• Proceedings of the KSR Conference
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• 2002.05a
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• pp.549-554
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• 2002

Recently, interest in hygiene has been arouse in the health care field. Consequently, Filters with antibacterial agent applied to improve air quality by sterilizing bacteria, fungi, etc. We actually installed antibacterial air filter containing 2.5wt%Ag zeolite on the air intake route to air-conditioner in passenger cu, and evaluated filter's performance on antibacterial effect. By the microbe liquid spattering method, we found that the antibacterial air filter has notably sufficient antibacterial efficiency against standard strains and wild type strains. Antibacterial effect was observed at whole area of filter media by zone of inhibition test. The evaluation of microbe quantity was conducted through mixing dilution plate culture method. In comparison with ordinary filter, the amount of germs attached on antibacterial air filters was larger. The amount of germs attached on ordinary filters was very small since ordinary filters contained less dust. In comparison in antibacterial air filter with thickness, the amount of germs attached on 9mm filter was smaller than that of on 6mm filter. i.e. thicker filter, superior efficiency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.114-117
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• 2006

The air filter in engine intake system has a function of filtrating the dirt in the scavenging air as well as attenuating the noise. The noise attenuation within the air cleaner filter, however, has been regarded as negligible by the field engineers. In this paper, for the analysis of the acoustical performance of air filter, an acoustical model was suggested and the characteristics of air filter system were investigated. Fibrous structure of the filter element was modeled as a micro-perforated panel using the flow resistivity and porosity. The pleated geometry of the filter element was modeled as two coupled ducts that have permeable walls, in which each duct area was assumed being constant. Using such simplified geometry, a mathematical model was developed for the sound propagation within a narrow duct system. Visco-thermal effect was considered in modeling the sound propagation through such tubes; the filter box was modeled as a rigid rectangular box. By combining two models, a four-pole transfer matrix was derived. For the validation purpose, transmission loss was measured for a plastic rectangular box containing an air filter. A noticeable effect of the air filter element was observed by including the filter into the box. Comparing the predicted and measured data, we found that the predicted TL agrees well with experimental results, in particular, in magnitude and frequency at TL troughs.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.1
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• pp.8-15
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• 2004

Since the vehicle is regarded as the third living space, the comfortable conditions are required in the passenger compartment. For this reason, customers are concerned about the filtering performances and the importance of filter media has been greatly placed. Therefore the dust holding capacity, the efficiency of these filter media (dry paper, wet paper, non-woven) and the configuration of air filter for vehicle were measured in this study. The following results were obtained on the basis of air filter test. It shows that the thickness and poresize of filter media should be lower for the higher efficiency. The measurement result shows that the performance of round shape filters are higher than the square shape filters. The dust holding capacity of the wet paper and the non-woven paper is higher than the dry paper. As a result, this research can provide an important design parameter and product guidance of the intake air filter for vehicular engine.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1227-1233
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• 2004

Air handling unit (AHU)'s air filter pressure difference is important for energy consumption and indoor air quality. Both energy Performance data and air filter differential pressure of AHU in real office buildings were monitored and analyzed to investigate quantitatively energy impact as dust buildup level on air filter grows. We also modeled and simulated CAV system using HVACSIM＋ program to examine the energy effect of dust buildup on filters. Through analysis of time series pressure drop data, the filter pressure difference rate has been increased due to cumulative supply air flow rate increase. As filter pressure drop increased to 1 inch water column, it is found that the supply air flow rate was decreased by 10%, the chilled water flow rate was increased by 5.9% and the pump energy consumption was increased to 5.9%.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1297-1301
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• 2007

The indoor air quality guideline of public transportation means was prepared recently. therefore we consider a countermeasure for the indoor air quality improvement of public transportation means. In this work, air-cleaner with roll filter system which developed alternative of indoor air quality guideline. The develpoed roll filter system is two function. the first function harmoniously circulated to heating and cooling air through HVAC system and secondary function removed PM(particluatie matters) which re-scatting to passenger's movement and suppled from outdoor air. Filter media of roll filter system select optimum electret mesh filter out of many filter media. Selected filter media was performanced tests of pressure drop, collection efficiency and dust holding capacity. Finally developed roll filter system was performanced bench test.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.436-441
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• 2009

