• Journal of Animal Environmental Science
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• v.16 no.1
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• pp.41-50
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• 2010

The goal of this study was to develop a suitable ventilation system for high-rise hog building (HRHB) for growing-fattening with combined slatted floor pen in second story and in situ manure management system in Korea. The HRHB was constructed as 29m long, 9m wide and 7.6m high for outer dimension with an indoor height of 3.1m and 2.4 for lower and upper floor, respectively. Ventilation systems for each treatment were installed in separated rooms of HRHB. The ventilation types installed in each room were following 3 types: ventilation type 1 (V1), where air was pulled through a circular duct inlet and exhausted by fans; ventilation type 2 (V2), where air was pulled through eave inlet (side ceiling inlet) and exhausted by fans; and ventilation type 3 (V3), where air was pulled through baffled ceiling inlet and exhausted by fans. For each ventilation system, investigated air velocity under minimum, medium and maximum ventilation ratio and air flow pattern inside. The results were as follows; For air flow pattern from top to bottom, V1 showed a homogeneous vertical type, V2 showed a bilateral symmetry type and V3 showed an vertical umbrella type. Under minimum ventilation ratio, air velocity in upper floor (80cm above the slated floor) was similar for V1, V2, and V3. Under maximum ventilation ratio, air velocity in upper floor was undeviating for V1 (0.10~0.26m/s) and varied for V2 (0.12~0.63m/s) while those for V3 was relatively slow and less varied (0.07~0.15m/s). In conclusion, Duct inlet type (V1) can be applied to the development of a new HRHB with additional evaluations such as field test hog feeding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1600-1604
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• 2015

As modern houses are constructed with high-density and high-insulation, there is benefit to reduce energy consumption, but there are many side effects raised from polluted air. To solve the problem, a ventilation system is used to improve a indoor air quality. In this research, we experimentally estimate ventilation performance of HRV(heat recovery ventilator) with heat-pipe according to working fluid filling quantity and ventilation. Heat-pipe used in this study was designated separately to be applied to a ventilation system. The working fluid was R22, which was filled from 40 to 55 (%vol.) by 5(%vol.). Ventilation based on the front velocity was measured from 0.3 m/s to 1.5 m/s by 0.3 m/s intervals. Refrigerant filling quantity with the highest efficiency was found to depend on the ventilation. From this study the optimal refrigerant filling quantity in accordance with the ventilation of the detachable heat pipes was found experimentally.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.21-33
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• 2015

Recently, the Korean government announced a new development plan for a large-scale greenhouse complex in reclaimed lands. Wind environments of reclaimed land are entirely different from those of inland. Many standard books for ventilation design didn't include qualitative standard for natural ventilation. In this study, natural ventilation rates were analyzed to suggest standard for ventilation design of venlo type greenhouse built on reclaimed land. CFD (Computational Fluid Dynamics) simulation models were designed according to the number of spans, wind conditions and vent openings. The wind profile at a reclaimed land was designed using ESDU (Engineering Sciences Data Unit) code. Using the designed CFD simulation model, ventilation rates were computed using mass flow rate and tracer gas decay method. Additionally computed natural ventilation rates were evaluated by comparing with ventilation requirements. As a result of this study, ventilation rates were decreased with increasing of the number of spans. Ventilation rates were linearly increased with increasing of wind speed. When the wind speed was $1.0\;m{\cdot}s^{-1}$, only side vent was open and wind direction was $45^{\circ}$, homogeneity of ventilation rate at 0~1 m height is the worst. Finally, chart for computing natural ventilation rate was suggested. The chart was expected to be used for establishing standard of ventilation design.

• KIEAE Journal
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• v.11 no.6
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• pp.37-42
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• 2011

This Paper aims for analyzing the effect of opening types on wind-driven ventilation performance in basement parking lots of apartment. The scale model of basement parking lot was made, wind tunnel tests conducted. Wind pressure of three opening types was measured, wind pressure coefficient calculated. As the result, it showed that the air flow pattern of stack type opening was strongly changed by wind direction, but it was almost not at scuttle vent type. But, as for the difference of wind pressure coefficient, stack type opening was more than the other two types.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1197-1203
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• 2004

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

• 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.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.502-507
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• 2009

Trend of mechanical ventilation system applied to apartment house is introduced and feasibility study on installation of the individual room control ventilation as energy-saving method is carried out through field experiment. While initial cost of installation for the individual room control ventilation increases, the running cost is lower than the individual household control ventilation due to automatic flow rate control and reduction of fan power, and the management cost also decreases due to extension of use life of components. As the results of field experiment on $115m^2$-type apartment house, the individual room control ventilation could save the amount of 1,459.5Wh/day when compared with the individual room control ventilation

• Explosives and Blasting
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• v.24 no.2
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• pp.9-22
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• 2006

In general, tunnel construction except for special cases such as very short tunnels must require an artificial ventilation system. Especially, it is efficient for long tunnels to use the combination of a proper ventilation system according to the progress of the excavation. Neung-Dong Tunnel of which length is 4,580m has been originally designed as using ventilation system of blower and exhaust mixture types. Since it has been expected to result in some problems, its design Is analyzed to find the way to improve ventilation system by estimating the amount of required fresh air, considering various ventilation mixture types, ventilation's fluidity analysis and contaminant's distribution by numerical analysis. Economical efficiency for each type is also reviewed to determine the best ventilation system.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.385-391
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• 2000

An analysis of the heat transfer in a PDP ventilation chamber has been conducted to investigate the required heat curve and temperature uniformity of the panels. Firstly, experiment in a test chamber has been carried out and compared with the unsteady 3D numerical simulation. Reasonable agreement was found, which suggested that the employed numerical model had its credibility in an actual PDP ventilation process. On this ground, tact-type heating/cooling system was analyzed. The panel temperature was more uniform in the $40^{\circ}C$ tact-type system than in the $80^{\circ}C$ one. Comparison of full simulation of a cart and simplified simulation of one panel shows the panel pitch, which is closely related to a production rate, can be also predicted.