• Proceedings of the KSME Conference
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• 2000.11b
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• pp.520-525
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• 2000

This research is to analyze the ventilation performance of mechanical ventilation systems for indoor air quality control and management. A ventilation performance with supply sites is evaluated in a test model chamber and office room. A $CO_2$ gas as a tracer gas is used to measure the ventilation performance. The ventilation performance is found to increase with increased the ventilation rate. The ventilation performance is analysed with 55% at the supply air of 570 lpm and with 20% at the supply air of 100 lpm in a test chamber. The ventilation performance is better than 15% comparing with natural decay at the supply of 570 lpm in office room.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.11
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• pp.711-717
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• 2011

In this study, 5 types of PVS(Passive ventilation system) units are made and experimented its ventilation performance, thermal performance according to open rate and hole diameter of perforated aluminum plane. Results are as follows. 1) The ventilation performance increases approximately 50~70% according by the open rate of PVS increasing. Also, the ventilation performance increases about 2%~12% according by the hole diameter of PVS increasing. 2) In winter temperature/pressure condition(in : $20^{\circ}C$, out : $-2^{\circ}C/{\Delta}P$ : 0.2~5.0Pa) the temperature of inflow air decreases according by the open rate of PVS increasing. Heat gain performance decreases 10.1%, 25.6% when open rate increases 3) In the same condition, Heat gain performance decreases 18.3%, 18.8% according by the hole diameter of PVS increasing.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.31-37
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• 2012

This paper describes to analyze the ventilation performance of a room air conditioner for indoor comfort control. An experimental apparatus consists of a test room, the room air conditioner, a tracer gas measurement system, a supply fan and a controller. Ventilation performance as a function of human occupancy is evaluated with supply ventilation air using a tracer gas technique of CO2 gas in the test room. The ventilation performance is evaluated in a step-down method based on ASTM Standard E741-83 and is found to increase with increasing supply ventilation rate. The CO2 gas concentration is decayed rapidly without human occupancy. 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 570 lpm comparing with a natural reduction after one hour. A modeling for ventilation performance of a room air conditioner in a test room is presented using experimental datum.

• KIEAE Journal
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• v.12 no.1
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• pp.29-34
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• 2012

As a series of studies about natural ventilation driven by wind in basement parking lots of apartment, the influence of opening size and surrounding buildings on ventilation rate was analyzed. Natural ventilation in underground parking lots almost rely on wind than temperature difference. To investigate natural ventilation driven by wind, wind tunnel tests by using scale model and tracer gas method were conducted. $CO_2$-gas concentration was measured, natural ventilation rates were calculated. The experimental results showed that the natural ventilation rate is more reliable to wind direction and surrounding building than opening size and distance between buildings. It was verified that surrounding buildings play a principal role in increasing air flow rate by accelerating wind speed, and growing turbulence intensity. And it showed that ventilation performance is able to be increased by oblique wind to entrance ramp than head on wind in underground parking lots with surrounding buildings.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.4
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• pp.594-603
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• 2002

The characteristics of moisture ventilation in a dry room were studied numerically The effect of three important parameters: position of outlets, aspect ratio($\beta$) of horizontal plane and air exchange rate(N), was analyzed by using the scales of ventilation efficiency. The ventilation performance was evaluated by varying the aspect ratio and air exchange rate in the four types of outlet position. It was shown that the ventilation performance was improved by decreasing the aspect ratio in the longitudinal arrangement of outlet. The highest ventilation performance was determined when $\beta$ was 4 in the transverse arrangement of outlet. Regardless of the aspect ratio, the ceiling arrangement of outlet played more dominant effect on the ventilation efficiency than the floor arrangement. In every type and aspect ratio, the increase of air exchange rate to improve ventilation performance was appropriate up to N=60 /h.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.2
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• pp.112-121
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• 2006

To evaluate the performance of ventilation system properly, the correlations among the ventilation rate, indoor air-quality and cooling/heating load should be analysed. In this study, simulation tool to analyze the performance of ventilation system was developed. The simulation tool is based on the TRNSYS and some modules to calculate concentration of pollutants with the operation of ventilation system and to decide the signal of ventilation system were newly developed in this study. And these modules coupled with building load and heating/cooling simulation modules. To verify the validity of developed simulation tool, comparison study between simulation and field study were accomplished. As results, the simulation tool developed in this study can be used to predict the performance of ventilation system with accuracy.

• 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.

• 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.

• Journal of the Korean Solar Energy Society
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• v.25 no.2
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• pp.71-79
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• 2005

In this study, the ventilation performance of mechanical ventilation system in apartment House was analyzed through model test according to characteristics of air-vent. Then adequate interval of air-vent was suggested using computer simulation which will create comfort environment through improvement of ventilation performance in apartment house. The result of experiment with separation plate to prevent mixture of contaminated exhaust air with fresh supply air, the ventilation efficiency improved about 10%. The result of simulation with horizontal location of exterior air-vent, contaminated exhaust air is mixed regardless of interval variation. Consequently, mixture of the exhaust air can be prevented through locating the supply air vent on the top side and exhaust air vent on the lower side.