A New Dynamic and Vertical Photovoltaic Integrated Building Envelope for High-Rise Glaze-Facade Buildings

Substantially glazed facades are extensively used in contemporary high-rise buildings to achieve attractive architectural aesthetics.Inherent conflicts exist among architectural aesthetics,building energy consumption,and solar energy harvesting for glazed facades.In this study,we addressed these conflicts by introducing a new dynamic and vertical photovoltaic integrated building envelope(dvPVBE)that offers extraordinary flexibility with weather-responsive slat angles and blind positions,superior architectural aesthetics,and notable energy-saving potential.Three hierarchical control strategies were proposed for different scenarios of the dvPVBE:power generation priority(PGP),natural daylight priority(NDP),and energy-saving priority(ESP).Moreover,the PGP and ESP strategies were further analyzed in the simulation of a dvPVBE.An office room integrated with a dvPVBE was modeled using EnergyPlus.The influence of the dvPVBE in improving the building energy efficiency and corresponding optimal slat angles was investigated under the PGP and ESP control strategies.The results indicate that the application of dvPVBEs in Beijing can provide up to 131%of the annual energy demand of office rooms and significantly increase the annual net energy output by at least 226%compared with static photovoltaic(PV)blinds.The concept of this novel dvPVBE offers a viable approach by which the thermal load,daylight penetration,and energy generation can be effectively regulated.

Prediction and validation of diffusive uptake rates for indoor volatile organic compounds in axial passive samplers

The diffusive uptake rate is essential for using passive samplers to measure indoor volatile organic compounds(VOCs).The traditional theoretical model of passive samplers requires available regression formulas of uptake rates and physicochemical properties of adsorbents to predict the uptake rate.However,it is difficult to obtain the uptake rates of different VOCs under different sampling periods,and it is also difficult to obtain the physical parameters of adsorbents accurately and effectively.This study provides a reliable numerical prediction method of diffusive uptake rates of VOCs.The modeling was based on the standard automated thermal desorption(ATD)tubes packed with Tenax TA and the mass transfer process during adsorption.The experimental determinations of toluene uptake rate are carried out to verify the prediction model.Diffusive uptake rates of typical indoor VOCs are obtained from the literature to calibrate the key apparent parameters in the model by statistical regression fitting.The predicted model can provide the VOC diffusive uptake rates under different sampling duration with an average deviation of less than 5%.This study can provide the basis for fast and accurate prediction of diffusive uptake rates for various VOC pollutants in built environments.

A super sandstorm altered the abundance and composition of airborne bacteria in Beijing

Sandstorm,which injects generous newly emerging microbes into the atmosphere covering cities,adversely affects the air quality in built environments.However,few studies have examined the change of airborne bacteria during severe sandstorm events.In this work,we analyzed the airborne bacteria during one of the strongest sandstorms in East Asia onMarch 15th,2021,which affected large areas of China and Mongolia.The characteristics of the sandstorm were compared with those of the subsequent clean and haze days.The composition of the bacterial community of air samples was investigated using quantitative polymerase chain reaction(qPCR)and high-throughput sequencing technology.During the sandstorm,the particulate matter(PM)concentration and bacterial richnesswere extremely high(PM_(2.5):207μg/m^(3);PM_(10):1630μg/m^(3);5700 amplicon sequence variants/m^(3)).In addition,the sandstorm brought 10 pathogenic bacterial genera to the atmosphere,posing a grave hazard to human health.As the sandstorm subsided,small bioaerosols(0.65–1.1μm)with a similar bacterial community remained suspended in the atmosphere,bringing possible long-lasting health risks.

