上海市某办公建筑PM_(2.5)浓度分布及影响因素的实测研究

通过对上海市某办公建筑在不同时段和条件下PM2.5等颗粒物浓度的现场测试,得到室内PM2.5浓度分布及变化特性,并分析了影响PM2.5浓度变化的室外颗粒物浓度、门窗开启情况、测试时段、室内人员、吸烟、空调系统、地毯扬尘等因素,探讨了PM2.5与其他粒径颗粒物浓度变化的相关性。实测发现办公楼室内PM2.5浓度在不同时期的变化较大,为了室内工作人员的身体健康,建议在颗粒物污染较严重时期,尽量少开门窗,加强新风过滤处理,在室内发尘较严重的区域,建议同时使用局部净化设备。     

严寒地区被动房室内环境与供暖能耗后评估

对严寒地区某被动房示范项目的室内环境和供暖能耗进行了后评估,并与位于同一小区的普通住宅进行了对比分析。结果表明：被动房高性能的围护结构可有效提高室内操作温度,且由于设置了机械通风系统,可有效稀释室内CO₂浓度;被动房供暖季室内PM2.5浓度超标,新风系统对细颗粒物的过滤效率不满足要求;被动房供暖实际运行能耗高于超低能耗建筑年供暖耗热量指标,偏差达到33.6%。     

上海市五类公共建筑室内PM2.5浓度的实测研究

本文通过对上海市五类公共建筑在不同时段和条件下PM2.5等颗粒物浓度的现场测试,得到PM2.5浓度分布及变化特性,对各类公建总体PM2.5浓度水平和来源进行了对比分析,并研究了PM2.5与其他粒径颗粒物浓度变化的相关性。此外,本文还探讨了影响五类公建室内PM2.5浓度变化的不同因素。实测发现公共建筑室内PM2.5浓度在不同时期的变化较大,为保证室内工作人员的身体健康,建议在颗粒物污染较严重时期,尽量少开门窗,加强新风过滤处理,在室内发尘较严重的区域,建议同时使用局部净化设备或措施。     

住宅室内PM2.5净化状况的实测研究

为认识住宅室内PM2.5实际的通风净化状况,对北京地区15户住宅客厅和卧室的室内PM2.5浓度、空气净化器和机械新风系统的运行功率及外窗开关状态进行了连续测试记录。基于不同室外PM2.5污染等级下室内PM2.5质量浓度低于35μg/m~3的相对时长,提出了室内PM2.5净化时间达标率的概念,由此分析了室外PM2.5污染等级、房间通风净化方式等对室内PM2.5净化时间达标率的影响。结果表明:现有以开窗率和净化开启率描述的通风净化策略并不理想;对于室外PM2.5污染等级为轻度至重度的情况,通过优化通风净化策略可改善室内PM2.5环境。     

住宅新风净化与室内空气品质

通过对南京和上海的各两台新风机组处理段的颗粒分布和PM10,PM2.5的浓度测试,分析了新风机组过滤器的性能以及过滤器的布置位置对新风品质的影响,并根据各处理段颗粒物浓度变化情况研究了影响室内空气品质的因素,以不断完善与优化新风空调过滤系统的性能。     

某中学教室PM2.5污染防护技术方案分析及工程效果验证

对上海市某中学教室进行了实测,结果表明目前该教室缺乏有效的机械通风手段,导致通风不足、CO_2浓度易超标、不能有效防护室外颗粒物污染等问题。通过方案比选,提出了新风净化方案,并实施了工程改造。改造后的实测结果显示,新风净化技术可有效降低该教室室内PM2.5和CO_2浓度水平,提高室内空气质量。     

室内外PM2.5质量浓度影响因素与室内控制措施

选取哈尔滨(严寒地区)、天津(寒冷地区)、武汉(夏热冬冷地区)、广州(夏热冬暖地区)和昆明(温和地区)作为我国5个气候区域的代表性城市,以2014年1月至2015年12月室外细颗粒物(PM2.5)质量浓度数据作为样本,对室外细颗粒物质量浓度的影响因素进行研究。对于广州、昆明,由于气候条件、能源使用强度低等原因,室外细颗粒物质量浓度明显小于其他3座城市。虽然武汉不属于集中供热区域,但冬季居民分散供暖造成能源使用强度较高,室外细颗粒物年平均质量浓度仍较高。即使门窗关闭,室外PM2.5质量浓度仍对室内PM2.5质量浓度有显著影响。空气净化设备(独立式净化器、集中式净化系统)可有效降低室内细颗粒物质量浓度。独立式净化器占地面积小,使用灵活,净化效果较好,但不具备新风处理功能,为降低室内空气二氧化碳体积分数,仍需开窗通风。当室外污染物浓度高时,开窗通风不仅易将室外污染物引入室内,而且在冬季将室外冷空气引入室内使人有吹风感,且会增大热负荷。集中式净化系统兼具室内空气净化功能与室外新风处理功能,在保持室内细颗粒物质量浓度较低水平的同时,还能满足二氧化碳体积分数要求。     

