Influence of building parameters and HVAC systems coupling on building energy performance

The performance of different HVAC systems varies when coupled with different buildings. This paper examines the relationship between building heating and cooling load and subsequent energy consumption with different HVAC systems. Two common HVAC systems in use throughout the UK office building stock, variable air volume (VAV) system and fan coil (FC) with dedicated outside air system, have been coupled with a typical narrow plan office building with and without daylight control and for both cellular and open plan.The results presented in this paper clearly indicate that it is not possible to form a reliable judgment about building energy performance based only on building heating and cooling loads. For the two investigated systems, variable air volume system and fan coil with dedicated outside air system, the difference between system demand and building demand varied from over −40% to almost +30% for cooling and between −20% and +15% for heating. If a heat recovery unit is used, the difference in heating performance is even greater, rising to −70%.     

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.     

干盘管技术在办公类建筑中可实施性的静态分析

本文针对干盘管技术在办公类型建筑中的应用,静态分析了以下两个方面：人均新风量取值对新风系统的影响;人均新风量取值对风机盘管系统的影响。根据上述分析的结果,讨论了在办公类型建筑中应用干盘管技术存在的三大问题：人均新风量的取定问题;新风再热过程中能量回收问题;干盘管技术中冷冻除湿方法的应用问题。从而揭示了干盘管技术在办公类型建筑中的可实施性。     

用EnergyPlus模拟检验影响节能办公建筑的因素

本文根据《公共建筑节能设计标准》(GB 50189-2005)对办公建筑的相关规定,运用全能耗模拟软件EnergyPlus对北京等城市节能办公建筑的逐时冷热负荷进行了模拟,得出了不同外墙传热系数、不同建筑朝向和过渡季节通风换气次数等对室内进行全年负荷的影响并对其进行了分析,认为从节能角度讲,外墙传热系数存在合适值而不应盲目减小、既定建筑物存在最佳朝向、过渡季通风可消除室内多余的热量但实际应用中应因地而异,从而为节能办公建筑的设计、建造等提供有益的参考。     

Opportunities for reversible chillers in office buildings in Europe

Europe with more than 600 millions of square meters of air-conditioned office buildings offers an opportunity to save energy and reduce CO₂ emissions by reconverting chillers into reversible heat pumps in office buildings. One of the questions asked in the framework of the IEA ECBCS Annex 48 is how to assess the energy saving potential and how to identify the most interesting building cases. The methodology proposed here is based on the simulation of office buildings representative of the building stock. The energy consumption has been simulated for different office building types in five European climatic zones on the one hand with boilers for heating and chillers for cooling, and on the other hand with reversible chillers plus back-up boilers. The results of the simulations in terms of energy consumption allow us to assess the primary energy savings and CO₂ emission reduction in Europe by reconverting chillers into reversible heat pumps. The results show that the potential of annual primary energy savings and annual CO₂ emission reduction are about 8 TWh_PE and 3 millions of tons of CO₂ in Europe-15. Even if the temperature level in terminal units can be solved using the cooling coil instead of the heating coil, a back up boiler turns generally out to be required for the coldest days in the year or when simultaneous heating and cooling demands occur.     

Applicability and optimum control strategy of energy recovery ventilators in different climatic conditions

Energy recovery ventilators (ERVs) transfer energy between the air exhausted from building and the outdoor supply air to reduce the energy consumption associated with the conditioning of ventilation air. In this paper, the applicability of ERVs with sensible and latent effectiveness values in a practical range is studied using TRNSYS simulation program. The impact of ERV on annual cooling and heating energy consumption is investigated by modeling a 10-storey office building in four American cities as representatives of major climatic conditions. The results show that heat and moisture recovery can lead to a significant reduction in the annual heating energy consumption (i.e., up to 40%, which is 5% higher than heat recovery). Also, an ERV with the capability of moisture recovery may reduce the annual cooling energy consumption by 20% provided the ERV is properly controlled. Since the un-controlled operation of ERVs during the summer may increase the cooling energy consumption, an optimum control strategy is developed and verified in the paper. This optimum control strategy depends on ERV's latent to sensible effectiveness ratio. For instance, an ERV with equal sensible and latent effectiveness should be operated when either the outdoor enthalpy or temperature is greater than that of the indoor air.     