A new pin-to-plate corona discharger with clean air protection for particulate matter removal

High concentration particulate matter(PM)has been a serious environmental problem in China and other devel-oping countries.Electrostatic-based purification technology is a method to remove airborne particles,and can reduce the energy consumption of ventilation fans in buildings because of its low pressure drop.In this study,we developed a new pin-to-plate corona discharger with particle-free external air protection to prevent particles polluting the surface of discharge pins.By using an optical microscope,we observed a certain number of parti-cles deposited on the non-protected(exposed pins)and few particles deposited on the protected pins after they operating for 3 weeks.We experimentally studied the long-term performances of the exposed and protected pins in single-pass PM removal efficiency and ozone production.The results showed that the protected pins produce less ozone and have higher breakdown voltage than the exposed pins.Experimental results indicated that the im-proved pin-to-plate corona discharger has better long-term performance and is safer than the exposed one.The results of the research can give an understanding of how to improve electrostatic-based purification technologies toward stable discharging for high removal efficiency of particles.

Design and performance of a novel miniaturized electrostatic sampler for efficient airborne particulate matter sampling

Considering that people spend more than 80%of their time indoors,ambient particulate matter(PM)in the built environment could pose severe environmental health risks to public health.PM sampling,a technique for the enrichment of PM in the air,is essential for ambient PM composition analysis to understand its environmental and health effect.The filtering method that is widely used features a complex post-processing and carries the risk of pore clogging.It is a great challenge to sample airborne PM efficiently for subsequent analysis.Here,we proposed a novel miniaturized electrostatic sampler based on corona discharge and a modified vertically focused electric field for efficient PM sampling.Four intercoupling physical fields in the developed sampler were analyzed,including corona discharge,airflow,particle charging and particle deposition.The collection efficiencies for particles with various sizes(0.01–10μm)were conducted by simulation and the lowest efficiency occurs at about 0.3–0.5μm.With an increase in discharging voltage from−6 kV to−9 kV,the lowest efficiency rises from 88.2%to 96.6%.An electrostatic sampler entity was manufactured to test the collection efficiency of PM and the results are in good agreement with the simulation.The induced ring plate can significantly improve the total collection efficiency from 35%to 90%under−6 kV discharging voltage in the experiment.The novel electrostatic sampler exhibits potential and enlightenment for efficient and convenient PM sampling.

建筑空气环境人因工程学:问题、思考与探索

人80%以上时间在室内度过,室内空气环境质量对人的健康、舒适和工作效率有重要影响.采用节能低碳方式营造健康舒适的室内空气环境是“健康中国”与“双碳”目标国家战略的重要内容.传统的建筑空气环境研究范式存在以下不足:人的热舒适状况主要基于主观感受调研,人的健康状况主要基于患病率调研;空气环境监测参数在种类、时空分布上非常有限;传统室内空气热质过程优化主要基于工程热力学和传热传质学,前者仅适用于平衡态下的热-功转换过程,后者虽有强化概念但缺乏优化概念,在确定建筑环境涉及湿和多种污染物的非平衡态热-质-功的复杂过程优化时遇到实质性困难.

减少中国快速发展城镇的室内暴露健康风险

[背景]在过去的20年,中国人口从农村向城镇大迁移。与此同时,城市住宅的特征已经发生变化,从单层或低层建筑变为高层建筑,并用许多合成材料建造和装配。其结果是室内暴露(源于室外和室内的污染物)显著改变。[目的]本文简要讨论了中国城镇化和现代化建设已经对室内暴露和公众健康产生的可能影响,旨在论证日益增加的、与这些变化相关的不良医疗费用并非不可避免,并提出降低室内有害污染物暴露所能采取的措施。[讨论]正如中国卫生部所记录的,在过去20年间城镇居民的发病率和死亡率显著增加。有证据表明,人群空气污染物暴露已经导致肺癌、心血管疾病、肺部疾病和出生缺陷的增加。无论污染物来源于室外或室内,大多数的污染物暴露发生在室内。今后,人们可以通过限制室外污染物侵入(同时充分通风提供清洁空气),尽量减少室内来源的污染物,更新与室内污染相关的政府政策,以及在建筑物设计之初注重室内空气质量等措施来减少室内暴露。[结论]采取上述建议的措施可能会显著降低发病率和死亡率,大大降低污染物所致不良健康事件相关的社会成本。