Air Delivery Research Articles

Variation of clean air delivery rate and effective air cleaning ratio of room air cleaning devices

Air cleaners have been normally used to remove airborne particles from indoor air, and these devices are normally rated according to their clean air delivery rate (CADR), which is a measure of the delivery of contaminant-free air. This study evaluated and compared the performance of room air cleaning devices in removing submicron-sized particles. Most of the CADRs that were experimentally obtained were lower than that stated by the manufacturer. The difference between the experimental measurements and the device specifications gradually increases as the CADR increased. For the same air cleaning device, the experimental CADR decreased as the size of the test chamber increased. The effective air cleaning ratio (EACR) was newly defined to provide an accurate measure of the CADR. The EACR is the ratio of the real CADR to the stated CADR. The experiments and simulations revealed that the EACR of the air cleaning devices was in the range of 0.70–0.83. The ECAR is little changed with respect to the size of the test chamber and the flow rate of the air cleaning devices, unlike the experimental CADR. The real CADR is affected by the filtration efficiency, the flow rate, and the design of the air cleaning device as well as the size of the test particles. The real CADR decreases as the particle size increases. Therefore, the recommended CADR of air cleaning devices for use in facilities with sensitive populations or hospitals must be higher than that for general purpose use.

Stabilization of polymer electrolyte fuel cell voltage with reduced-order Lyapunov exponent feedback and corrective pressure perturbations

Polymer electrolyte fuel cell (PEFC) system efficiency can be decreased by instabilities resulting from the accumulation of water in the cathode as well as by excessive air delivery parasitic loads used to prevent liquid water accumulation. In this work, we present a new instability detection diagnostic tailored for the nonlinear and chaotic dynamics of PEFC operation with multi-phase flow in the gas channels. The instability statistic, the Lyapunov exponent of the reduced-order voltage return map, λ, is a measure of the exponential rate of divergence in the dynamic voltage signal measured from the fuel cell. A key advantage of this statistic for embedded control is that it is a self-referencing measure of the system stability for feedback and is not based on an a priori performance threshold. Our experiments demonstrate that the Lyapunov exponent statistic provides a warning typically 100 s in advance of significant power loss. Using this statistic as a control diagnostic, a new control scheme that detects PEFC instability in real time and mitigates it with pressure perturbations was applied experimentally to several fuel cell systems, including one that simulates stack operation. Our control scheme resulted in increased PEFC power, decreased cathode flooding leading to a lower parasitic load for air delivery, and stable PEFC performance.

Design of a High-Efficiency Minimum-Torque-Ripple 12-V/1-kW Three-Phase BLDC Motor Drive System for Diesel Engine Emission Reductions

A 12-V motor drive system using an onboard battery is promising in vehicle applications, e.g., to rotate an air pump to adjust its air delivery to the burner, thereby providing autonomous exhaust temperature control for the conventional diesel engine vehicle. The 12-V/1-kW motor drive system proposed in this paper consists of a series-resonant LLC MOSFET full-bridge converter, which provides high-efficiency power transfer by implementing zero voltage switching and boosts the dc bus to ~300 V, and an insulated-gate bipolar transistor inverter, which provides the high-side phase currents to a 1-kW/6000-r/min brushless dc motor (BLDC). This design secures the high efficiency, low cost, and low volume. Meanwhile, with the variable output voltage of this dc/dc converter, this paper realizes a commutation torque-ripple reduction method, which will minimize the mechanical vibration. Experimental results on this prototype system demonstrate that: 1) the LLC dc/dc part efficiency is 97.6% with 92% of the inverter efficiency; and 2) the motor commutation torque ripple is reduced close to zero.

Exploring express delivery networks in China based on complex network theory

Based on the complex network theory, we explore an express delivery system in China, which consists of two delivery networks, namely, the air delivery network (ADN) and the ground delivery network (GDN). Systematic structural analysis indicates that both delivery networks exhibit small‐world phenomenon, disassortative mixing behavior, and rich‐club phenomenon. However, there are significant differences between ADN and GDN in terms of degree distribution property and community structure. On the basis of the Barabási‐Albert model, we have proposed a network model incorporating the structural features of the two delivery networks to reveal their evolutionary mechanisms. Lastly, the parcel strength and the distance strength are analyzed, which, respectively, reflect the number of parcels and the long‐haul delivery distance handled by a node city. The strengths are highly heterogeneous in both delivery networks and have intense correlations with topological structures. These works are beneficial for express enterprises to construct or extend their express delivery networks, and provide some useful insights on improving parcel delivery service. © 2014 Wiley Periodicals, Inc. Complexity 21: 166–179, 2015

