• Title/Summary/Keyword: Ventilation

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The Effect of Paper Permeability on Cigarette Properties (종이의 투기도가 담배 물성에 미치는 영향)

  • 김영호;한영림;이문용;이영택;김정열
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.1
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    • pp.64-72
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    • 2001
  • The cigarette ventilation affects not only the amount of tar and nicotine delivery by a cigarette, but also the composition of the smoke. Therefore, it is important to stabilize of variability in cigarette ventilation that would be affected by changes in cigarette components. This work was conducted to determine the major factors that influence the cigarette ventilation and also to provide fundamental informations for improving the uniformity of cigarette performances. To evaluate the effect of cigarette ventilation as a dependant variable, the three independent factors were the air permeability of plugwrap, tipping paper and the filter pressure drop. We determined the effect of paper permeability on ventilation variability and the optimum condition in combinations of independent factors. The mean of cigarette ventilation was increased as plugwrap permeability increases, particularly at 26,000 CU. However, it was exhibited that standard deviation and coefficient of variation of the cigarette ventilation were decreased with increasing plugwrap permeability. At the 600 CU and 1,200 CU of tipping paper permeability, process capability index (Cp) of the cigarette ventilation increased as plugwrap permeability increases. Following the optimum condition of cigarette ventilation induced by fitted regression equation, one was to optimize 50% ventilation level is by combination with plugwrap permeability of 16,000 CU, tipping paper permeability of 810 CU, filter pressure drop of 319 mm$H_2O$, respectively.

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Analysis on Ventilation Performance of Natural Ventilation Systems in Multi-Family Housing Using Blower Door Test (Blower Door Test를 이용한 공동주택 자연환기시스템의 환기성능 분석)

  • Kim, Min Seok;Auh, Jin Sun;Hong, Goopyo;Kim, Byungseon Sean
    • KIEAE Journal
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    • v.16 no.6
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    • pp.129-134
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    • 2016
  • Today, natural ventilation systems are widely applied in multi-family housing. However, studies using the wind data trend line of the blower door test are insufficient. Purpose: Through this study, we will propose a computational method about ventilation performance of natural ventilation systems by conducting blower door test. Method: First, we sealed the gaps between the main systems including the natural ventilation system and conducted the blower door test. Next, the natural ventilation system was opened, the blower door test was conducted, and the difference in air flow rate between when closed and when opened was checked. Blower door test was carried out with a pressure difference of 50 Pa. Result: Therefore, the ventilation performance of the natural ventilation system was checked by drawing a trend line using the data to calculate the air flow rate at 2 Pa of the natural ventilation equipment standard pressure difference.

A Study on Ventilation and Heat Transfer Coefficient of Passive Ventilation Skin (패시브환기외피의 통기성능 및 열관류율에 대한 연구)

  • Lee, Tae-Cheol;Son, Yu-Nam;Yoon, Seong-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.9
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    • pp.679-684
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    • 2012
  • This paper aims to evaluate performances of ventilation and insulation of 6types PVS(Passive ventilation skin) by numerical simulation. The results are as follows. 1) The result of Performance of ventilation by pressure difference, it was shown that the amount of ventilation changed bigger under 1Pa and amount of ventilation increased according to increase opening area (${\alpha}A$). Although same opening area of PVS, it can predict that pressure differences cause ventilation differences. 2) In case of same opening area of PVS, however, it was changed the amount of ventilation each types of PVS that is distinguished opening area by flow coefficient. 3) Dynamic U-value that represents performance of insulation PVS was similar change upper ${\alpha}A40\;cm^2/m^2$, great change in casse of 0.1 Pa pressure difference. In case of ${\alpha}A10\;cm^2/m^2$, it was changed bigger under 0.3 Pa pressure difference, ${\alpha}A20\;cm^2/m^2$ of PVS was changed under 0.2 Pa pressure difference.

A Research on the $CO_2$ Peak Point Control According to Ventilation Rate During Sleeping (취침 시 환기횟수에 따른 $CO_2$ 피크치 제어에 관한 연구)

  • Kim, Se-Hwan;Kim, Dong-Gyu;Park, Jong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.1
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    • pp.49-54
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    • 2009
  • Ventilation requirement of apartment was mandated according to building equipment standards in 2006. When ventilation unit was considering for indoor air quality maintenance, we needed energy saving and efficiency ventilation control methods. This study carried out experiment of ventilation rate 0.7 adequacy. When we lived in apartment, we assumed that sleeping time was long stayed time in unconsciousness. Experiments carried out ventilation rate 0, 0.1, 0.4 and 0.7 in environment chamber from 22 o'clock to 06 o'clock, the concentration of $CO_2$, temperature and humidity rate measured. Analyzing the results, conclusions are as follows. 1) When we sleep in bedroom, ventilation rate 0.4 meet the requirements of domestic legal standards. Conform fan of similarity law, ventilation rate 0.4 reduced power cost about 80% than 0.7. 2) In generally sleeping time 8 hours, peak point control reduced running time of ventilation unit about 43% than normal control.

