分体式空调办公建筑不同设定温度模式下的人体热适应

以公共建筑设定温度规定(26℃)为界限，按照设定温度的高低分为不同模式。为研究分体式空调办公建筑不同设定温度模式下的人体热适应，本文对郑州市和焦作市的分体式空调办公建筑进行了现场调研，测量了室内外热环境参数和手背皮肤温度，并调查了受试者的热舒适状况。研究发现：长期处于低设定温度模式环境中，会破坏人体对偏热环境的生理适应能力。高设定温度模式下，人们会更积极地通过减少衣着和提高风速的行为来改善热不舒适。由于2种模式拥有类似的热经历和相同的感知控制，因此在相同的标准有效温度范围内，2种模式的热感觉、热可接受度和热舒适并无显著性差异。基于人体热适应分析，寒冷地区分体式空调办公建筑合理提高设定温度可节约34.4%的能源。应继续加强“办公场所夏季制冷温度设置不低于26℃”的政策引导。研究结果可为分体式空调办公建筑的人体热需求和政府节能政策提供理论依据。     

居住建筑空调能耗模拟及夏季室内温度设定

居住建筑空调既应以满足人的舒适和健康为前提,又应以保护环境、节约能源为原则.本文结合厦门气候条件,对居住建筑空调系统在不同室内空气设定温度下的运行情况进行能耗模拟,得到不同设计条件下的空调能耗量.基于这项分析,同时考虑居室人的热舒适感受,得出厦门夏季居住建筑室内空气设定温度值为28.1～28.7℃.PMV-PPD指标分析表明,夏季室内空气温度设定为28.1～28.7℃时,能满足-1≤PMV≤+1,PPD≤27%的热舒适要求.能耗模拟计算显示,与居室设定温度26℃相比,设定温度28.1～28.7℃可使空调节能12.4%～15.9%.     

办公建筑个体舒适装置使用行为研究

通过受试者实验对办公环境中人员使用个体舒适装置的热舒适状态及使用行为规律进行了分析,用条件概率模型对使用行为进行了描述。对上海某办公建筑中的人员位移进行了现场实测,获得了人员移动规律。应用得到的使用行为模型和位移模型对该办公建筑进行了建筑环境模拟,分析了个体舒适装置的节能潜力。结果表明,使用个体舒适装置可以使夏季空调设定温度提高2.0℃,冬季降低2.5℃,使空调供暖供冷能耗降低25%～40%。     

夏季空调混合运行模式建筑室内热环境和人体热舒适研究

我国民用建筑在夏季多采用空调间歇运行模式.本文对焦作市间歇使用空调的办公与住宅建筑的室内热环境与居民热舒适情况进行了实地调研,通过对比分析发现办公建筑的空调使用率和使用强度均高于住宅建筑,且2类建筑空调使用模式有显著差异.尽管办公建筑操作温度显著低于住宅建筑,但2类建筑有着相近的中性温度(28.0℃和27.6℃)和80％可接受温度上限(29.5℃和29.9℃),这主要是因为空调为使用者提供了大量的适应机会,从环境和心理上缓解了人们的热不适,在此基础上提出夏季空调间歇运行模式建筑室内温度动态设计策略.ASHRAE 55热适应模型更适用于评价间歇使用的分体式空调建筑.以上研究对空调混合运行模式建筑的空调控制策略和室内热舒适评价提供了参考.     