动车组车厢内空气颗粒物浓度实测与分析

通过对颗粒物各粒径段浓度数据处理以及耦合通风空调系统,得到了新风对颗粒物计数浓度的贡献率和客室内贡献率公式.进而分析了动车组车厢内的颗粒物粒径分布特征以及新风、客室内对颗粒物计数浓度的贡献情况.结果表明客室内颗粒物主要由PM1.0组成;颗粒物粒径越小,新风贡献率越大,随着颗粒物粒径的加大,新风贡献率逐渐减小,客室内贡献率逐渐增大.该研究结果对解决动车组车厢中可吸入颗粒物浓度控制问题、提高车厢环境空气质量具有指导作用和现实意义.     

住宅新风系统PM2.5控制效果分析

针对影响住宅室内PM2.5的室外源,分析住宅机械通风系统影响室内PM2.5浓度的风量、过滤效率和室内气流组织等主要因素,针对主要影响因素,提出适用于住宅的室内PM2.5控制技术,有PM2.5过滤功能的户式新风系统,进而提出其主要指标要求(换气次数、过滤效率、室内PM2.5控制指标等)、系统形式、送/回风口设置原则等技术要求。针对住宅PM2.5控制系统,建立数学模型,确定计算输入条件,进行理论计算,分析室内PM2.5控制效果。根据理论计算结果可知,当围护结构气密性较好时,采用有PM2.5过滤功能的户式新风系统可有效控制室内PM2.5浓度。     

供暖季颗粒物浓度的时空变化规律及其影响因素

为了解2020年哈尔滨市冬季颗粒物浓度的时空变化规律,分析室外PM10和PM2.5浓度的影响因素。文中采用相关性分析法探讨气象因素对PM2.5和PM10污染物的影响。得出冬季室外颗粒物的浓度相对较高,并且不同地点的颗粒物浓度相差较大,绿地PM2.5、PM10浓度最低,PM2.5、PM10受室外气象因素的影响,与温度及太阳辐射呈负相关。经研究发现,室外颗粒物浓度在不同地点相差很大,并且温度与相对湿度对其影响较大,风速与其相关性较低。     

Numerical investigation on the ingress of particulate matter from ambient air into the inlet of a building air handling unit

The transportation of ambient particulate matter (PM) from outdoor air into the inlet of a mechanical building ventilation system is poorly understood. No studies have examined the effect commonly used commercial air handling unit (AHU) inlet designs have upon the migration of PM from the ambient environment into the building ventilation system, and implications of this on energy consumption and indoor air quality (IAQ). Through the numerical analysis of commercial AHU inlets, the differences in concentration of PM in ambient air and that within AHUs were determined, more commonly referred to as Aspiration Efficiency (AE %). A 20–50% difference in particle concentrations between ambient air and the in-AHU concentration was observed between forward and rear-facing AHUs relative to ambient wind direction and speed, and at the maximum ventilation flow rate. Furthermore, a decrease in the ventilation flow rates resulted in a significant reduction in PM concentrations entering the rear-facing AHU. Increasing the Stoke number led to lower AE as a continuous decrease was observed for both rear-facing inlets. The findings of this paper show that AHU inlet design has significant implications on IAQ and building energy consumption, and scope exists to design these inlets to impact both aspects positively.     

Use of Simulink to evaluate the air-quality and energy performance of HRV-equipped residences in Fairbanks, Alaska

Mechanical ventilation systems in residences usually serve a single purpose, providing only a relatively small benefit compared to the capital cost. Polluted areas use mechanical ventilation to filter incoming air, cold regions use it to be able to recover the heat from the stale air going out. However, both issues – energy and air-quality – can be beneficially addressed together using one ventilation system in cold climate regions with air pollution problems, such as Fairbanks, Alaska. This paper presents a dynamic model for evaluating indoor PM_2.5 levels and energy consumption associated with ventilation. The model was verified by comparing the model-predicted real-time indoor PM_2.5 level with the actual level measured in a Fairbanks home and a good agreement (r = 0.95) was found. Then, the model was used to study three ventilation scenarios of a typical home in Fairbanks—natural ventilation, using an HRV, and using an HRV with an additional particulate filter. The external cost associated with breathing the indoor PM_2.5 was also evaluated. The scenario with an HRV and an additional filter was shown to have about $380 lower annual energy cost than the scenario with natural ventilation and the saving in the PM_2.5 associated external cost was about $690 annually. The savings were shown to exceed the operational costs of the ventilation system.     