The Effect of Cathode Pressure Perturbations on the Voltage Stability of a Simulated Fuel Cell Stack

Current strategies for mitigating power loss due to cathode flooding in polymer electrolyte fuel cells are aimed at avoiding the unstable two-phase slug flow regime in the air delivery microchannels by delivering parasitically expensive excessive air flow rates. In this work, we investigate ways to stabilize the slug flow regime and recover voltage by applying low cost cathode pressure perturbations. We experimentally investigate the voltage response to the magnitude and frequency of pressure perturbations applied to a simulated fuel cell stack. The results are applicable to active fuel cell water management.

Experimental investigation of the formaldehyde removal mechanisms in a dynamic botanical filtration system for indoor air purification

Botanical filtration has been proved to be effective for indoor gas pollutant removal. To understand the roles of different transport, storage and removal mechanism by a dynamic botanical air filter, a series of experimental investigations were designed and conducted in this paper. Golden Pothos (Epipremnum aureum) plants was selected for test, and its original soil or activated/pebbles root bed was used in different test cases. It was found that flowing air through the root bed with microbes dynamically was essential to obtain meaningful formaldehyde removal efficiency. For static potted plant as normally place in rooms, the clean air delivery rate (CADR), which is often used to quantify the air cleaning ability of portable air cleaners, was only ∼5.1m3/h per m2 bed, while when dynamically with air flow through the bed, the CADR increased to ∼233m3/h per m2 bed. The calculated CADR due to microbial activity is ∼108m3/h per m2 bed. Moisture in the root bed also played an important role, both for maintaining a favorable living condition for microbes and for absorbing water-soluble compounds such as formaldehyde. The role of the plant was to introduce and maintain a favorable microbe community which effectively degraded the volatile organic compounds adsorbed or absorbed by the root bed. The presence of the plant increased the removal efficiency by a factor of two based on the results from the bench-scale root bed experiments.

Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen.

More than a metric ton of water is transported to the International Space Station (ISS) each year to provide breathing oxygen for the astronauts. Water is a safe and compact form of stored oxygen. The water is electrolyzed on ISS and ambient pressure oxygen is delivered to the cabin. A much smaller amount of oxygen is used each year in spacesuits to conduct Extra Vehicular Activities (EVAs). Space suits need high pressure (>1000 psia) high purity oxygen (must meet Aviator Breathing Oxygen specifications, >99.5% O2). The water / water electrolysis system cannot directly provide high pressure, high purity oxygen, so oxygen for EVAs is transported to ISS in high pressure gas tanks. The tanks are relatively large and heavy, and the majority of the system launch weight is for the tanks and not the oxygen. Extracting high purity oxygen from cabin air and mechanically compressing the oxygen might enable on-board production of EVA grade oxygen using the existing water / water electrolysis system. This capability might also benefit human spaceflight missions, where oxygen for EVAs could be stored in the form of water, and converted into high pressure oxygen on-demand. Cerium oxide solid electrolyte-based ion transport membranes have been shown to separate oxygen from air, and a supported monolithic wafer form of the CeO2 electrolyte membrane has been shown to deliver oxygen at pressures greater than 300 psia. These supported monolithic wafers can withstand high pressure differentials even though the membrane is very thin, because the ion transport membrane is supported on both sides (Fig 1). The monolithic supported wafers have six distinct layers, each with matched coefficients of thermal expansion. The wafers are assembled into a cell stack which allows easy air flow across the wafers, uniform current distribution, and uniform current density (Fig 2). The oxygen separation is reported to be infinitely selective to oxygen [1] with reported purity of 99.99% [2]. Combined with a mechanical compressor, a Solid Electrolyte Oxygen Separator (SEOS) should be capable of producing ABO grade oxygen at pressures >2400 psia, on the space station. Feasibility tests using a SEOS integrated with a mechanical compressor identified an unexpected contaminant in the oxygen: water vapour was found in the oxygen product, sometimes at concentrations higher than 40 ppm (the ABO limit for water vapour is 7 ppm). If solid electrolyte membranes are really infinitely selective to oxygen as they are reported to be, where did the water come from? If water is getting into the oxygen, what other contaminants might get into the oxygen? Microscopic analyses of wafers, welds, and oxygen delivery tubes were performed in an attempt to find the source of the water vapour contamination. Hot and cold pressure decay tests were performed. Measurements of water vapour as a function of O2 delivery rate, O2 delivery pressure, and process air humidity levels were the most instructive in finding the source of water contamination (Fig 3). Water contamination was directly affected by oxygen delivery rate (doubling the oxygen production rate cut the water level in half). Water was affected by process air humidity levels and delivery pressure in a way that indicates the water was diffusing into the oxygen delivery system.

