics is still present to a limited extent. As a second alternative, it is proposed to normalize the energy use by the sphere-area approach: the area of a sphere with the same volume as the rated building. This method leads to a fair assessment of form-efficient buildings and creates an incentive for more efficient building geometries and typologies.     

Evaluation of the corrected seasonal energy demand, for buildings classification, to be compared with a standard performance scale

In the European panorama, the relevant increase of the buildings energy consumptions has resulted, from the normative point of view (European directive 2002/91/EC [European Parliament and Council of December 16th, 2002 on the energy performance of buildings, Official Journal of the European Communities, L 1/65] and the relative national norms - for example Italian Decrees 192/05-311/06), in the imposition of minimum standards of construction, limiting the specific energy requirements specifically for heating and cooling. Moreover, in some countries it is being started to introduce, for buildings that respect the minimum performances levels imposed, incentive and defiscalization measures, function of their particular energetic efficiency and the corresponding performance class.Therefore, to compare the construction quality of different buildings, through energy performance classification, the authors propose a procedure for the determination of the corrected energy demand, separately for heating and cooling, independent of buildings location and directly comparable to a standard seasonal performance scale, defined on the entire territory of application.The procedure is so developed through simulation on a wide range of case-studies and then tested on a different buildings set: its effectiveness results in the attribution to each building test of an univocal performance class, providing an energy performance evaluation not affected by the building localization.     

上海地区办公建筑能耗的简化评价方法

针对既有办公建筑能耗评价方法,使用建筑“能效当量能耗”这一统计量来评价建筑能源使用情况,因为在“能效当量能耗”的计算过程中剔除了与能源使用效率无关因素的影响,评价结果更加客观.但既有方法需要获得详细的建筑信息,制约了其适用性.根据一定限制条件下既有方法的评价结果与应用单位面积能耗得到的评价结果之间的相似性,提出简化的能...     

各国规程关于圆钢管混凝土构件刚度计算方法的介绍与比较

详细地介绍了美国AISC LRFD( 99)规程、欧洲Eurocode 4 (EC4 - 94 )规程、日本AIJ规程以及中国JCJ0 1- 89规程、CECS2 8:90规程、DL T 5 0 85 - 1999规程中有关圆钢管混凝土构件刚度的计算方法。通过对比不同的计算公式 ,对上述各国规程中的刚度计算公式的建立思想与方法进行分析和说明     

Assessing scalability of a low-voltage distribution grid co-simulation through functional mock-up interface

State-of-the-art Modelica tools for modelling and simulating multi-physical systems have reached certain maturity among the building physics community. Hence, simulation is widely used for control, sizing and performance assessment of energy systems. However, serious efficiency issues arise for large-scale models. This article proposes a practical application of co-simulation methods on detailed district energy systems. The aim of this study is to assess performance and scalability of co-simulation through functional mock-up interfaces on a detailed and multi-physical district model. In particular, we propose a comparative analysis between classical simulation and co-simulation methods and a scalability analysis on a growing number of buildings. The models have been implemented using Modelica language and the OpenIDEAS library. A decomposition approach is taken for modelling the entire system, while stochasticity in the inputs is taken into account. Results are presented for various integration scenarios, including a classical integrated simulation for reference and co-simulations involving different master-algorithms within Dymola and DACCOSIM 2017. Scenarios are compared in terms of speed-up and accuracy of principal physical quantities representing key performance indicators such as indoor temperature, current and voltage at building's connection. The analysis shows that co-simulation can run up to 90 times faster than the integrated simulation for 24 buildings, while ensuring acceptable accuracy.     

Influence of climate change on the energy efficiency of light-weight steel residential buildings

This paper addresses the influence of the climate change scenarios predicted by the Intergovernmental Panel for Climate Change (IPCC) for Southern Europe and the Mediterranean region on the energy efficiency of light-weight steel residential buildings. A performance-based approach is adopted to carry out this assessment using advanced dynamic simulation of the operational energy performance. Based on a typical Portuguese cold-formed steel residential building, a representative numerical model is calibrated against normative requirements for dynamic simulation of thermal behaviour and sophisticated computational fluid dynamics models. Considering climate change scenarios predicted by the IPCC, a parametric study is carried out to assess the influence of climate change on the energy efficiency of light-weight steel residential buildings representative of a warm temperate summer dry climatic region.     

Building typologies as a tool for assessing the energy performance of residential buildings - A case study for the Hellenic building stock

Successful strategies towards minimizing the energy consumption and greenhouse gas emissions attributed to the building sector require knowledge on the energy-related characteristics of the existing building stock. Despite the numerous studies on energy conservation applications in buildings, current knowledge on the energy-related characteristics of the building stock still remains limited. Building typologies can be a useful instrument to facilitate the energy performance assessment of a building stock. This work is based on a harmonised structure for European building typologies (TABULA) developed for residential buildings, but the methodology may be extended to the tertiary sector as well. National typologies are sets of model buildings with characteristic energy-related properties representative of a country's building stock. The model buildings are used as a showcase for demonstrating the energy performance and the potential energy savings from typical and advanced energy conservation measures (ECMs) on the thermal envelope and the heat supply system. The proposed Hellenic residential building typology is presented for the first time along with an assessment of various ECMs that are used for an estimate of the energy performance of building stock in Greece in an effort to meet the 9% indicative national energy savings target by 2016.     

绿色奥运建筑评估体系围护结构节能评估研究及指标确定

综合分析了目前建筑围护结构节能设计标准的研究现状。研究并建立了绿色奥运建筑评估体系围护结构节能评估方法，对不同类型建筑根据其建筑本身及使用特点采用不同的评估方法，通过模拟计算确定了住宅建筑、商业建筑及体育场馆建筑的具体评估指标。     

Assessing energy performance in the latest versions of Hong Kong Building Environmental Assessment Method (HK-BEAM)

The latest (4/04 and 5/04) versions of the Hong Kong Building Environmental Assessment Method (HK-BEAM), one covering new buildings and the other existing buildings, have been formally launched in 2005. The paper describes the building energy performance assessment method in these latest HK-BEAM versions. With the use of the energy budget approach, the assessment framework is applicable to a wide range of buildings that may comprise different mixes of premises types. The new scheme provides bonus credits for provisions that allow utilization of renewable energy sources. For existing buildings, it makes allowances for plant performance degradation and constraints to implementation of improvement measures in existing buildings. So far, the new assessment method has been applied to six building developments, including commercial complexes and residential developments. The assessment results are presented and discussed in the paper.     

Design strategy for low-energy ventilation and cooling within an urban heat island

Natural ventilation is a proven strategy for maintaining thermal comfort in non-domestic buildings in the UK. The energy consumption and thus the carbon dioxide emissions that contribute to global warming are lower than in conventional air-conditioned buildings. However, the ambient temperatures in the UK have risen over the last decade and new climatic data for use in the design of naturally ventilated buildings has been published. Using these data and dynamic thermal modelling, it is shown that passive stack ventilation alone was unlikely to maintain summertime comfort in a proposed University College London building within an urban heat island. The stack ventilation strategy was evolved by the introduction of passive downdraught cooling. This low-energy technique enables cooled air to be distributed throughout the building without mechanical assistance. The underlying principles of the technique were explored using physical models and the anticipated performance predicted using thermal modelling. The architectural integration is illustrated and the control strategy described. The resulting building is believed to be the first large-scale application of the passive downdraught cooling technique; construction began in late 2003.