新建居住建筑供暖效果影响因素的计算分析

以北京市两栋装有分户热计量装置的新建住宅楼为研究对象,对楼内的113个住户进行冬季供暖耗热量、热水流量以及供回水温度等相关数据的定期采集,并在供暖季对其中9个住户的房间进行室温的连续测试。统计结果表明,住户的供暖耗热量高于北京现行节能标准的要求,但围护结构并不是影响住户供暖能耗大小的主要原因。通过对典型住户室内热环境的模拟计算及分析对比发现,房间通风状况、邻室室温状况、房间遮阳状况以及客厅与阳台门的开关状况等人的行为因素对住户的供暖效果产生不可忽视的重要影响。     

居住建筑围护结构的节能问题

从适宜居住的角度讲,我国绝大部分地区的居住建筑都要采取一定的技术措施来保证冬夏两季的室内热舒适环境。冬夏两季室内维持的温度与室外的温度有很大的差别,这个温差导致能量以热的形式流出或流入室内,采暖,空调设备消耗的能量主要就是用来补充这个能量损失的。在相同的室内外温差条件下,建筑围护结构保温隔热性能的好坏,直接影响到流出或流入室内的热量的多少。建筑围护结构保温隔热性能好,流出或流入室内的热量就少,采暖,空调设备消耗的能量也就少;反之,建筑围护结构保温隔热性能差,流现或流入室内的热量就多,采暖,空调设备消耗的能量也就多。我国现行的居住建筑节能设计标准对建筑围护结构保温隔热性能提出了明确的要求,按照节能设计标准的要求去设计,新建的居住建筑就能比具有传统围护结构的同类建筑节约25％－35％的采暖,空调能耗,而且节能的潜力还十分巨大。     

Energy, comfort and indoor air quality in nursery and elementary school buildings in the cold climatic zone of Greece

Schools are the most suitable type of building for the application of energy efficiency and good indoor air quality measures. This is justified by the fact that such measures can promote sustainability to the future citizens, and even more, ensure a comfortable and healthy environment for educational purposes. Unfortunately, in practice school buildings face the same, or even more intense, energy performance and indoor air quality problems as any other building. The purpose of this study is to investigate the energy efficiency, thermal environment and indoor air quality in public nursery and elementary school buildings in the city of Kozani, located at the cold climatic zone of Greece. The survey, conducted both by in-field measurements and by questionnaires, reveals the main parameters affecting the overall performance of the investigated buildings. The problematic building envelope, the improper control of heating and lighting systems, the absence of proper legislative measures and, above all, the lack of interest concerning the efficiency of such buildings are the main factors in the reported efficiency.     

Practical experiences with IR-controlled supply terminals in dwellings and offices

Ventilation is necessary to provide good indoor air quality to occupants in buildings but can be a major energy consumer. Results from two experimental studies carried in several dwellings and in office buildings show that the use of presence detection (infrared sensor) for controlling ventilation has a potential for substantial reductions in the heating energy consumption. A simulation study of the impact of infrared spectroscopy (IR) controlled ventilation on the yearly heating energy consumption was performed and it showed that reductions from 27% to 47% can be obtained in well insulated office buildings.     

Energy performance and indoor environmental quality in Hellenic schools

School buildings constitute a major part of the non-residential building stock, though due to their operational characteristics, they represent a low percentage of the overall energy balance of the building sector. Although health and productivity of pupils and teachers is strongly affected by the indoor environmental quality of their school, poor indoor air quality has been reported in published literature, even so for recently constructed school buildings. The same applies for the energy consumption, with large amounts of energy being wasted because no energy saving measures are applied for the operation of schools. This paper presents the outcome of a study on the energy performance of Hellenic school buildings. The general features of the contemporary building stock are presented along with the results from an energy survey in 135 Hellenic schools. The derived energy consumption benchmarks are compared with published literature. Finally, the energy performance and indoor environmental quality of a representative sample of schools in metropolitan Athens are assessed in a holistic approach to the “energy efficiency – thermal comfort – indoor air quality” dilemma. The IEQ assessment was based on an objective evaluation by monitoring crucial indoor conditions and a subjective occupant evaluation using standardized questionnaires. The potential of several energy conservation measures is evaluated in terms of energy savings and reduction of greenhouse gas emissions along with the related payback periods.     

