• Journal of Advanced Marine Engineering and Technology
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• v.30 no.2
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• pp.260-266
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• 2006

A tracer gas technique based on ASTM Standard E741-83 was used to measure ventilation performances in a model chamber ($0.84m{\times}0.68m{\times}0.7m$) with an exhaust fan and a supply fan. Experiments were performed for the ventilation effectiveness on three types of mechanical ventilation systems. For all cases. higher ventilation effectiveness was found in the type to ventilation system due to shorter residual time of air compared to type 1 and type 3.

• 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.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.211-218
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• 2021

BACKGROUND: Fine particulate matter (PM_2.5) is produced by chemical reactions between various precursors. PM_2.5 has been found to create greater human risk than particulate matter (PM₁₀), with diameters that are generally 10 micrometers and smaller. Ammonia (NH₃) and nitrogen oxides (NOx) are the sources of secondary generation of PM_2.5. These substances generate PM_2.5 through some chemical reactions in the atmosphere. Through chemical reactions in the atmosphere, NH₃ generates PM_2.5. It is the causative agent of PM_2.5. In 2017 the annual ammonia emission recorded from the agricultural sector was 244,335 tons, which accounted for about 79.3% of the total ammonia emission in Korea in that year. To address this issue, the agricultural sector announced the inclusion of reducing fine particulate matter and ammonia emissions by 30% in its targets for the year 2022. This may be achieved through analyses of its emission characteristics by monitoring the PM_2.5 and NH₃. METHODS AND RESULTS: In this study, the PM_2.5 concentration was measured real-time (every 1 hour) by using beta radiation from the particle dust measuring device (Spirant BAM). NH₃ concentration was analyzed real-time by Cavity Ring-Down Spectroscopy (CRDS). The concentrations of ozone (O₃) and nitrogen dioxide (NO₂) were continuously measured and analyzed for the masses collected on filter papers by ultraviolet photometry and chemiluminescence. CONCLUSION: This study established air pollutant monitoring system in agricultural areas to analyze the NH₃ emission characteristics. The amount of PM_2.5 and NH₃ emission in agriculture was measured. Scientific evidence in agricultural areas was obtained by identifying the emission concentration and characteristics per season (monthly) and per hour.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.12
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• pp.633-638
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• 2015

This study evaluates the capacity of night purging in office buildings to reduce the cooling load. RTS-SAREK is used to estimate the performance of night purging on the steady state. To overcome steady state RTS program limitations, we added unsteady heat transfer equations. When the ACH (Air Change per Hour) increases, the wall temperature decreases in both the steady and unsteady states. The unsteady heat transfer rate is different from the steady transfer rate, which validates the unsteady calculation. When ACH is low, the heat transfer rate increases continuously with time. When ACH becomes higher, the heat transfer rate increases and decreases with time. When ACH is quite high, there exists a large difference in the heat transfer rate between the steady and unsteady calculations, which emphasizes the importance of the unsteady calculation.

• KIEAE Journal
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• v.13 no.3
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• pp.79-89
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• 2013

The purpose of this study is to evaluate the airtightness performance of New Han-ok and to supply fundamental data for standards establishment. Air leakage testings were accomplished by means of blower door test in 26 bedrooms of 16 Han-oks located in Jeonnam happy villages. Followings are results. 1) Air change per hour at 50 Pa(ACH50) is located on 8.42~78.38. 2) No correlation between ACH50 and volumes, floor area, above grade surface area. 3) The more wood structural elements are exposed, attached spaces, wooden sliding and casement windows, the less airtightness performance. 4) An Airtightness with ACH50/20(NL, Normalized leakage) is located on 0.42~3.92 and building leakage class following F(4%), G(11%, sufficiently leaky, No need mechanical ventilation), H(4%, Need of cost-effective tightening), I(31%), J(50%) by a single-story house the normalized leakage of ASHRAE.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.154-159
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• 2005