Optimization of Surface Roughness in Micro-High Speed End Milling of Soda Lime Glass Using Uncoated Tungsten Carbide Tool with Compressed Air Blowing

Soda lime glass is a very important material in diverse manufacturing industries, including automotive, electronics, and aerospace. In these applications, the glass surface needs to be defect free and without impurities. However, the machining of glass is difficult due to its inherent brittleness which leads to brittle fracture and easy crack propagation. This research investigates the high speed micro-end milling of soda lime glass in order to attain ductile regime machining. It has been found by other researchers that ductile mode machining can avoid brittle fracture and sub-surface cracks. Also, in this study, a special air delivery nozzle is used to blow away the resultant chips and keep the machined surface clean. To accomplish this, Design Expert software and a commercial NC end mill were used to design and perform the machining runs, respectively. The surface roughness of the resultant surfaces was later analyzed with a surface profilometer. Microphotographs of the machined surfaces were also taken in order to see how effective the air blowing method is. The results of surface roughness measurements were then used to develop a quadratic empirical model for surface finish prediction. Finally, desirability function and genetic algorithms were used to predict the best combination of cutting parameters needed to obtain the lowest surface roughness. The predictions were later tested by experiments. The results demonstrate that this type of machining is viable and the roughness obtained is very low at 0.049 μm.

Flue Gas Emissions from the Burning of Asphaltite and Lignite in a Rotating Head Combustor with Secondary Air Delivery

In this work, a rotating head combustor, which has been designed for burning the coking coals effectively, was deployed to burn a range of coals available in Turkey under agitation conditions with secondary air delivery. The coals were lignite (Tunçbilek, Turkey) and asphaltite with high swelling property known as coking coal (Şırnak, Turkey). The performance was investigated by determining the temperature distribution on the head, combustion efficiency, and the amount of unburned substances (such as C) in the ash, and flue gas emissions of O2, CO, CO2, SO2, and NOx were measured during the experiments. The effect of operating conditions such as excess air ratio (EAR) and coal feeding rate was also investigated. The temperature distribution on the head was found to be high in the case of using the secondary air delivery and combustion efficiency was above 80% at the EAR of 1.3 and coal feeding rate of 9 kg/h when asphaltite was used as the fuel in the rotating head combustor. The comparison between asphaltite and lignite could lead to the conclusion that asphaltite provides slightly higher efficiency than lignite, and the difference is very small at the EAR of 1.3. When flue gas emissions are compared, it is seen that CO and SO2 emissions from asphaltite combustion are higher while CO2 and NOx emissions are lower than those derived from lignite combustion. For the combustion of both fuels, secondary air sent to the bed surface had a noticeable influence on combustion and emission characteristics via its effect on the combustion of volatility products and released gases from the bed surface. However, it should be more for lignite combustion in order to get better performance.

Comparing Air Delivery Methods in an Operating Theatre

Problem: The rate of surgical site infections (SSI) must be reduced. Hypothesis: Cleanroom air delivery mechanisms significantly reduce particle contamination and may help reduce SSI rates, increase positive clinical outcomes and improve energy cost savings. Objective: The primary objective of this study was to compare the ability of traditional operating room air delivery methods with those used in pharmaceutical and semiconductor cleanrooms to remove particle and microbial contamination from the sterile field.

Improved Combustion of Asphaltite Coals in a Rotating Head Combustor with Various Air Supply Arrangements

When burned in conventional stokers, coals with high swelling properties such as asphaltites make coke blocks (coking). The plastic layer formed on them prevents air from diffusing into coal; hence, the air provided for swollen coal to burn becomes insufficient. This problem can partially be resolved by shaking the flame bed automatically or by mixing the burning coals manually in order to provide continuous air for the surface of the unburned coal. Therefore, in this study, a coal combustion system with the rotating head was manufactured for burning effectively Turkish coking coals characterized by high sulfur and ash content in agitation conditions with air supply arrangements. This type of coals known as asphaltite, abundantly found in southeastern Anatolia coal basin in Turkey, were burned in the rotating head combustor in order to investigate the effect of operating parameters, such as excess air ratio, coal particle size and feeding speed, air delivery type, addition of flange, bed slope, and rotati...