Flow patterns and thermal comfort in a room with panel,floor and wall heating

Thermal comfort aspects in a room vary with different space heating methods. The main focus in this study was how different heating systems and their position affect the indoor climate in an exhaust-ventilated office under Swedish winter conditions. The heat emitters used were a high and a medium–high temperature radiator, a floor heating system and large wall heating surfaces at low temperature. Computational fluid dynamics (CFD) simulations were used to investigate possible cold draught problems, differences in vertical temperature gradients, air speed levels and energy consumption. Two office rooms with different ventilation systems and heating needs were evaluated. Both systems had high air exchange rates and cold infiltration air.     

住宅建筑采暖空调能耗模拟方法的研究

住宅建筑的采暖空调能耗受室内居住人员行为方式的影响,在调查研究基础上,确定了两种反映室内居住人员行为方式的计算模式。在两种不同计算模式下,利用建筑热环境模拟工具DeST对上海地区同一住宅建筑能耗进行模拟,并将模拟结果与调研结果进行比较,分析计算模式对上海地区住宅建筑采暖空调能耗大小的影响,从而获得能正确反映上海地区住宅建筑采暖空调能耗大小的模拟计算方法。此方法可用于上海地区住宅建筑采暖空调的能耗分析与评价,并正确指导住宅建筑的节能设计。     

夏热冬冷地区冬季供暖方式的选择

对夏热冬冷地区非供暖居住建筑冬季室内环境参数进行了实测，结果表明这类建筑冬季室内约80％的时间达不到人体健康要求的最低温度，明显具有不同于集中供暖地区建筑的室内热环境特征，且房间气密性和朝向对室内温度影响较小。分析了不同气密性房间供暖能耗的构成和不同供暖方式的节能效果，指出房间气密性是夏热冬冷地区选择供暖方式和设备的主要依据。     

分体空调的室内环境与新风

选择典型的装有分体空调的居室和办公室，对新风不同引入方式下冬夏室内的环境参数作了测试，比较并分析了新风引入方式对室内热环境、空气品质、噪声、空调能耗及运行经济性的影响，认为使用具有显热交换功能的新风换气机可获得显著的环境效益和经济效益。     

Categories of indoor environmental quality and building energy demand for heating and cooling

Maintaining suitable indoor climate conditions is a need for the occupants’ well being, while requiring very strictly thermal comfort conditions and very high levels of indoor air quality in buildings represents also a high expense of energy, with its consequence in terms of environmental impact and cost. In fact, it is well known that the indoor environmental quality (IEQ), considering both thermal and indoor air quality aspects, has a primary impact not only on the perceived human comfort, but also on the building energy consumption. This issue is clearly expressed by the European Energy Performance of Buildings Directive 2002/92/EC, together with the most recent 2010/31/EU, which underlines that the expression of a judgment about the energy consumption of a building should be always joint with the corresponding indoor environmental quality level required by occupants. To this aim, the concept of indoor environment categories has been introduced in the EN 15251 standard. These categories range from I to III, where category I refers to the highest level of indoor climate requirement. In the challenge of reducing the environmental impact for air conditioning in buildings, it is essential that IEQ requirements are relaxed in order to widen the variations of the temperature ranges and ventilation air flow rates. In this paper, by means of building energy simulation, the heating and cooling energy demand are calculated for a mechanically controlled office building where different indoor environmental quality levels are required, ranging from category I to category III of EN 15251. The building is located in different European cities (Moscow, Torino and Athens), characterized by significantly different wheatear conditions. The mutual relation between heating and cooling energy demand and the required levels of IEQ is highlighted. The simulations are performed on a typical office room which is adopted as a reference in validation tests of the European Standard EN 15265 to validate calculation procedures of energy use for space heating and cooling.     