The markers for Environmental Tobacco Smoke(ETS) a.e necessary to obtain, to interpretate and to provide the data of quantitative exposure assessment. The purpose of this research is to evaluate Indoor environment using the concentration of ETS and the correlations between markers(RSP, nicotine, 3-EP) and environmental conditions(smoking density, ventilation rate). The mean ACH(air change per hour) in smoking rooms showed non-compliance with ASHRAE standard value. The concentrations of RSP, 3-EP, nicotine showed log-normal distributions, and became different statistically depending on smoking condition(p<0.01). The geometric mean concentration of RSP in smoking room was 441.7 ${\mu}g/m^3$ that is far exceeded environmental standard(150 ${\mu}g/m^3$). The correlation coefficients between RSP and SI, 3-EP and SI, and Nicotine and SI were 0.67, 0.84, 0.74 respectively. The correlation coefficient between nicotine and 3-EP, Nicotine and RSP, and RSP and 3-EP were 0.76, 0.78, 0.57 respectively.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.43-49
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• 2003

ETS concentrations in the PC game rooms and factors affecting ETS concentrations were measured. Nicotine, 3-EP, respirable dust and UVPM were used as tracers for ETS. ETS concentrations are 2-3 times higher than those of other results. The concentration of ETS at the commercial district was higher than that of the residential district. The correlations between these tracers and SD/ ACH, a factor affecting to ETS concentration, were calculated. The correlation between 3-ethenylpyridine among tracers and SD/ACH was highest. The correlation between respirable dust and SD/ ACH was lowest. It was difficult to recommend respirable dust as a tracer of ETS.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.469-474
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• 2008

The objective of this study is to propose basic design guidelines for more effective air ventilation system in apartments. It is well known that ventilation depends on whether the room doors are open or closed as well as people's living patterns. This study considers 84 ㎡-sized apartment which has extended living room without balcony. Ventilation of bathroom and kitchen is not considered. The height of the building, external air pressure and air infiltration through the windows are also neglected. The regulation on indoor air quality made it mandatory that the air change per hour be more than 0.7. Four models are suggested to study the effect of open and closed doors. Models 1 and 3 are open door types and models 2 and 4 are closed door types. The open types have 50 mm hole near the top of the door to substitute exhaust outlet. The ventilation effectiveness was evaluated by 3-dimensional numerical simulation using finite volume method by a commercial software. This work compares air flow, temperature of air, age of air and the efficiency of ventilation of apartments with wooden doors of bedroom 1 and 2, which are open or closed.

• Land and Housing Review
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• v.13 no.2
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• pp.117-123
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• 2022

In this study, titanium dioxide photocatalyst was applied to the ventilation system to reduce particulate matter and nitrogen oxides (NOx), which are representative indoor harmful substances. A reaction device capable of installing an ultraviolet lamp was designed and manufactured so that the pollutant decomposition effect of the titanium dioxide photocatalyst identified through previous studies could be applied indoors. The reaction device was used on the indoor ventilation system and applied to the Mock-Up test. As a result of the Mock-up test, the NOx reduction performance according to the change in air volume once per hour and five times per hour was confirmed. As a result, it was confirmed that as the number of ventilation increases, the NOx reduction time decreases proportionally, and the reduction performance increases.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1207-1212
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• 2008

The purpose of this study is to evaluate the location of the outlets in the mechanical ventilation system installed in apartment. We performed the numerical analysis to estimate the ventilation effectiveness and the indoor $CO_2$ concentration considering the occupants and the condition with inlet and outlet in each room. From the numerical results, modified location of the outlets is about 10% high than designed one with respect to the ventilation effectiveness when the occupants are not considered. But designed location of inlet and outlet in living room and kitchen is better than modified one with respect to the reduction of $CO_2$ concentration in the living room and kitchen with occupants. In case of our model, Air change per hour (0.7) is not enough to sustain the acceptable criteria of $CO_2$ concentration (1000ppm) in the room with the occupants