Advanced Diagnostic Applied to a Self Breathing Fuel Cell Using Printed Circuit Board Technology

Fuel cells are currently been considered as promising alternatives for portable power applications (1-100 W) due to their good energy conversion efficiency, flat geometry, high power and the energy density of their fuel sources, making them advantageous over batteries [1]. The increasing importance of compact design for portable devices necessitates miniaturization of fuel cell stack components in order to maximize power density and for easy system integration [1]. In this study, an air breathing fuel cell has been developed using printed circuit board (PCB) technology. The use of PCBs affords cost-effective prototypes and design flexibility, which can help to reduce the cost of developing fuel cell stacks.In an open cathode or self-breathing fuel cell, supply of oxygen to the cathode is achieved through free or natural convection of air-flow. The output power densities of these type of fuel cells are typically low when compared with forced convection fuel cells [2]. However, they are still considered attractive options for portable application due to other key advantages over forced convection designs, such as simplicity of natural convection air delivery, lower cost, less noise and no pumps required. The cathode performance is usually the major source of voltage loss as a result of natural convection of air which can lead to mass transport limitations (Fig 1) and inadequate water removal. This work explores the use of advanced diagnostic techniques to understand the internal working of a novel self-breathing polymer electrolyte fuel cell. This includes the use of a thermal imaging camera to observe the production and distribution of heat (Fig 2 ) and direct visualization of open channels to observe water formation. The PEMFC fabricated consisted of two printed circuit board (PCB) current collectors (anode and cathode), an MEA, gaskets and two end plates. The PCB current collectors were were coated with conductive carbon ink for corrosion protection. The flow fields were machined onto the PCBs using a CNC milling machine. The gaskets used for gas manifolds were made of silicone. The cathode end plates were made from aluminium sheets and contained a 13cm2 window for direct visualization of the flow field. A double serpentine flow field was used for the anode. The cathode geometries employed were parallel and circular openings. The two cathode geometries employed will be compared using polarization curve and impedance spectrscopy.Polarization perfomance of the open cathode fuel cells have indicated mass transport limitation as the dominant source of voltage loss. The circular opening geometry also performs better than the parallel opening geomerty at the ohmic region of the curve but performance drops in the mass transport region. The impedance spectra obtained also points at severe mass transport issues especially with the circular openings. This is as a result of water bubbles blocking the path of air flow. Thermal imaging results indicates the existence of hotspots which is very important as the membrane could fail if the hotspot exceeds its maximum design limitation. The work presented will be of interest to both academic and industrial personell as it gives an indication of the stable operating points of air breathing fuel cell and also provides potential water management strategies.

Influence of the inlet air in efficiency of photocatalytic devices for mineralization of VOCs in air-conditioning installations

Nowadays, a large proportion of photocatalytic oxidation (PCO) devices are being implemented in heating, ventilation and air-conditioning systems. However, no systematic studies have been carried out regarding the influence of inlet air preconditioning. To analyse the impact of the inlet air-conditions into photocatalytic efficiency, a simulated air-conditioning duct with flowing gas through inside was designed. Isobutylene was chosen as the target VOCs. The concentration in the gas phase was monitored using a photoionization detector. The influence of flow rate, relative humidity and temperature on the VOC removal efficiency was analysed. Experimental results were presented in terms of gas-removal efficiency (η) and clean air delivery rate (CADR) and analysed on a kinetic basis. From them, the weight of each parameter in the global process has been determined, from bigger to smaller contribution, flow>>temperature>relative humidity. Also, the relevance of the inlet air conditions has been illustrated in a model room in order to determinate the time necessary to obtain a threshold value accomplishing with enough air quality and the energy consumption of the device. Additionally, the photocatalytic decontamination has been assimilated to the "air exchange rate", a parameter commonly used in indoor air quality studies. The results show that preconditioning of air can improve the efficiency of photocatalytic devices and bring important energy savings.

