• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.2
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• pp.85-95
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• 2019

The internal environment in pig house is closely related to the animal productivity. In addition, it is important to consider a working environment inside the pig house due to high gas and dust concentrations. The poor working environment inside the pig house can cause health problems including respiratory diseases. To analyze the working environment, it is important to evaluate the ventilation efficiency to effectively remove harmful gases and dust. The purpose of this study is to develop a 3D CFD model to analyze the working environment in the pig house. CFD model was validated by comparing air temperature distributions between CFD computed and field measured data. The average air flow rate at the pig height was 40.1 % lower than the working height when incoming air was concentrated on upper layer by the installed ventilation system on the experimental pig house. Using the validated CFD model, the regional ventilation efficiency was computed by the TGD(tracer gas decay) method at the pig and working heights. There was a difference of ventilation efficiency on 14 % between the air stagnated section and the rest sections. Stagnated gas concentration can be effected by animal and human health.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.160-165
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• 2005

Schools have significant and serious indoor environmental health problem, of which indoor air quality (IAQ) in school building may affect the health of the students and indirectly affect learning performance. Schools are of special concern when regarding indoor exposure to air pollutants, because students are particularly sensitive to pollutants and spend a significant amount of time in that environment. Therefore researches for improvement of indoor air quality have been developed such as installation of air cleaning device, ventilation system, titanium dioxide(TiO2) coating and so on. However, it is difficult to evaluate the magnitude of improvement of indoor air quality in field study because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. In this study, evaluation of reduction of formaldehyde emission rate in school indoor environments by far-Infrared ray coating material was carried out using mass balance model in indoor environment. we proposed the evaluation method of magnitude of improvement in indoor air quality, considering outdoor level and ventilation. Since simple indoor concentration measurements could not properly evaluate the indoor air quality, outdoor level and ventilation should be considered when evaluate the indoor air quality.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.2
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• pp.83-88
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• 2005

This study investigates the air leakage and heat transfer characteristics of a commercially available rotary-type air-to-air heat exchanger with a fiber polyester matrix. Crossover leakage between the exhaust and supply air is measured using a tracer gas method for various ventilation rates and rotational speeds of the wheel. A correlation equation for the leakage is obtained by summing up pressure leakage and carryover leakage. The pressure leakage is observed to be a function of ventilation rate only, and the carryover leakage is found to be a linear function of wheel speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiency by taking into account the leakage ratio. The heat recovery efficiency decreases, as the ventilation rate increases. As the wheel speed increases, however, the efficiency increases initially but reaches a constant value for the speeds over 10rpm.

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.171-178
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• 2019

In this paper, we proposed a plan for a indoor air quality management in elderly care hospital by measuring the indoor air quality level of elderly care hospital and conducting a survey the workers' awareness of indoor air quality. The measurement items were Temperature, Humidity, CO2, CO, PM10, VOC and were taken on April 26, 2019. The survey found that the lower the satisfaction level with indoor air quality, the better outdoor air quality and odor items were analyzed to be the lowest among the indoor environmental factors. When the satisfaction level of indoor air quality is high, the satisfaction level of indoor environment factor is high. The result of the multiple response analysis was "lack of ventilation" and the regression analysis was the lower the "relevance of indoor air quality" category. To provide the best indoor air quality environment for elderly care hospital workers the installation of additional ventilation equipment to remove odors, the increase in the number of natural ventilation and the designation of regular ventilation personnel will be necessary. By establishing such a plan, it is possible to provide indoor air quality environment to provide the best services for elderly care hospital workers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.12
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• pp.867-872
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• 2010

Numerical analysis has been conducted to investigate the fluid flow and fume mixing ratio characteristics of scattering fume in a push-pull ventilation system and optimally improve the flow patterns of scattering fume in the existing ventilation system. This ventilation system has been simulated by using commercial CFD code. In the case of the existing system, although the air is sprayed from air-curtain to prevent the fume from being scattered in upper hood, the improved air supply hood can remove the fume from the wide area in the high pressure. It is verified that the deeper plating storage is more advantageous. Also, by installing the shied around the plating storage, the scattering of the fume to the atmosphere was prevented effectively by surrounding flux.