夏热冬暖地区公共建筑空调排风热回收模式探讨

本文分析了夏热冬暖地区公共建筑空调新风负荷特征,研究了不同排风热回收模式下的节能效果。结果表明,当采用全热回收模式时,新风负荷降低60％以上,建筑空调冷负荷降低18％～23％;而采用显热回收模式时,新风负荷降低5％-20％,建筑空调冷负荷仅降低8％。可见,夏热冬暖地区公共建筑空调排风全热回收模式具有较好的节能效益。     

北京金融街B7大厦暖通空调设计

介绍了冷热源、供暖、空调、通风及防排烟、控制等系统的设计。办公区采用四管制、变风量系统加散热器供暖系统,且内外区共用同一机组;四季花厅和大堂等大空间采用低温地板辐射供暖系统;大部分百叶风口设在室外绿地地面上,在进排风竖井里进行了消声、过滤、防水、排水处理;新风不作冷热湿处理,直接送入空调机组;空调系统变频节能运行。     

夏热冬冷地区办公建筑降低供暖空调能耗的技术路径

以上海地区某办公建筑为例,基于EnergyPlus能耗模拟,探讨了围护结构性能提升和暖通空调系统优化这2条节能技术路径对夏热冬冷地区办公建筑降低供暖空调全年能耗的有效性.结果 表明:围护结构性能提升的节能潜力较小,经济性较差;单纯提高围护结构保温隔热性能并不能保证降低建筑年耗冷量,应综合分析全年供热供冷能耗确定围护结构...     

室内恒温泳池综合节能方案研究

基于广州某会所室内恒温泳池的温湿度设计参数,计算了该泳池全年制冷、除湿、泳池加热和采暖负荷动态需求。通过分析动态冷热负荷曲线提出冷凝热回收应作为泳池综合节能方案的基本出发点,进一步比较了泳池专用热泵系统与全热回收风冷热泵系统两种方案的运行特点和全年能耗特性,并建议采用小型热回收型热泵系统与普通风冷热泵的组合方案。     

鼎好电子商城暖通空调设计

简要介绍了鼎好电子商城空调系统和防排烟系统的设计,商城采用了风机盘管加新风空调系统和二次泵空调水系统。从空调方式及空调水系统形式的选择、排烟系统的设置和空调冷负荷的确定等方面对大空间商业建筑空调设计进行了总结。     

空调设备排热对传热、新风冷负荷的影响

建立了室内外热环境耦合计算模型。通过实地测量,验证了模型模拟结果的准确性。采用该模型,以某典型办公建筑群为研究对象,探讨了空调设备排热对传热冷负荷及新风冷负荷的影响。空调设备排热加大了传热冷负荷及新风冷负荷,对新风冷负荷的影响更为显著。     

Development of dual-source hybrid heat pump system using groundwater and air

To achieve high heat pump efficiency, groundwater heat pump (GWHP) system uses groundwater, which is relatively stable AT temperature compared with outdoor air, as a heat source. However, it is difficult to meet annual heating and cooling loads using only groundwater as a heat source. In order to optimize the operation method of GWHP systems, it is necessary to develop a system utilizing both groundwater and air sources according to the building load conditions. Furthermore, during intermediate seasons (such as spring and autumn) with reduced heating and cooling loads, GWHP system is less efficient than air source heat pump (ASHP) system according to temperature conditions. In order to more efficiently use GWHP systems, it is necessary to develop a system which utilizes both groundwater and air sources according to temperature conditions and building loads. This research has developed a GWHP system that employs a hybrid heat pump system with groundwater wells using dual groundwater and air heat sources. In this paper, the annual performance of the developed system has been calculated, and several case studies have been conducted on the effect of introduction location, refrigerant and pumping rate. Furthermore, the coefficient of system performance and the effects on underground environments have been evaluated by real-scale experiment using two wells.     