办公建筑室内设定参数PMV-PPD分析与空调能耗模拟

办公建筑空调既应以满足人的舒适和健康为前提,又应以保护环境、节约能源为原则。本文基于PMV-PPD评价指标分析,认为厦门夏季办公建筑室内舒适温度设定范围是23.1～28.4℃。通过能耗模拟软件,对厦门夏季大型写字楼空调系统在不同室内设计温度下的运行情况进行模拟,得到不同设计条件下空调能耗量的变化。综合分析表明,厦门夏季大型写字楼空调房间温度值可设定为27～28℃。该设定值与以往室内温度设定值25℃相比较,可在保证人员热舒适的条件下,使大型写字楼的空调能耗减少8.3%～11.9%,对厦门的建筑节能具有重要意义。     

哈尔滨地区办公建筑夜间机械通风能耗及室内热环境分析

采用EnergyPlus软件对哈尔滨地区典型办公建筑在常规空调系统运行模式与夜间机械通风系统运行模式下的室内热环境和能耗进行了模拟。结果表明,在哈尔滨地区,白天室外最高温度高于24℃时都适合进行夜间机械通风,一共约60d,占空调运行期的72.3%;整个夏季空调运行期内,采用夜间机械通风系统该办公建筑节电量指标为1.15kWh/(m2.a),节省运行费用指标为1.02元/(m2.a);在人工制冷阶段,夜间机械通风模式下的室内热环境明显优于常规空调模式,且房间体积与表面积比越小,越有利于提高室内环境的热舒适性;当室内空气设计温度较高时,室内温度下降大,延迟人工制冷开启时间长,但是节能量未必比室内设计温度较低时高。     

西安市办公建筑室内热湿环境与空气品质

选取西安市两幢办公建筑(建筑A采用风机盘管加新风系统,新风未经处理;建筑B采用风机盘管系统加自然通风)作为研究对象,对夏季室内热湿环境(评价指标为室内温度、相对湿度、风速)、过渡季及夏季室内空气品质(采用空气质量综合指数评价法,代表性污染物选取二氧化碳、甲醛、总挥发性有机物)进行实测与评价。两幢办公建筑夏季室内温度、相对湿度、风速均符合设计标准。过渡季二氧化碳、总挥发性有机物均表现出较强的污染程度,夏季污染程度最大的为二氧化碳,甲醛在过渡季、夏季的污染程度最低。夏季室内空气品质优于过渡季,夏季空调环境比过渡季自然通风更有利于室内污染物的扩散,避免污染物含量局部偏高。配置新风系统的空调系统比风机盘管系统加自然通风,更有利于保证良好的室内空气品质。     

关于夏季热湿负荷的分别解决方式

夏季的空调负荷可分为2个部分，1．用于降低室内温度：2．是用于去除室内空气中的水分。 降低室内温度仅需略低于室温（26℃）即可。而除湿就需要低于露点温度，且越低除湿能力就越大。根据制冷原理，温度越低其COP就越小。因此，现有的空调系统为了满足除湿要求将冷冻水的温度定为7℃。即降温和除湿均用7℃的水，这就造成了能源的浪费。     

夏季空调器设定温度对耗电量影响的实测研究

夏季房间空调器的使用能耗在住宅总能耗中占有相当的比例,空调节能是住宅节能工作的重要内容。通过广东省茂名市某卧室房间空调器使用的现场实测,研究了空调设定温度对空调耗电量的影响,结果表明,在湿热地区,空调设定温度对耗电量影响很大,实验日条件下,空调设定温度由26℃降低为25℃时,耗电量上升了47.89%,而空调设定温度由27℃降低为25℃时,耗电量上升了134.35%。实验分析指出,若能改善房间空调器的除湿特性,避免出现因湿度问题而降低室内设定温度的情况,将有效节省房间空调器的使用能耗。     

办公建筑提高夏季空调设定温度对建筑能耗的影响

提高夏季空调设定温度对不同类型办公建筑能耗的影响程度不同。以北京地区办公建筑为研究对象,分别对3种空调设定温度下的建筑能耗进行了模拟。针对大、中、小型办公建筑,分析了影响其节能量的主要因素,并提出了相应的改善措施。     

某化纤厂涤纶长丝装置卷绕间通风系统设计

对某涤纶长丝装置的侧吹风送风、卷绕送风、卷绕回风的设计情况作了简要的介绍。并介绍了设计中应该注意的几个问题。     

中石化电子信息系统机房精密空调设计

中石化电子信息系统机房位于一楼,属于老楼改造,所以在设计精密空调时受格局、层高等诸多限制。本文总结了机房精密空调的设计原理,并结合图纸分析比较了不同设计方式的优缺点。     

