Economics and the selection and development of energy standards for buildings

Energy-conservation standards for new buildings will play a major rôle in federal and state conservation policies in the coming decade. This article discusses economic-efficiency considerations that can be incorporated into the selection and development of such standards. Three types of energy budgets — ‘fixed energy budgets’, ‘partially variable energy budgets’, and ‘economically efficient energy budgets’ (EEEB) — are examined for use as standards. Economic-efficiency criteria are presented for use in selecting an appropriate energy budget. An illustrative example shows the potential dollar losses in life-cycle terms from failing to apply an EEEB. Research and operational requirements for developing and implementing an energy budget are described. Three energy-budget standards are evaluated in terms of economic efficiency, administrative feasibility, equity, and consistency in design requirements. An EEEB appears optimal in that it ranks highest overall with respect to the four criteria. Failure to begin research for, and development of, EEEBs now would impose unnecessary social costs in the form of extra expenses to achieve any chosen target levels of energy conservation in buildings.     

Resource Impact Factors and optimal energy concervation standards for buildings

The effects of using “Resource Impact Factors” (RIFs) in the determination of an optimal energy conservation performance standard for buildings are assessed. RIFs may be generally defined as indices constructed to reflect the full social costs of using various energy types. The major elements which RIFs should take into account are discussed as well as the appropriate method of formulating them. A cost minimization model for determining the optimal standard is used in conjunction with a range of RIF values so that a comparison can be made between a standard that is optimal from the private point of view (without RIFs) and one that is optimal from the social point of view (with RIFs). The comparison is made in terms of the amount of energy saved by each standard in climates of differing severity.     

Assessment of natural cooling potential for buildings in different climatic conditions

Several methods of achieving cooling in buildings in hot climates have been developed in recent years. One such method, roof sack-cloth cooling, relies on maintaining a thin film of water on the roof. In the present article, a method of assessing the suitability of a given climatic condition for natural cooling is presented. This method is then applied to predict the performance of a roof sack-cloth cooling technique to certain hot-dry and hot-humid locations in India.     

住宅能源消费结构及自然能源应用

通过大量的数据说明了我国住宅建筑中的能源消耗情况，指出住宅建筑中能源消费结构不合理以及带来的环境污染与CO2气体排放等严重的负面影响。通过对国内外住宅中以太阳能为主的自然能源利用技术的发展和实际应用情况的比较性分析，指出在住宅中以自然能源与可再生能源代替传统能源的优越性和发展的必然趋势，以及国内住宅在自然能源利用方面的不足，同时对我国住宅中自然能源利用技术发展提出了对策与展望。     

Making method and application of standards for energy consumption quota of civil buildings

Based on the energy consumption survey in Wuhan, the paper provides the civil building energy consumption quotas according to the three energy efficiency indicators, which include the limit value, the admission value and the advanced value. The paper also presents the uses of different energy consumption quotas and analyses the difference between them. Adopting a statistical analysis method, the paper analyses the limit values of 39 kinds of building using SPSS software. Adopting a simulation method and a device isolation method, the paper provides 15 kinds of admission values and advanced values using DeST simulation software based on energy efficiency design standards. The paper also analyses that judging and excluding outliers are the basis for accurately formulating energy quotas. According to the building energy efficiency and fair principle, the paper gives unit building area energy consumption indicators for buildings with 39 kinds of different functions, air conditioning and heating energy consumption accounts for the proportion of building energy consumption, the limit values of energy consumption indicators of annual per capita energy consumption, per household, per bed, per student which are concerned with building function and standard deviations of the limit values.     

中美节能标准中办公基准建筑的能耗比较

对比了中美两国节能标准,以上海地区某办公楼为例,分别建立了在中美公共建筑节能标准下的基准建筑模型,按照ASHRAE 90.1对能耗模拟的要求进行计算,得到该办公楼的空调系统能耗和总能耗.结果表明,我国标准在围护结构、机组效率方面的要求均低于ASHRAE 90.1标准,但是由于美国的空调系统因控制湿度而导致再热量增加,所以根据我国标准和ASHRAE 90.1计算出来的办公建筑的平均能耗强度基本一致.建议我国标准适当减小围护结构的传热系数,提高机组的性能,以利于节能;并且,应详细规定能耗模拟原则,以减少能耗模拟结果的人为因素.     

建筑物被动冷却与混合冷却的方法

建筑物采用自然方法冷却是应建筑节能、改善室内外环境质量的要求而产生和发展的，其总的思路是习量防止建筑得热和利用自然环境作为热汇进行散热。在文献调研的基础上简要综合地主人了生发于这一思路的种种方法。     

A new methodology for the design of low energy buildings

The Kyoto protocol binded the developed countries to reduce the greenhouse gas emissions at least by 5% by 2008-2012 in order to tackle global warming and climate change. Some of the measures of the governments to achieve this goal are to promote new buildings construction and to retrofit existing buildings while satisfying low energy criteria. This means improving energy efficiency of buildings and energy systems, developing sustainable building concepts and promoting renewable energy sources.The design of a low energy building requires parametric studies via simulation tools in order to optimize the design of the building envelope and HVAC systems. These studies are often complex and time consuming due to a large number of parameters to consider. Hence, this paper aims to set up a methodology that simplifies parametrical studies during the design process of a low energy building. The methodology is based on the Design of Experiments (DOE) method which is a statistical method widely used in industry to perform parametric studies that reduces the required number of experiments.     