Prototype and Laboratory Low-Level Outlet Air Demand Comparison for Small-to-Medium-Sized Embankment Dams

AbstractLow-level outlet works through dams are typically used to provide irrigation, reservoir sediment flushing, reservoir draw down, and/or minimum downstream flows to meet biological needs. To reduce the likelihood of negative pressure development downstream of the control gate, which may lead to cavitation noise, vibration, and damage, air vents are typically installed downstream of the gate. Undersized air vents may allow vapor pressure and cavitation to occur; oversized air vents have a negative economic impact. Air demand design criteria have been developed for vertical control gates (common to larger dams). The guidance for sizing air vents for an inclined slide gate, which are common for small-to-medium-sized embankment dam geometries, however, is limited. This study compares laboratory-scale and prototype-scale air-demand data. The influences of conduit slope, hydraulic jump presence, and air delivery system geometry on air demand were found to influence air demand. A method for estimating the ...

Room Level Modeling of Air Flow in a Contained Data Center Aisle

Cold aisle containment is used in air cooled data centers to minimize direct mixing between cold and hot air. Here, we present room level air flow field investigation for open, partially and fully contained cold aisles. Our previous investigation for rack level modeling has shown that consideration of momentum rise above the tile surface, due to acceleration of air through the pores, significantly improves the predictive capability as compared to the generally used porous jump model. The porous jump model only specifies a step pressure loss at the tile surface without any influence on the flow field. The momentum rise could be included by either directly resolving the tile's pore structure or by artificially specifying a momentum source above the tile surface. In the present work, a modified body force model is used to artificially specify the momentum rise above the tile surface. The modified body force model was validated against the experimental data as well as with the model resolving the tile pore geometry at the rack level and then implemented at the room level. With the modified body force model, much higher hot air entrainment and higher server inlet temperatures were predicted as compared to the porous jump model. Even when the rack air flow requirement is matched with the tile air flow supply, considerable hot air recirculation is predicted. With partial containment, where only a curtain at the top of the cold aisle is deployed and side doors are opened, improved cold air delivery is suggested.

Obesity Elicits Interleukin 1-Mediated Deficits in Hippocampal Synaptic Plasticity

Adipose tissue is a known source of proinflammatory cytokines in obese humans and animal models, including the db/db mouse, in which obesity arises as a result of leptin receptor insensitivity. Inflammatory cytokines induce cognitive deficits across numerous conditions, but no studies have determined whether obesity-induced inflammation mediates synaptic dysfunction. To address this question, we used a treadmill training paradigm in which mice were exposed to daily training sessions or an immobile belt, with motivation achieved by delivery of compressed air on noncompliance. Treadmill training prevented hippocampal microgliosis, abolished expression of microglial activation markers, and also blocked the functional sensitization observed in isolated cells after ex vivo exposure to lipopolysaccharide. Reduced microglial reactivity with exercise was associated with reinstatement of hippocampus-dependent memory, reversal of deficits in long-term potentiation, and normalization of hippocampal dendritic spine density. Because treadmill training evokes broad responses not limited to the immune system, we next assessed whether directly manipulating adiposity through lipectomy and fat transplantation influences inflammation, cognition, and synaptic plasticity. Lipectomy prevents and fat transplantation promotes systemic and central inflammation, with associated alterations in cognitive and synaptic function. Levels of interleukin 1β (IL1β) emerged as a correlate of adiposity and cognitive impairment across both the treadmill and lipectomy studies, so we manipulated hippocampal IL1 signaling using intrahippocampal delivery of IL1 receptor antagonist (IL1ra). Intrahippocampal IL1ra prevented synaptic dysfunction, proinflammatory priming, and cognitive impairment. This pattern supports a central role for IL1-mediated neuroinflammation as a mechanism for cognitive deficits in obesity and diabetes.

A New Clean Air Delivery Rate Test Applied to Five Portable Indoor Air Cleaners

Air pollution has been recognised as one of the major risk factors for the global burden of disease. In modern society the majority of the exposure occurs indoors where people spend most of their time. Indoor air quality may be improved with portable air cleaners utilizing various cleaning techniques, such as filtration, electrostatic precipitation, and ionization. The objective of this study was to quantify air cleaner particle removal by particle size resolved clean air delivery rates (CADR). This was obtained by utilizing particle concentration measurements and indoor aerosol modeling. Our test protocol was applied to five air cleaners designed for household and office use. For particles with diameters above 100 nm and at the chosen settings, the CADR was around 40 m3/h for an ion generator, around 70 m3/h for an electrostatic precipitator, and ranging from 100 to almost 300 m3/h for the three filter-based air cleaners. Similar performances were obtained for ultrafine particles, except for the ion gene...