Thermal Comfort in the Near-Zone of a Radiator Air Device

Abstract The near-zone of an air inlet device is the most critical part of a room as regards fulfilment of the thermal conform demands. An acceptable solution for residential buildings can be to supply the outdoor air through an air device placed behind a radiator. Such a device provides a mechanical exhaust system that supplies pre-heated outdoor air. Normally radiator air devices are located below a window and a window-sill. To examine the influence of a window-sill placed above an air device, several different positions and breadths of sills were tested. Air velocities and air temperatures were measured at distances within 0.50 m from the device. The measurements show that thermal comfort is strongly dependent on the location of the window-sill in relation to the air device. The degree of turbulence intensity affects the percentage of dissatisfied people due to draught. The velocity measurement system used in this study allows variation of the time constant of the system. When different time constants were used, the measured turbulence intensity varied considerably. Some measurements were carried out with the radiator switched off. In these cases different air velocities were measured, depending on the orientation of the sensors. This seems to be due to the temperature and velocity gradients at the measuring points.     

Removal of viable bioaerosol particles with a low-efficiency HVAC filter enhanced by continuous emission of unipolar air ions

Continuous emission of unipolar ions has been shown to improve the performance of respirators and stationary filters challenged with non-biological particles. In this study, we investigated the ion-induced enhancement effect while challenging a low-efficiency heating, ventilation and air-conditioning (HVAC) filter with viable bacterial cells, bacterial and fungal spores, and viruses. The aerosol concentration was measured in real time. Samples were also collected with a bioaerosol sampler for viable microbial analysis. The removal efficiency of the filter was determined, respectively, with and without an ion emitter. The ionization was found to significantly enhance the filter efficiency in removing viable biological particles from the airflow. For example, when challenged with viable bacteria, the filter efficiency increased as much as four- to fivefold. For viable fungal spores, the ion-induced enhancement improved the efficiency by a factor of approximately 2. When testing with virus-carrying liquid droplets, the original removal efficiency provided by the filter was rather low: 9.09 +/- 4.84%. While the ion emission increased collection about fourfold, the efficiency did not reach 75-100% observed with bacteria and fungi. These findings, together with our previously published results for non-biological particles, demonstrate the feasibility of a new approach for reducing aerosol particles in HVAC systems used for indoor air quality control. PRACTICAL IMPLICATIONS: Recirculated air in HVAC systems used for indoor air quality control in buildings often contains considerable number of viable bioaerosol particles because of limited efficiency of the filters installed in these systems. In the present study, we investigated - using aerosolized bacterial cells, bacterial and fungal spores, and virus-carrying particles - a novel idea of enhancing the performance of a low-efficiency HVAC filter utilizing continuous emission of unipolar ions in the filter vicinity. The findings described in this paper, together with our previously published results for non-biological particles, demonstrate the feasibility of the newly developed approach.     

大型商业中心室内空气品质分析及措施探讨

通过对两家采用空调系统的大型综合性商业中心的空气品质进行监测，取得大量的数据，分析了室内空气污染物浓度的影响因素，并提出了改善室内空气品质的措施。     

空气滤清器与空气预滤器的匹配

工程机械多在高粉尘的环境中工作,工作环境比较恶劣,而粉尘是导致内燃机早期磨损的主要原因,安装空气滤清器是解决这一问题的主要手段.在空气滤清器上加装空气预滤器可以延长滤清器的维护保养时间和使用寿命,降低整机的维护使用成本,通过理论分析和数值计算,合理地匹配空气滤清器和空气预滤器,可使空气滤清器的维护保养时间延长.     

Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners

This study, a randomized controlled trial, evaluated the effectiveness of free-standing air filters and window air conditioners (ACs) in 126 low-income households of children with asthma. Households were randomized into a control group, a group receiving a free-standing HEPA filter placed in the child's sleeping area, and a group receiving the filter and a window-mounted AC. Indoor air quality (IAQ) was monitored for week-long periods over three to four seasons. High concentrations of particulate matter (PM) and carbon dioxide were frequently seen. When IAQ was monitored, filters reduced PM levels in the child's bedroom by an average of 50%. Filter use varied greatly among households and declined over time, for example, during weeks when pollutants were monitored, filter use was initially high, averaging 84±27%, but dropped to 63±33% in subsequent seasons. In months when households were not visited, use averaged only 34±30%. Filter effectiveness did not vary in homes with central or room ACs. The study shows that measurements over multiple seasons are needed to characterize air quality and filter performance. The effectiveness of interventions using free-standing air filters depends on occupant behavior, and strategies to ensure filter use should be an integral part of interventions. PRACTICAL IMPLICATIONS: Environmental tobacco smoke (ETS) increased particulate matter (PM) levels by about 14 μg/m3 and was often detected using ETS-specific tracers despite restrictions on smoking in the house as reported on questionnaires administered to caregivers. PM concentrations depended on season, filter usage, relative humidity, air exchange ratios, number of children, outdoor PM levels, sweeping/dusting, and presence of a central air conditioner (AC). Free-standing air filters can be an effective intervention that provides substantial reductions in PM concentrations if the filters are used. However, filter use was variable across the study population and declined over the study duration, and thus strategies are needed to encourage and maintain use of filters. The variability in filter use suggests that exposure misclassification is a potential problem in intervention studies using filters. The installation of a room AC in the bedroom, intended to limit air exchange ratios, along with an air filter, did not lower PM levels more than the filter alone.     

Three-dimensional numerical simulation of a hybrid fresh air and recirculated air diffuser for decoupled ventilation strategy

In conventional mixing ventilation air conditioning system, fresh air which has been polluted by recirculated air is supplied to occupied zone. Therefore, more fresh air which results in energy penalty needs to be supplied in order to keep good indoor air quality (IAQ) and thermal comfort. Some alternatives such as personalized ventilation air conditioning system can address this problem effectively by supplying fresh air directly into occupied zone. However, room layouts and visual effects will be influenced deeply because of extended air ducts. A new approach supplying fresh air directly by utilizing high velocity circular air jet without mixing with recirculated air is introduced. Objective measurements and computational fluid dynamics (CFD) tool are used to evaluate corresponding indoor parameters to verify that it can both supply fresh air into occupied zone effectively and avoid draught rating.     

Hygienic Aspects of Ground-Coupled Air Systems

Abstract Numerous ground-coupled air systems have been constructed in combination with heat recovery units in mechanically ventilated buildings in Switzerland. The objective of this study was to investigate the microbial content within these ventilation systems and to monitor the quality of the air supply. The concentrations and the types of microorganisms in the outdoor air, in the air of the pipes and in the supply air of twelve ground-coupled air systems were determined. In addition, three buildings were examined four times a year to cover seasonal changes. In general, the concentrations of fungal spores and bacteria in the air at the end of the underground pipes were lower than in the outdoor air, but great differences were observed between ventilation systems of large buildings and one-family houses. Occasionally, an increase in the concentration of Penicillium, Aspergillus or Actinomycetes was noted within a piping system. The concentrations in the supply air behind the filters were always low. Based on these investigations, the operation of ground-coupled air systems can be recommended as long as regular controls are undertaken and cleaning facilities are available.     

Experimental investigation of a novel desiccant cooling system

Desiccant based air conditioning systems are a suitable way to improve indoor air quality due to its superior humidity control. In this study, a novel desiccant based air conditioning system is designed and tested experimentally to improve the indoor air quality and reduce energy consumption. In the system studied, a heat exchanger, which is not used in this type of systems, for pre-heating the regeneration air with exhaust air is used. This paper reports results of initial operation and operational procedures. The performance of the system and its components is discussed.