Evaluation of clean air delivery rates and operating cost effectiveness for room air cleaner and ventilation system in a small lecture room

Noh, K.C.,Yook, S.J. Elsevier Sequoia S.A 2016 Energy and buildings Vol.119 No.-

In general, room air cleaners are rated according to clean air delivery rate (CADR). However, ventilation systems have not yet been assessed using a metric similar to CADR. This study establishes a new mass balance equation that compares the CADRs of a ventilation system and a room air cleaner. Experiments and CFD simulations were conducted to evaluate and compare the CADRs of room air cleaners and ventilation system in the view of removing particles from indoor air. In addition, the operating cost effectiveness of ventilation system and room air cleaner was investigated. The results showed that the room air cleaners showed their performance independently, even when two or more room air cleaners were operated simultaneously. In the ventilation system, an air filter with MERV11 or higher rating was recommended to reduce the indoor particle concentration when 100% outdoor air was supplied. It was possible to select an air filter with MERV11or lower rating when the recirculation airflow rate was increasing up to 70%. The CADR of the room air cleaner was higher than that of the ventilation system regardless of the particle size and the filter performance when the airflow rate was same. The operating cost effectiveness (CADR/kW) of the room air cleaner was higher than that of the ventilation system at the same airflow rate. Therefore, the room air cleaner must be more cost-effective than the ventilation system for reducing particle concentration indoors.

서울 초등학교 교실의 PM_2.5 및 PM₁₀ 제거를 위한 학교용 공기청정기 실증

한방우,홍기정,신동호,김학준,김용진,김상복,김상우,황청하,노광철,Han, Bangwoo,Hong, Keejung,Shin, Dongho,Kim, Hakjoon,Kim, Yongjin,Kim, Sangbok,Kim, Sangwoo,Hwang, Cheongha,Noh, Kwangchul 한국입자에어로졸학회 2019 Particle and Aerosol Research Vol.15 No.2

It is important to control fine particles in children care centers, elementary schools, elderly care facilities and so on where vulnerable children and the aged stay during most of their time. This study has investigated $PM_{2.5}$ and $PM_{10}$ concentrations in two classrooms equipped with an air cleaner and two air cleaners, respectively and they were compared to those in a classroom without an air cleaner as well as those outdoors. Eight air cleaners which have various clean air delivery rates (CADRs) between 9.9 and $21.3m^3/min$ were tested in classrooms in two elementary schools in Seoul. Average $PM_{2.5}$ and $PM_{10}$ were $7.3{\pm}0.7$ and $45.5{\pm}4.1{\mu}g/m^3$ in classrooms equipped with an air cleaner and $4.2{\pm}0.6$ and $24.6{\pm}2.5{\mu}g/m^3$ in classrooms with two air cleaners, whereas they were $22.1{\pm}2.6$ and $109.1{\pm}9.6{\mu}g/m^3$ in classrooms without an air cleaner and $36.9{\pm}5.1$ and $74.1{\pm}10.6{\mu}g/m^3$ outdoors, respectively. $PM_{2.5}$ in classrooms could be reduced effectively by using an air cleaner or two air cleaners, because $PM_{2.5}$ was mainly infiltrated from outdoors, however $PM_{10}$ could not because $PM_{10}$ was mainly caused indoors by students' activities. Air cleaners were more effective for removal of $PM_{2.5}$ and $PM_{10}$ in classrooms with a high airtightness than those in classrooms with a relatively low one. Average $CO_2$ in classrooms was about 1500 to 2000 ppm for class hours dependent on the student number per a classroom, which was about 1.5 to 2 times higher than the standard, regardless of the use of air cleaner.

에너지소비를 고려한 실내공기청정기의 풍량별 입자 청정화능력 분석

한방우,강지수,김학준,김용진,원효식 한국입자에어로졸학회 2013 Particle and Aerosol Research Vol.9 No.3

The performances of indoor air cleaners including particle cleaning capacity and collection efficiency are usually tested at the condition of the maximum air flow rate of the air cleaners. However, the power consumption of the air cleaners is highly dependent on the air flow rate of the individual air cleaners. Therefore, there seems to be an optimized air flow rate for the air cleaning capacity considering power consumption. In this study, clean air delivery rate(or standard useful area as suggested room size) and power consumption have been investigated for different maximum air flow rates of 15 air cleaners and then compared those for different air flow rate modes of the individual 5 air cleaners selected from the 15 cleaners. For the maximum air flow rate conditions of 15 air cleansers, the power consumption per unit area was less related to the maximum air flow rate. However, for the different air flow rate modes of the selected 5 air cleaners, the lower power consumption per unit area was corresponding to the lower air flow rate mode of the individual air cleaners. When considering the operation time to the desired particle concentrations, there was an optimized one in the medium air flow rate modes for the individual air cleaners. Therefore, not only the maximum air flow rate but also lower air flow rates of individual air cleaners should be considered for estimating air cleaning capacity based on energy consumption per unit area.