An air filter is a device to remove dust from the air supplied to the automotive engine. A requirement for the optimum air filter is to improve the capability to remove particles from the air it takes in, that is the efficiency and amount of dust collection. By removing dust from the air, the air filter prevents the engine cylinder from wear, reduces ventilation resistance, and thus improves engine output and guarantees intake performance. In order to guarantee such air filter performance, it is very important to properly seal the air filter. For passenger cars made in Korea, the air filters are fabricated with steel caps as their frames are large and their engine capacity is big. Recently however, European countries and Japan started using urethane for manufacturing the air filter, so that all foreign-made cars now have urethane filters. The urethanes used for air filters are applied in two ways: One is to use soft urethane for both top and bottom of the air filter and the other is to use soft urethane for the top and hard urethane for the bottom. Each of these method has unique problems. In this study, hard urethane is used for both top and bottom of the filter in order to improve those problems and increase the sealing efficiency. Especially for the top, NBR (rubber mold) is pre-settled in tough urethane and then the urethane is solidified through foaming, which makes it possible to develop a solid and double-sealed filter.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.6
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• pp.644-655
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• 2012

As soon as a new air filter is applied to an air purification process, the filter gets loaded with dust particles. Thus, the study on the particle loading characteristics of air filter is very essential in order to understand the real filtration phenomena during filter use. In this study, we investigated the effect of particle and filter charge on the particle loading property of air filter. Charged filter and uncharged filter prepared by discharging the charged filter by isopropyl alcohol were used as test samples, and three types of particle having different charge states were supplied to filters tested. For neutralized particles there was a big difference in areal mass loading rates between charged and uncharged filters due to the very small amount of particle charge, on the other hand the difference was diminished for atomized particle and finally almost vanished for corona charged particles. The pressure drop of filter loaded with corona charged particles was only half of those for neutralized and atomized particles at the same areal mass loading because of the porous structure of particle deposit formed on filter fibers, caused by the space charge effect between particles.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.190-193
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• 2005

The air filter in engine intake system filters the dirt in the breathing air but also it attenuates the noise although the phenomenon has been regarded negligible. For the analysis of the acoustical performance of air filter, an acoustical model is suggested in this paper. The air filter consists of a porous filter element, which catches the particulate dirt, and a plastic filter box, which supports the filter element. Fibrous structure of the filter element is modeled as a micro-perforated panel using the flow resistivity and porosity. The pleated geometry of the filter element is modeled as two coupled ducts and a mathematical model is developed for the analysis of sound propagation. The filter box Is modeled as a rigid rectangular box. By combining two models, a 4-pole transfer matrix for the air filter is derived. The transmission loss calculated using the transfer matrix of the suggested model is compared with the measured data. Reasonably good agreement is observed. The result can be improved by considering the visco-thermal effect in modeling, in particular at a frequency range near the troughs of TL curve.

• Particle and aerosol research
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• v.12 no.4
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• pp.151-159
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• 2016

Since airborne viruses have been known to aggravate indoor air quality, studies on development of anti-viral air filter increase recently. In this study, a mass aerosol particle generator for coating a commercial air filter (over $300{\times}300mm^2$) was built, and evaluated by comparing a commercial particle generator. Then, via this device, a commercial air filter was coated with anti-viral material ($SiO_2-Ag$ nanoparticles in this study), so fabrication of commercial anti-viral air filter was performed and the pressure drop, filtration efficiency, and anti-viral ability of the filter were evaluated against aerosolized bacteriophage MS2 in a continuous air flow condition. The result showed that the particle generation of the new generator was more than about 8.5 times over which of the commercial one. Consequently, $SiO_2-Ag$ particle coating on a filter does not have significant effects on the filtration efficiency and pressure drop with different areas, and the average anti-viral efficiency of the $SiO_2-Ag$ filter was about 92% when the coating areal density was $1.0{\times}10^{12}particles/m^2$.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.19-24
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• 2009

This study was conducted to provide fundamental data for design of air inflating apparatus of air-inflated double-layer plastic greenhouse. The variation of static pressure in air tube for different fans and filters, filtering performance for various kinds of filters and destruction phase of experimental greenhouse collapsed by excessive static pressure in air space were analyzed. The general type of forward centrifugal fan was recommended for inflating air space in air-inflated double-layer plastic greenhouse. The experimental greenhouse was collapsed down by excessive static pressure just like fallen by heavy snow load acting on it. The static pressure in air tube without filter decreased linearly as the number of outlet openings increased. But the pressure in air tube with filter declined quadratically, the decremental ratio diminished by the increase of outlet openings. The higher filtering efficiency and the greater decrements of static pressure in air tube, the larger capacity fan was required for maintaining proper static pressure in air space. Because the porosities of filter were blocked by dust as time goes by, the static pressure in air tube with filter decreased. The higher filtering efficiency, the less decremental ratio of static pressure in air tube as time passes by. Considering the filtering efficiency, decrement of static pressure and thickness of filter, the 5mm thickness filter of 75% efficiency was recommended for air inflating filter of air-inflated double-layer plastic greenhouse.