某夏季干热地区办公大楼报告厅夏季空调设计

以新疆某办公大楼报告厅空调系统设计为例,分析了夏季干热气候区室外空气设计参数的特殊性。着重介绍了变制冷剂多联机+全热交换系统、风机盘管+新风系统、一级蒸发冷却系统、二级蒸发冷却系统及采用屋顶全新风机组,并结合本项目对这几种不同的空调系统进行分析与比较,确定了适合本项目的空调系统形式。     

北京国典大厦空调设计

该大厦是一座以商务办公为主的写字楼,对大厦的空调水系统、风系统、供暖系统、气流组织、防排烟系统和DDC自动控制系统的设计作了介绍;详细介绍了空调冷热源的选择,阐述了办公类建筑的暖通空调设计;简单介绍了公共建筑中厨房排风、排烟系统的设计,并对设计中的一些经验和教训进行了总结。     

Energy saving in buildings by using the exhaust and ventilation air for cooling of photovoltaic panels

A building integrated photovoltaic-thermal (BIPVT) setup has been developed for using the cooling potential of ventilation and exhaust airs in buildings for cooling the photovoltaic (PV) panels and also heating the ventilation air by heat rejection of PV panels. The setup has been tested numerically for the Kerman city located in Kerman province in the south of Iran. Results showed that, the exhaust and ventilation airs in heating ventilating air conditioning systems can be used as the cooling fluid of the PV panels and increase their efficiency. On the other hand, the heat rejection of the PV panels could provide some part of the ventilation air heating load.     

上海某办公建筑空调系统分析及节能研究

上海地区属于夏热冬冷地区,办公楼建筑大量使用玻璃幕墙,这使得办公建筑空调冷负荷增大。本文结合实际工程,对上海某办公建筑空调系统进行分析,研究了带空气全热交换器新风机组的节能潜力,可以为该类建筑空调系统的设计与节能量确定提供参考。     

热回收新风机在住宅建筑中的应用

排风热回收能有效降低建筑物的冷或热负荷,地板送风技术具有换气效率高的优点.介绍了采用新型扁平风管,将排风热回收和地板送风技术结合起来,应用于住宅建筑中的范例.     

空气源热泵全年能耗分析应用软件的开发

介绍了空气源热泵奏年能耗分析应用软件的开发,该软件根据空调冷负菏、室外干球温度、热泵出水温度求解热泵供冷全年能耗;在求热泵共热能耗时,除考虑上述3个参数以外,还将室外空气相对湿度这一重要因素考虑到热泵供热性能中,使热泵供热能耗计算更准确。     

Temperature ranges of the application of air-to-air heat recovery ventilator in supermarkets in winter, China

Energy consumption is an important issue in China. In heating, ventilation and air conditioning (HVAC) systems, more and more commercial buildings use air-to-air heat recovery ventilators as energy saving units for recovering heat from the exhaust air in ventilation systems in current years. In the present paper, critical temperatures of air-to-air heat recovery systems for supermarkets in winter are recommended and discussed for the four cities in different climate zones of China. The analysis shows that the temperature of fresh air in winter can be categorized into three regions, i.e., recovery region, transition region and impermissible recovery region. The results also indicate that the latent heat recovery is not suitable for ventilation energy savings in supermarkets in winter. Meanwhile, the applicability of sensible heat recovery in supermarkets depends on outdoor climate and fresh air flow rate. If a variable rotational speed fan is used to introduce fresh air into the building, heat recovery does always function as planned in winter for all the selected cities except Guangzhou, and most values of the COP are much higher than 2.5. Otherwise, there is the risk of negative impact on building energy savings in all cities except Harbin.