실물실험을 통한 국내 공기청정기의 미세먼지(PM2.5) 제거 효율 평가

김기철,이윤규,어수미,권승미,김광래,이채린,박필주 한국냄새환경학회 2019 실내환경 및 냄새 학회지 Vol.18 No.1

This study was performed to assess particulate matter removal efficiency of domestic air cleaner products in afield condition. The assessment also included air cleaners with different air removal mechanisms. The particulatematter (PM2.5) removal test with a different air removal mechanism using air cleaners showed that the electrostaticprecipitation technique showed better performance compared with HEPA filters and other types of systems. Itsremoval efficiency was almost 95% in one of our operation times in the given test condition. It was assumed thatnot only the type of removal system but also the individual design, supply and exhaust system, and theautomatically controlled air volume are involved in the removal efficiency. With respect to the area of application,tests with air cleaners for 40 m2, 60 m2, and 80 m2 areas revealed that particulate matter removal efficiencyincreased with the air cleaner that had a broad area of application. However, particulate matter removal efficiencyby air cleaners did not correspondingly increase with the increase of the area of application. Moreover, theinstallation location did not influence particulate matter removal efficiency. Our results are expected to be usedas the basic information for indoor air quality improvement and prediction using air cleaners.

실내 환경 관리기술의 청정화능력 및 비용-효과에 대한 이론적 고찰

노광철 한국냄새환경학회 2015 실내환경 및 냄새 학회지 Vol.14 No.2

Ventilation devices and room air cleaners can be used to remove indoor contaminants from indoor air. Generally, room air cleaners are rated according to clean air delivery rate (CADR). However, a similar metric for ventilation has not been used to be compared with CADR of room air cleaner. The CADRs and cost-effectiveness metrics (CADR/kw) of ventilation devices and room air cleaners were newly defined and theoretically compared for a child care center. The results indicate that the CADRs of room air cleaner were greater than that of ventilation. A higher collection efficiency for the particles guaranteed a higher CADR for ventilation. Ventilation filter had a performance that exceeds MERV11 should be used to effectively control the indoor particle concentration. The stand alone type air cleaner was found to have the best performance in the cost-effectiveness. The reason for this is that the effective air cleaning ratio of the stand alone type air cleaner is higher than that of the others and the power consumption of the stand alone type air cleaner is lowest.

Effect of an Air Cleaner with Electrostatic Filter on the Removal of Airborne House Dust Mite Allergens

Santosh Rani Agrawal,김학준,이용원,손정호,이재현,김용진,이성화,홍천수,박중원 연세대학교의과대학 2010 Yonsei medical journal Vol.51 No.6

Purpose: The effects of air cleaners on the removal of airborne indoor allergens,especially house dust mites (HDM), are still controversial. The objective of this study is to evaluate the effect of an air cleaner with an electrostatic filter on the removal of airborne mite allergens. Materials and Methods: A dried HDM culture medium that contained mite body particles and excretions was dispersed in a chamber equipped with an electrostatic air cleaner. The number of airborne particles was recorded continuously by a dust spectrometer for 60 minutes. Airborne particles in the chamber were collected on a sampling filter at a flow rate of 10 L/min and the Der f 1 concentration in the filter extracts was measured by two-site ELISA. Results: The air cleaner efficiently removed airborne HDM particles. The air cleaner removed airborne HDM particles (size 2-12.5 μm) 11.4 ±2.9 fold (cleaner operating for 15 minutes), 5.4 ± 0.7 fold (cleaner operating for 30minutes), and 2.4 ± 0.2 fold (cleaner operating for 60 minutes) more than the removal of HDM particles by natural settle down. Removal kinetics differed according to the particle size of the airborne particles. The air cleaner decreased the concentration of Der f 1 in the extraction of airborne particles collected on the air sampling filter by 60.3%. Conclusion: The electrostatic air cleaner can remove airborne HDM allergens and may be useful as a supplementary environmental control tool for HDM sensitized respiratory allergic patients.