A study on Forced Ventilation Rate for Bedroom Indoor Air Quality Improvement (침실 공기질 개선을 위한 강제 환기횟수에 관한 연구)

  • Kim, Dong-Gyu;Lee, Sung;Kim, Se-Hwan
    • KIEAE Journal
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    • v.9 no.1
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    • pp.85-90
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    • 2009
  • The indoor air quality is one of the most important issues of designing ventilation in high rise apartment buildings. This study suggested proper ventilation rate in the apartment bedroom where mechanical ventilation system has installed. Six university students(four male and two female) were participating in the experiment. Experiments were performed in environmental chamber. Experimental conditions were combinations from three ventilation rate 0, 0.4 and 0.7. Measurement items during 8 hours of experimental time were temperature, humidity, carbon dioxide concentrations and questionnaire surveyed aftrer sleeping. The concentration of Carbon Dioxide depending on ventilation rate in the chamber was analyzed for proper ventilation rate. The results of this paper can be summarized as follows. (1) When two persons experiment, 0.7 ventilation rate was in excess of 1000ppm. (2) When one person experiment, 0.7 and 0.4 ventilation rates were satisfied the criteria of IAQ. (3) It compared 0.4 with 0.7 in the ventilation rate, 0.4 ventilation rate could reduced about 80% of the power by fan similarity law.

Evaluation of Ventilation Rate and External Air Mixing Ratio in Semi-closed Loop Ventilation System of Pig House Considering Pressure Loss (압력손실을 고려한 양돈시설의 반폐회로 환기시스템의 환기량 및 혼합비율 평가)

  • Park You-me;Kim Rack-woo;Kim Jun-gyu
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.1
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    • pp.61-72
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    • 2023
  • The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

An Experimental Study on the Ventilation Performance to Enhance Removal Efficiency of Indoor Hamful Gases (실내 유해가스 제거효율 향상을 위한 환기성능에 관한 실험적 연구)

  • Ku, Jae-Hyun
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.117-124
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    • 2009
  • The objective of this research is to analyze the ventilation performance of mechanical ventilation systems to enhance removal efficiency of indoor hamful gases. The ventilation performance is evaluated using a step-down method based on ASTM Standard E741-83. The ventilation performance is evaluated as a function of the ventilation rate and supply/extract locations using a tracer gas ($CO_2$) technique. As a result, the $CO_2$ concentration as a function of time is decayed exponentially and the ventilation performance is found to increase with increased the ventilation rate. The ventilation performance of the second type ventilation system is better than that of the first type or the third type. The ventilation performance without human occupancy increases up to 55% and the ventilation performance with one person increases up to 25% at the supply air of 570Lpm comparing with a natural reduction after one hour in the test chamber. The ventilation performance is better than 15% comparing with natural decay at the supply of 570Lpm in an office room.

A study on the ventilation characteristics and design of transverse ventilation system for road tunnel (도로터널 횡류환기방식의 환기특성 및 시스템 설계 관한 연구)

  • Ryu, Ji-Oh;Kim, Hyo-Gyu
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.305-315
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    • 2018
  • In this study, the ventilation characteristics and the relationships between the required ventilation flow rate and the ventilation system flow rate was investigated by numerical method for the optimum design of the transverse ventilation and semi-transverse ventilation system in road tunnels. The following results were obtained. In supply exhaust transverse ventilation system, the system supply-exhaust air flow rate is theoretically equal to the difference between the required ventilation flow rate and natural ventilation flow rate. However, it is shown that it increases by about 10% in the analysis results. And, in the case of the longitudinal air flow rate is increased by installed jet fans, ventilation system air flow rate is reduced. However, as the longitudinal air flow rate increases, the concentration of pollutants in the tunnel decreases, so the exhaust effect of pollutants decreases, and the effect of reducing the system air flow rate is decreased. In case of semi-transverse with only air supply, ventilation system air flow rate is equal to required ventilation air flow rate when tunnel inlet velocity is negative, but results is shown it is increased within about 13.3%. Also, it was found that ventilation effect can not be expected even if the jet fans are increased when the tunnel inlet velocity is negative.

The Study on the Improvement of Ventilation Performance in the Soundproof Tunnel (방음터널의 자연환기성능 향상에 대한 연구)

  • Lee Kyung-Hee;Cho Sung-Woo;Choi Jeong-Min;Kim Kyung-hwan;Park Chang-Sub
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.10
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    • pp.922-929
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    • 2005
  • This paper compared ventilation performance between the sound roof tunnel with flat roof and the sound roof tunnel with gable roof. The ventilation rate of the sound roof tunnel is calculated by natural ventilation rate plus ventilation by vehicle. The roof type is divided by the shape of the roof and the ventilator location on the roof. The results between calculation and CFD on the ventilation rate are almost alike. The ventilation rate on the flat roof is $558.4\;m^3/s$ with mid-ventilator and $496.8\;m^3/s$ with left-right ventilator. The ventilation rate on the gable roof is $653.2\;m^3/s$ with mid-ventilator and $611.6\;m^3/s$ with left-right ventilator. The ventilation rate of soundproof with gable roof is higher than that with flat roof. The ventilation rate and with mid-ventilator is higher than that with left-right ventilator the soundproof roof. Therefore, the ventilation performance of soundproof roof depends on the roof shape and ventilator location on the roof.

Effective Local Exhaust Ventilation on Cooking Fumes of Seasoned Meats

  • Lee Byeong Kyu;Ellenbecker Michael J.
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.2 no.1
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    • pp.49-56
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    • 1998
  • This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.

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