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.19-26
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• 2016

Modern people spend much time at indoor space. So, People want to make better indoor air condition. But the facade of building is made of glass to be seen urbanely, the effect of solar radiation makes indoor environment worse. This study designs an open space affected by solar radiation with 4-way cassette air-conditioner. Using numerical simulation, this paper investigates thermal comfort and ventilation performance with discharge angles $30^{\circ}$ and $45^{\circ}$. To study thermal comfort, this paper studies distribution of velocity, temperature and effective draft temperature. Also, this paper introduces concept of air age to study ventilation performance. The flow influenced by solar radiation determines thermal comfort and ventilation performance in room space. This study shows that discharge angle of 45 degree has better thermal comfort and ventilation performance than that of 30 degree.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1337-1342
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• 2009

This test was progressed in the test house of KICT as sectional research of Center for Sustainable Housing. It included a ventilation rate of hybrid ventilation equipment, temperature, and gas test using the SF-6. The purpose of this test is to demonstrate the performance of viovent by estimating an outdoor air flow rate through viovent which the flimmer filter is installed and decide the leakage after operating the constant airflow fan within a house. First, the outdoor airflow rate through viovent measured $130\;m^3/h$ more than a legal required ventilation rate, $104\;m^3/h$. And then it sufficiently satisfy a legal standard, 0.7 air change/h. Secondly, the result of this test exposes that the leakage in the residence is about $20{\sim}25%$. Especially, the outdoor air flowing through the gate occupies 50% of the total leakage.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.190-199
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• 2018

Objectives: The purpose of this case study is to assess the current airflow and find the ideal ventilation conditions in tank reactors for minimizing the possibility of exposure respiratory dusts(size of $2.5{\mu}m$, $10{\mu}m$) when workers exchange catalysts in the tank reactors. Methods: A Numerical study was performed to determine ideal ventilation conditions, We considered two sizes of airborne respiratory particles($2.5{\mu}m$, $10{\mu}m$) at 12points from the bottom of tank reactor. We changed input & output ventilation conditions and analyzed the particle motion in the tank reactor. The star-ccm+, computational fluid dynamics tool was used to predict air & particle flow patterns in the tank reactor and a numerical simulation was achieved by applying the realized ${\kappa}-{\varepsilon}$ turbulence model and the Lagrangian particle tracking method. Results: From the results, the increase of recirculation air had a significant impact on removing dusts because they are removed by HEPA filter. To the contrary, Increasing the clean air quantity or changing the input position of clean air is not good for workers because it causes the exit of respiratory dusts through workers' entrance or cause it to remail suspended in the air in the workplace tank.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.6
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• pp.409-415
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• 2008

Recently, Indoor air quality (IAQ) is one of the most important problem in our daily life of modern societies. Mechanical ventilation system is being recommended as an effective method to improve IAQ in apartment houses. And then, in Korea, building industry should install ventilation system in apartment house by the building construction code. In this study, to improve IAQ caused by microbial and chemical contaminant such as bacteria and TVOC, three types of mechanical ventilation system of apartment house including HRV were simulated by multizone modeling. Simulation results suggest an appropriate and economical renovation method of apartment house ventilation system for reducing indoor air contamination.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.9
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• pp.506-515
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• 2013

The PFT (PerFluorocarbon Tracergas Technique) is of advantage to field surveys for evaluating the ventilation condition, due to its simplicity and convenience. On the other hand, it requires researchers to make some additional considerations that include uncertainties, such as the substance concentration distribution in indoor air, representativeness of a sampler, deviation of emission sources, and analysis error. In this study, the PFT and $CO_2$ tracer gas methods were applied simultaneously, to evaluate the accuracy of PFT on six ventilation conditions in the three-storied detached house. The air exchange and the outdoor air introduction a between and into zones were measured. As the results, deviations of PFT concentration distributions were observed at a sufficiently low level for an accurate determination for a house where the interior height was large, and there were relatively many partition walls. However, when a uniform airflow appeared in the indoor air, it was also validated that the indoor air would be exhausted without sufficient mixing, and consequently the measurement error of the PFT would be large.