Multivariate optimization of design trade-offs for solar low energy buildings

The large number of different design options available for energy conscious building design calls for careful quantitative assessments to find the optimum technology mix for each project. Here, a numerical multivariate optimization procedure is introduced, to draft the optimum building design variables at an early design stage. The approach is based on integrating a non-linear optimization scheme with building modeling, whereby the basic physical, technical and economic interactions between the building design options and energy flows are accounted for. The optimization tool developed then finds the economic optimum, given the project-specific boundary conditions and the energy consumption target. The applicability of the approach is demonstrated through a set of case studies.     

我国建筑节能设计标准编制思路与进展

介绍了我国严寒、寒冷地区，夏热冬冷地区及夏热冬暖地区居住建筑节能设计标准规定性指标与国外相关标准的差别及其编制思路和特点，简要介绍了正在编制的公共建筑节能设计标准的编制思路。介绍了美国相关建筑节能标准ASHRAE／IESNA Standard90．1-2001的有关内容。从建筑节能标准体系和建筑节能标准内容及标准规定的设计方法等方面，对两国节能标准进行了比较，指出了美国建筑节能标准的可借鉴之处。     

Analysis of annual heating and cooling energy requirements for office buildings in different climates in Turkey

A great amount of world energy demand is connected to the built environment. Electricity use in the commercial buildings, accounts for about one-third of the total energy consumption in Turkey and fully air-conditioned office buildings are important commercial electricity end-users since the mid-1990s. In the presented paper, the interactions between different conditions, control strategies and heating/cooling loads in office buildings in the four major climatic zones in Turkey – hot summer and cold winter, mild, hot summer and warm winter, hot and humid summer and warm winter – through building energy simulation program has been evaluated. The simulation results are compared with the values obtained from site measurements done in an office building located in Istanbul. The site-recorded data and simulation results are compared and analyzed. This verified model was used as a means to examine some energy conservation opportunities on annual cooling, heating and total building load at four major cities which were selected as a representative of the four climatic regions in Turkey. The effect of the parameters like the climatic conditions (location), insulation and thermal mass, aspect ratio, color of external surfaces, shading, window systems including window area and glazing system, ventilation rates and different outdoor air control strategies on annual building energy requirements is examined and the results are presented for each city.     

Predictive control techniques for energy and indoor environmental quality management in buildings

The aim of the present paper is to present a model-based predictive controller, combined with a Building Energy Management System (BEMS). The overall system predicts the indoor environmental conditions of a specific building and selects the most appropriate actions so as to reach the set points and contribute to the indoor environmental quality by minimizing energy costs. The controller is tested using a BEMS installation in Hania, Crete, Greece.     

Thermally acceptable temperature drifts can reduce the energy consumption for cooling in office buildings

The energy consumption and cost in large office buildings can be reduced by allowing the indoor environment to deviate from the optimum comfort conditions to situations which are still acceptable by most occupants. One such strategy is to allow the indoor temperature to increase in the afternoon in summer. A computer program was developed to predict the thermal sensation and discomfort under transient conditions, and the detailed computer program BLAST was used to evaluate the indoor temperature, space cooling load, chilled water consumption and seasonal energy use. This paper presents a comparison performed for a reference office building in Montréal between a conventional design, with constant set-point temperature during the operating hours, and a new design, where the indoor temperature is allowed to increase after 3:00 p.m. The results show a reduction of seasonal consumption for chilled water between 34 and 40%, and a reduction of energy budget for HVAC systems of 11%.     

我国城镇住宅夏季空调能耗状况分析

根据调查和计算,利用模拟归纳法对我国城镇住宅夏季空调能耗状况进行了定量分析.结果表明,目前我国城镇住宅夏季空调的总体能耗水平较低,但增速较快,且不同气候区之间差异较大.2005年全国城镇住宅夏季空调总耗电量约为285亿kwh,平均耗电指标约为2.65 kWh/m2.我国城镇住宅空调能耗前4位的地区是:广东、浙江、江苏和湖北,它们的空调总能耗约占全国城镇住宅空调总能耗的51.8%,广东、福建、重庆、浙江、上海、湖北、江苏和广西的空调能耗指标较高,它们是我国城镇住宅空调节能的重点地区.     