Residential air-to-air heat exchangers: Performance energy savings,and economics

Residential energy consumption can be decreased if air infiltration is reduced by constructing houses more tightly. In some cases, however, reduced air infiltration can lead to problems with indoor air quality (e.g., excess humidity and high levels of indoor-generated air contaminants). One solution to this problem is to install a residential air-to-air heat exchanger. The heat exchanger provides a controlled supply of ventilation which counteracts the adverse effects of reduced infiltration. In addition, the heat exchanger recovers much of the energy that would normally be lost when ventilation occurs by air infiltration. Thus, by employing heat exchangers in low-infiltration houses, it is possible to save energy without sacrificing indoor air quality.This paper discusses the performance of residential heat exchangers and summarizes results from tests of several models. It also compares the energy consumed, during the heating season, in low-infiltration houses with heat exchangers, with the energy consumed in typical houses in four cities throughout the United States. For each city, a cost-benefit analysis is performed from the point of view of a home-owner. Houses with natural gas, oil, and electrical heating systems are considered. Our analysis indicates that the energy required to heat ventilation air in homes employing heat exchangers is 5.3 – 18.0 GJ less than the energy required to heat ventilation air in typical homes. In homes with heat exchangers, the heat exchanger's fan system required 2.2 – 3.6 GJ of electrical energy during the heating season. The net present benefit for homes employing heat exchangers, when compared with typical homes, ranged from —$1350 to +$2400 and discounted payback periods ranged from five to over 30 years. The cost-effectiveness of employing heat exchangers was found to be highly affected by climate, type of heating fuel, heat exchanger performance, and ventilation rate.     

带热回收的新风空调系统在医院建筑中的应用分析

针对一个独立新风、集中排风并带全热交换器能量回收的医院输液室空调系统,实验测试了空调系统的能耗,计算了全年节能潜力,并通过测量室内CO2浓度,研究了通风对室内空气质量的改善程度。结果表明,该空调系统在改善室内空气质量的同时可以节约能量,是医院建筑的理想空调系统。     

Ventilation,indoor environment quality and climate—comparison of European and Singapore office buildings

Indoor environment quality audits were performed in six European countries and in Singapore using the same methodology. Five to eight office buildings were audited in each country. The audits included airflow rate measurements, energy audit, indoor air quality (VOC₁ CO₂, dust concentrations), and questionnaires to occupants. Questions to occupants addressed their health, their comfort and well-being, as well as their perception of their environment. This paper compares the results obtained from these audits, with particular attention to the effects of ventilation or air conditioning systems and climate.

The number of building related symptoms is, on the average, significantly smaller in the buildings audited in Singapore than in Europe. One of the reasons may be the non-smoking policy common in Singapore. It is also once more observed that buildings are often over-warmed in cold climates and overcooled in warm climates. Surprising, but not new, is that there are no correlations between specific air flow rates and perceived air quality or health, as long as airflow rates are within accepted standards.     

Control of heating systems in residential buildings: Current practice

Heating is the most important energy consumer for households in Belgium. The primary energy consumption of a heating system is determined by the net energy demand of the building, but also by the efficiency of the equipment and the way it is used by the inhabitants.

To estimate the potential primary energy savings, today's situation should be analysed first. Therefore, the results of two surveys are combined to sketch current practice in Belgium. The most common systems in Western Europe, i.e. gas boilers combined with radiators, are then simulated to test their performance in dwellings with varied insulation quality. Typical internal heat gains and set temperature profiles are included, but the influence of the inhabitant behaviour on the heating efficiency is not studied as such.

The results show that current practice does lead to important energy losses, resulting in overall efficiencies as low as 30%, but improvements are possible by using intelligent controllers. However, correct boiler sizing and a sound combination of boiler and heat emitter control are still required to ensure high heating system efficiencies, especially for better insulated buildings with a high heat balance ratio.     