자동차용 공기청정기의 성능 평가 및 설치 조건 도출을 위한 수치해석적 연구

이용훈(Y.H. Lee),서진원(J.W. Seo),박재홍(J.H. Park),최윤호(Y.H. Choi) 한국전산유체공학회 2010 한국전산유체공학회 학술대회논문집 Vol.2010 No.5

In this study, an air cleaner is considered to improve comfort, safety, and health of automobile passengers. The performance and installation conditions of the air cleaner have been studied to investigate their effects on the air quality in the cabin room using numerical analysis. A five-passenger sedan and a seven-passenger minivan that have comparatively large indoor volume have been considered. The distributions of the local mean age and the volume averaged age of indoor air are calculated according to the variation of the placement and the air flow of the air cleaner. In addition, a decrease of contamination concentration, especially VOCs(volatile organic compounds), by the air cleaner is numerically analyzed with time-accurate unsteady calculation to quantify the effect of the air cleaner on the indoor air quality. As a result, the effective installation and operation conditions of the air cleaner for the automobile cabin room could be suggested.

차량용 에어클리너의 A/S 편의성 향상을 위한 새로운 구조의 서랍식 에어클리너 개발 및 엔진룸 내 공간 활용의 최적화

신평수(Pyeongsu Shin),조청용(Cheongyong Cho),박영선(Youngsun Park) 한국자동차공학회 2017 한국자동차공학회 학술대회 및 전시회 Vol.2017 No.11

The space of the engine room is getting complicated because of the advancement of functions applied to automobiles, the number of parts is increasing and becoming larger. Therefore, the space required for the air cleaner is reduced, and the A / S convenience is also poor. So, it is necessary to develop a drawer type air cleaner. By brainstorming, we designed a new cam shaft drawer type air cleaner and verified new idea through concept design and application of actual car. In the drawer type air cleaner market, which has been dominated by advanced companies, securing the unique technology of the new drawer type air cleaner will prove the superiority of our technology and the opportunity for customer expansion will increase.

가정집 공기청정기 필터에 존재하는 진균의 농도 및 종 조사

안금란,김수산,강정아,김성환 한국냄새환경학회 2019 실내환경 및 냄새 학회지 Vol.18 No.3

The use of air cleaners has become popular to quickly remove contaminants present in indoor air such as fine dust and fungi. However, fungal information is rarely available in the filters equipped in the air cleaners. This study was conducted in winter to examine fungal concentration and species in the air cleaner filters of ten residential houses located in Incheon, Seoul, Hwaseong, and Gimpo cities. Fungi were detected in nine out of eleven filters from the ten houses. The level of fungi in the filters ranged from 0 CFU/cm2 to 2,370 CFU/cm2. There were differences in the fungal concentration among the eleven filters. Filters from three houses revealed levels over 1,000 CFU/cm2. The operation time of air cleaners did not seem directly related to the level of fungal concentration. A total of 326 isolates were obtained and classified as six genera belonging to Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium, and Trichoderma. Among these six genera, 20 species including one Alternaria, one Aspergillus, three Cladosporium spp., two Fusarium spp., eleven Penicillium spp., and two Trichoderma were identified. There were species that cause allergic reaction, pneumoniae, mycosis, and plant disease. Three species were known species of mycotoxin producers. Aspergillus niger, Cladosporium cladosporioides, and Penicillium brevicompactum were the most frequently detected fungi both in the air and in the air cleaner filters. This is the first report of fungal communities present in the air cleaner filters of residential houses in Korea.

공기청정기의 구조형상에 따른 소음과 청정화능력 특성 비교연구

홍기정,이건희,박인용,김상복,박대훈,김학준,김용진,이예완,김진태,정상현,심성훈,한방우 한국냄새환경학회 2021 실내환경 및 냄새 학회지 Vol.20 No.4

High concentrations of fine particles are increasingly being detected due to inflows from abroad and local emission sources in Korea. As most people spend about 90% of their time indoors, the use of indoor air cleaners has grown significantly as they are now thought to be essential items. In this study, the noise, power consumption, and clean air delivery rate (CADR) of commercial air cleaners were analyzed according to the structural shape of the air cleaners. Analyses were performed based on the experimental results of 249 cases for air cleaners certified by Korea Air Cleaning Association. The air cleaners with front inlet and upper outlet air flow direction, which currently account for the highest market share, were found to have the highest noise per CADR (dB(A)/(m3/min)). On the other hand, the air cleaners with the inlet and outlet air flow in the same horizontal direction were found to have lowest noise per CADR than other structures.