道路隧道旁通式ESP空气净化系统及技术

道路隧道旁通式ESP空气净化系统通过在隧道内设置旁路通风系统,利用ESP的高压静电吸附功能,有效去除隧道污染空气中的PM2.5、PM10等颗粒物。本文阐述了ESP空气净化工作原理、ESP系统空气净化技术以及系统结构集成,并将ESP系统与道路隧道常规通风模式进行投资运营技术经济比较,研究ESP系统与消防排烟系统的联合工作方式,以及旁道式ESP空气净化系统对道路隧道实现节能运营、绿色运营和环保运营的可行性和应用前景。     

A review of traditional and advanced technologies for the removal of particulate matter in subway systems

The pollution status of particulate matter (PM) in a subway system and technological trends in their reduction were discussed in this study. The levels of PM_2.5 and PM₁₀ are generally found to be higher in the underground platforms and tunnels than those in the outdoor air. It has also been reported that the composition of fine dust in the subway consists of various substances including heavy metals (like Fe), carbonaceous matter, and solvent extractable organic matter (SEOM). It was confirmed that subway dust was created mainly by wearing on wheels, rails, and brakes. In addition, the concentration of PM in such environment was influenced not only by internal factors (eg, operating conditions of trains and ventilation systems, number of passengers, and the structure of subway stations) but also by outside factors (eg, ambient air concentration). Up to now, various techniques (ventilation fans, platform screen doors (PSDs), magnetic filters, small jet fans, artificial intelligent ventilation systems, hybrid filters, etc) have been studied to reduce PM in underground subway systems. In this study, we reviewed the air quality of major subway stations with the focus on PM and relevant technologies for its reduction.     

Characterization of emissions from burning incense

The primary objective of this study was to improve the characterization of particulate matter emissions from burning incense. Emissions of particulate matter were measured for 23 different types of incense using a cyclone/filter method. Emission rates for PM2.5 (particulate matter less than 2.5 microm in aerodynamic diameter) ranged from 7 to 202 mg/h, and PM2.5 emission factors ranged from 5 to 56 mg/g of incense burned. Emission rates were also determined using an electrical low pressure impactor (ELPI) and a small electrostatic precipitator (ESP), and emission rates were compared to those determined using the cyclone/filter method. Emission rates determined by the ELPI method were consistently lower than those determined by the cyclone/filter method, and a linear regression correlation was found between emission rates determined by the two methods. Emission rates determined by the ESP method were consistently higher than those determined by the cyclone/filter method, indicating that the ESP may be a more effective method for measuring semivolatile particle emissions. A linear regression correlation was also found between emission rates determined by the ESP and cyclone/filter methods. Particle size distributions were measured with the ELPI, and distributions were found to be similar for most types of incense that were tested. Size distributions by mass typically ranged from approximately 0.06 to 2.5 microm in aerodynamic diameter, with peak values between 0.26 and 0.65 microm. Results indicated that burning incense emits fine particulate matter in large quantities compared to other indoor sources. An indoor air quality model showed that indoor concentrations of PM25 can far exceed the outdoor concentrations specified by the US EPA's National Ambient Air Quality Standards (NAAQS), so incense smoke can pose a health risk to people due to inhalation exposure of particulate matter. Emissions of carbon monoxide (CO), nitric oxide (NO), and sulfur dioxide (SO2) were also measured for seven types of incense. Emission rates of the gaseous pollutants were sufficient to cause indoor concentrations, estimated using the indoor air quality model, to exceed the outdoor concentrations specified by the NAAQS under certain conditions. However, the incense samples that were tested would fill a room with thick smoke under these conditions.     

Estimated effect of ventilation and filtration on chronic health risks in U.S. offices,schools, and retail stores

We assessed the chronic health risks from inhalation exposure to volatile organic compounds (VOCs) and particulate matter (PM2.5) in U.S. offices, schools, grocery, and other retail stores and evaluated how chronic health risks were affected by changes in ventilation rates and air filtration efficiency. Representative concentrations of VOCs and PM2.5 were obtained from available data. Using a mass balance model, changes in exposure to VOCs and PM2.5 were predicted if ventilation rate were to increase or decrease by a factor of two, and if higher efficiency air filters were used. Indoor concentrations were compared to health guidelines to estimate percentage exceedances. The estimated chronic health risks associated with VOC and PM2.5 exposures in these buildings were low relative to the risks from exposures in homes. Chronic health risks were driven primarily by exposures to PM2.5 that were evaluated using disease incidence of mortality, chronic bronchitis, and non‐fatal stroke. The leading cancer risk factor was exposure to formaldehyde. Using disability‐adjusted life years (DALYs) to account for both cancer and non‐cancer effects, results suggest that increasing ventilation alone is ineffective at reducing chronic health burdens. Other strategies, such as pollutant source control and the use of particle filtration, should also be considered.     