蓄热型空气式太阳能集热-空气源热泵复合供暖系统在寒冷地区的应用研究

设计了一种蓄热型空气式太阳能集热-空气源热泵复合供暖系统.该系统具有太阳能供热、太阳能辅助热泵供热和热泵供热3种运行模式,可根据环境工况及供暖负荷的变化自动切换运行模式,保证室内供暖的稳定性.在通辽市的实验研究结果表明:在整个供暖季内,该系统可持续提供42.6 ℃的热水,维持室内温度在21.3?24.1 ℃之间;平均C...     

Improving energy performance of school buildings while ensuring indoor air quality ventilation

Energy conscious design of school buildings, as well as deemed-to-satisfy provisions in a Performance Based Energy Code, should address the problem known as the energy efficiency—thermal comfort—indoor air quality dilemma (EE-TC-IAQ Dilemma). In warm and moderate climates, the large internal heat sources usually found in school buildings prevent achieving thermal comfort without active cooling in summer, but are not sufficient to eliminate the need for heating in winter. Commonly used air-conditioners do not improve air quality, while natural ventilation induces uncontrolled energy losses. In this study, a step by step process was used for the development of deemed-to-satisfy design solutions, which cope with the EE-TC-IAQ Dilemma, for a performance based code. A distinction is made between improving building design variables and improving ventilation schemes. Results indicate that implementation of improved ventilation schemes in an otherwise well designed energy-conscious building result in savings of 28–30% and 17–18% for northern and southern classroom orientations, respectively.     

西北村镇单体建筑室内空气质量研究

基于西北村镇传统单体建筑能源利用率低、室内空气质量差的现状,将传统建筑的供能系统改为冬季主要由太阳能热水系统为室内供暖且为住户提供生活热水,并对建筑室内空气质量进行试验测试,测试结果得到:室内SO_2、NO_2、CO含量的1 h平均值,TVOC含量的8 h平均值,CO_2、PM_(10)含量的日平均值、室内风速和室内空气相对湿度在试验周期内都符合GB/T 18883—2002《室内空气质量标准》的相关规定,室内温度平均值在太阳能热水系统供暖期间符合GB/T 50824—2013《农村居住建筑节能设计标准》的相关规定;经综合指数对室内空气质量进行评价,得出太阳能热水系统供能的西北村镇单体建筑空气质量级别属于Ⅱ级,空气质量评价结果为未污染。     

对热舒适、空气感觉质量及能耗的模拟研究

室内空调设计温度和新风量对热舒适，室内空气质量及能耗量有重要影响，然而对它们之间相互关系进行研究的文献却较少。通过计算机模拟空调系统在7种室内设计温度和7种新风量条件下的运行情况，得到不同的设计条件组合对热舒适、人体感觉空气质量及建筑能耗量的影响。基于这项分析，提出了此办公建筑合理的室内设计温度和新风量取值。     

Control of indoor CO2 concentration based on a process model

Air-tight buildings need to have ventilation systems, although the use of these systems results in heavy energy consumption within the building sector. For this reason they have to be adequately regulated in order to achieve good indoor air quality and lower operation costs. The main challenge is to optimize regulation in office buildings, theaters, museums, and schools, where there are large fluctuations and heavy operating costs. Each further optimization leads directly to a better indoor climate and a reduction in energy consumption. In the case of ventilation systems, PI or PID regulators are usually used. In the described research an internal model control (IMC) system was designed with an internal loop, which constantly checks the momentary CO₂ concentration, and makes the necessary adjustments to the air flow. The results showed a significant improvement in the CO₂ level when using an IMC controller, in comparison with PI controller. The desired indoor air quality is achieved more than 80% of the time, with lower operating costs.     

确定长江流域供暖空调能耗指标的边界条件

讨论了影响长江流域住宅供暖空调能耗水平的诸因素,包括热环境质量、室内空气品质和新风量、供暖空调系统和比和性能系数、供暖期空调期除湿期天数及建筑热工特性等,给出了这些因素的建议值。