Ripening physiology and quality of ‘Hass’ avocado (Persea americana Mill.) after cold storage at 1ºC

SummaryThe export of avocado (Persea americana Mill.) fruit into foreign markets has become a high priority for the South African industry due to increased competition in the European market. Some of these countries require phytosanitary treatment before access is granted. Cold disinfestation is the only suitable phytosanitary treatment available for avocado, but the fruit are generally considered to be sensitive to temperatures below approx. 5ºC. Phytosanitary disinfestation of South African avocados of acceptable fruit quality has been achieved by maintaining the pulp temperature below 2ºC for 28 d, but the effect on ripening physiology has not been determined. The effect of cold storage at 1ºC (air delivery temperature) on ‘Hass’ avocados with or without modified humidity packaging (MHP) for 28 d was examined. Compared to a conventional storage temperature of 5.5ºC for 28 d, fruit stored at 1ºC had significantly reduced rates of respiration and ethylene production, less softening, water loss, fresh weight (FW) loss, and mannoheptulose consumption measured immediately after cold storage. The use of MHP resulted in similar reductions at the conventional temperature and, when MHP was used in combination with 1ºC storage, these reductions were enhanced. Cold storage at either temperature resulted in increased cellulase and polygalacturonase activities during ripening when compared to non-stored fruit (kept at 21ºC until ripe), but no significant differences were recorded between the four cold storage treatments (i.e., 1ºC and 5.5ºC, with or without MHP) in the activities of cellulase, polygalacturonase, and pectin methylesterase during ripening. The number of days to ripen increased slightly after storage at 1ºC, but the percentage of marketable fruit was not significantly reduced. Significantly reduced FW and water losses from fruit stored under MHP resulted in significant reductions in the severity of skin spotting. The ripening physiology and quality of South African ‘Hass’ avocados were not negatively affected when fruit were stored at 1ºC for 28 d. When considered with previous results, this treatment appears to be suitable for future use.

Adequacy of air change rate as the sole indicator of an air distribution system's effectiveness to mitigate airborne infectious disease transmission caused by a cough release in the room with overhead mixing ventilation: A case study

In indoor environments where airborne infectious disease transmission is of concern, air change rate is conventionally used as the sole indicator of air delivery system performance. This indicator, based on the total volume dilution reasoning, suggests that increase of the supply flow rate will reduce risk of airborne infectious disease transmission. Results obtained from recent studies on cough release conducted in the field environmental chamber (FEC) at the National University of Singapore indicate that increase of supply flow rate may cause increase in the airborne infection risk transmission for several positions of the cough source and the susceptible person in relation to the supply and return air grills. Particle image velocimetry (PIV) was used for airflow field investigation, while a Grimm 1.108 aerosol counter was used to measure droplet concentration in the FEC. Results from this study imply that a local airflow pattern is an important factor influencing dispersion of cough droplets and consequential exposure. It is demonstrated that increase in supply flow rate can lead to an increase in exposure under certain circumstances. This further implies that air change rate should not be used as the sole indicator of the air delivery system's ability to reduce exposure to airborne infectious droplets.

Performance Evaluation of Plasma Air Cleaning Systems with Ion Impactor Type Electrodes for Removing Yellow Sand Dust

Yellow sand dust (Asian dust storm) causes harmful damage to both indoor and outdoor environments during the springtime. Removal of Yellow sand dust has become an issue for suitable indoor conditions, and an air cleaner is required to remove it efficiently; thus, an analysis of its characteristics should be conducted. In this article, two types of plasma air cleaning systems based on the principle of electrostatic precipitation are evaluated using equivalent dust to Yellow sand dust. To study the influence of an electrode shape of precharger on the collection efficiency, we carried out experiments using a plate and an ion impactor type electrode. From the results, the discharge current was found to be higher for the ion impactor electrode than for the plate electrode. Also, the collection efficiency was greater with the ion impactor electrode than with the plate electrode. For the single-pass test, the removal efficiencies of Yellow sand equivalent dust at the face velocity of 1.0 m/s are greater than 80% with the plate and ion impactor electrodes. For the multi-pass test in occupied spaces, the operation time required to reduce Yellow sand dust concentration from the initial concentration of 300–150 µg/m3 (the criteria of indoor air quality), is 5 min for the ion impactor electrode and 7 min for the plate electrode. Also, the clean air delivery rate (CADR) value is 113 for the ion impactor electrode and 85 for the plate electrode. The plasma air cleaning systems are suitable for the removal of Yellow sand dust for maintaining suitable indoor air quality.