Thermal effectiveness characteristics of low approach indirect evaporative cooling systems in buildings

Meteorological enthalpy analysis of temperate and maritime climates above latitude 45°N suggests that the water-side evaporative cooling technique has considerable unrealised potential with contemporary “high temperature” building cooling systems—such as chilled ceilings and displacement ventilation. As low approach conditions are the key to exploiting the cooling potential of the ambient air, thermal performance at such conditions needs to be investigated. To address the research issues, an industrial scale test rig, based on a low approach open cooling tower and plate heat exchanger and designed to maximise evaporative cooling potential, has been constructed.     

Elaboration of energy saving renovation measures for urban existing residential buildings in north China based on simulation and site investigations

It is necessary to determine whether to implement a retrofit measure or not based on its energy saving and economic benefits, when conducting a retrofit project. The common way to do that is to set up a building simulation model and calculate its energy saving and economic benefits. Because of the great discrepancy between the actuality and the building simulation model, it is very important to use the factual energy use to calibrate the model, so as to accurately predict the benefits of retrofit measures. Although the energy efficiency retrofit of residential buildings in north China is implemented in a large scale, it seldom knows whether the commonly used retrofit packages are optimized. Therefore, a typical residential building is selected in Beijing, and the energy saving and economic benefits of different retrofit measures are analyzed using a simulation model calibrated with its actual space heating energy use, and the optimized retrofit packages are put forward. Results shows the retrofit of space heating system is a very attractive measure due to its relatively low investment but good energy saving benefit, and roof retrofit is also cost effective, while window retrofit and wall retrofit are not economic to conduct separately. Four optimized retrofit packages are figured out to realize the 50% and 65% reductions of space heating intensity required in the energy efficiency standards, which have less investment costs compared with currently widely used packages, and the retrofit packages for the 65% reduction is more cost-effective than the packages for the 50% reduction.     

Drivers of moderate increase in cooling energy use inresidential buildings in Hong Kong

Increase in cooling energy usage of the residential sector in Hong Kong has been moderate in the most recent ten years(2004-2013).Factors and drivers responsible for this are of interest to policy makers in search of performance improvement but such information is not available in extant literature.This paper reviews the policy instruments introduced in Hong Kong during this period of time and examines the different engineering factors contributing to improvements in cooling energy efficiency.Whether the policy instruments have been instrumental in bringing about changes in engineering design and thus improvement in cooling energy efficiency is evaluated on the basis of the equipment and building envelope characteristics of 64 residential developments in Hong Kong.Different statistical analyses reveal that the use of more energy efficient room air-conditioning units(COP),smaller window-to-wall ratios(WWR)and walls with higher U-values are the engineering factors(WallU)that have contributed to moderation of growth of energy consumption;these were driven by policies introduced by the Hong Kong Government.Regarding the sensitivity of the three engineering factors,it was found that COP was the highest amounting to 0.455,followed in descending order by Wal-1U and WWR.Their sensitivities were 0.289 and 0.006,respectively.     

A nomograph for estimating annual cooling and heating energy requirements in buildings dominated by internal loads

This paper describes a nomograph that can be used as a design tool for estimating annual cooling and heating coil loads in interior zones of office buildings. Based on simplified relationships between the heat load on an air-conditioning system, internal heat generation and outdoor air intake rate, the equations for normalized anuual cooling and heating coil loads in interior zones of office buildings are derived as a function of outdoor air enthalpy, two variables related to the intensity of internal cooling load, and the minimum and maximum outdoor air intake rates. Normalization of heat load on an ari-conditioning system made it possible to construct a design nomograph which can be used to calculate the energy-saving effects of an economizer cycle (passive cooling with ventilation air) and an exhaust air heat recovery unit on annual cooling and heating coil loads at the schematic design stage.Example calculations using the nomographs for three locations in Japan show that the energy-sacing effects of economizer cycle and exhaust air heat recovery units are heavily dependent on the profiles of regional weather conditions. A validation study showed that annual cooling and heating coil loads estimated from the nomographs were in good agreement with those from a detailed computer-based calculation.     

Assessment of energy and natural resources conservation in office buildings using TOBUS

The potential for optimum energy use and conservation of natural resources in representative southern and northern European office buildings is evaluated using the new European TOBUS methodology and software for office building refurbishment. Various scenarios are being accessed for energy and water conservation in office buildings. The proposed retrofit actions focus in the areas of space heating and cooling, artificial and natural lighting, service hot water, office equipment, elevators and sanitary water. The resulting conservation and related costs are taken into account in order to help the auditor classify the retrofit actions for an audited building. The TOBUS methodology and tools have been implemented to study four Hellenic office buildings and two from Denmark in order to demonstrate the applicability of the overall approach. Energy conservation in Hellenic and Danish buildings range for space heating from 5 to 71 and 0.5 to 6%, for space cooling from 1 to 38 and 4 to 20%, for artificial lighting from 40 to 53 and 26 to 62%, for office equipment from 13 to 62 and 13 to 87% and for elevators at 35 and 23%, respectively. Sanitary water conservation can reach 74% in all audited buildings.