Comparison of airflow and particulate matter transport in multi-room buildings for different natural ventilation patterns

This study numerically investigates airflow characteristics and particulate matter (PM) transport in multi-room buildings for different natural ventilation patterns with the same air change rate. Four typical natural ventilation patterns (full-open, pass-through, right short-circuit and left short-circuit), representing the ratios of the outlet-to-inlet opening size ranging from 1.67 to 0.17, are considered to study multi-room airflow characteristics. A measured indoor PM₁₀ profile in Taipei Metropolis is input into the above four ventilation patterns as the initial condition of the PM size distribution. The time variation of indoor PM₁₀/PM_2.5/PM₁ concentrations in each room for various ventilation patterns is next investigated. The effect of ventilation pattern on particle removal mechanism is emphasized. The results show that although the air change rate of the building is the same, airflow characteristics and PM transport behaviors are quite different for various ventilation patterns. The removal efficiencies of PM₁₀ for the four ventilation patterns are all found to be much better than those of PM_2.5 and PM₁. Particle escape is the major mechanism to remove PM for rooms with double-sided ventilation, whereas particle deposition is important for single-sided ventilation rooms.     

Isoconcentration mapping of particulate matter in Hamedan intercity bus stations

To accomplish this study, the total concentration of suspended particles, PM₁₀ and PM_2.5, was mapped at intercity bus stations in the central square of Hamedan. To measure the particulate matter (PM), portable air sampling systems that collect integrated filter samples were used. The PM concentration was collected at various time intervals and measured gravimetrically. The results were then analysed using the ArcView GIS 3.3 software to map the particulate dispersion patterns. The mean concentrations of the total suspended particles (TSP), PM₁₀ and PM_2.5 were 1220.94 ± 1418.5, 524.7 ± 217.5 and 386 ± 193.6 μg/m³, which were 16, 7.72 and 4.7 times greater than the World Health Organization (WHO) air quality standard, respectively. The PM concentration was not correlated with wind velocity or air temperature, but was correlated with humidity (P = 0.01). Overall, the results of this pilot study indicate that people at bus stations are exposed to respirable particulate matter (RPM) at levels high enough to pose a serious health risk.     

The impact of particle filtration on indoor air quality in a classroom near a highway

A pilot study was performed to investigate whether the application of a new mechanical ventilation system with a fine F8 (MERV14) filter could improve indoor air quality in a high school near the Amsterdam ring road. PM10, PM2.5, and black carbon (BC) concentrations were measured continuously inside an occupied intervention classroom and outside the school during three sampling periods in the winter of 2013/2014. Initially, 3 weeks of baseline measurements were performed, with the existing ventilation system and normal ventilation habits. Next, an intervention study was performed. A new ventilation system was installed in the classroom, and measurements were performed during 8 school weeks, in alternating 2‐week periods with and without the filter in the ventilation system under otherwise identical ventilation conditions. Indoor/outdoor ratios measured during the weeks with filter were compared with those measured without filter to evaluate the ability of the F8 filter to improve indoor air quality. During teaching hours, the filter reduced BC exposure by, on average, 36%. For PM10 and PM2.5, a reduction of 34% and 30% was found, respectively. This implies that application of a fine filter can reduce the exposure of schoolchildren to traffic exhaust at hot spot locations by about one‐third.     

Particle size distribution and composition in a mechanically ventilated school building during air pollution episodes

Particle count-based size distribution and PM(2.5) mass were monitored inside and outside an elementary school in Salt Lake City (UT, USA) during the winter atmospheric inversion season. The site is influenced by urban traffic and the airshed is subject to periods of high PM(2.5) concentration that is mainly submicron ammonium and nitrate. The school building has mechanical ventilation with filtration and variable-volume makeup air. Comparison of the indoor and outdoor particle size distribution on the five cleanest and five most polluted school days during the study showed that the ambient submicron particulate matter (PM) penetrated the building, but indoor concentrations were about one-eighth of outdoor levels. The indoor:outdoor PM(2.5) mass ratio averaged 0.12 and particle number ratio for sizes smaller than 1 microm averaged 0.13. The indoor submicron particle count and indoor PM(2.5) mass increased slightly during pollution episodes but remained well below outdoor levels. When the building was occupied the indoor coarse particle count was much higher than ambient levels. These results contribute to understanding the relationship between ambient monitoring station data and the actual human exposure inside institutional buildings. The study confirms that staying inside a mechanically ventilated building reduces exposure to outdoor submicron particles. PRACTICAL IMPLICATIONS: This study supports the premise that remaining inside buildings during particulate matter (PM) pollution episodes reduces exposure to submicron PM. New data on a mechanically ventilated institutional building supplements similar studies made in residences.