• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.5
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• pp.439-445
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• 2003

The purpose of this study is to suggest the improvement strategies for exhaust performance in composite kitchen hoods. The Exhaust only hood, the 2-way compensating hood and the 3-way compensating hood were selected, and the laboratory experiments were performed to compare the local exhaust efficiency and the indoor temperature distributions according to the variations of the hood type and supply/exhaust air velocity. The results of this study can be summarized as follows. The compensating hood has better performance than exhaust only hood in the aspect of local exhaust efficiency and temperature distribution. The 3-way compensating hood shows the best performance when the supply air velocity is about 2.7 m/s, and the 2-way compensating hood at the supply air velocity of 3.5 w/s. In the same exhaust rate condition, if the exhaust area of the hood is increased and therefore the exhaust velocity is lowered, the supply air velocity is also lowered to get the optimum performance. The optimum exhaust velocity range of the commercial kitchen hood which derived from this study is 0.48 ∼ 0.55 m/s.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.63-68
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• 2005

In the present paper, the study on the optimal horizontal air jet velocity of a range hood system has been studied by three dimensional numerical simulation. It has been shown that the air jet of a range flood system generates coanda effect confining the contaminated (high temperature) air in a certain region while the jet pushes out more contaminated air into a room as the jet velocity increases. Therefore, the optimal jet velocity has been determined by the combination of the two mechanism.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.489-494
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• 2016

There have been many cases when an air curtain installed in the apartment could not remove the gases well, such as carbon dioxide and particles like as smoke, oils, and vapors generated during cooking to disperse pollutants into the room. This study used a numerical analysis to show how the pollutant-removing performance of the range hood is changed when the air curtain is installed front of the kitchen table. The result of this study was that when the air amount supplied by an air curtain through the slot was about 50% of the exhaust amount, the capturing efficiency of the range hood for pollutants increased 90% more than without an air curtain. Even when the amount of supplied air was small, the capturing efficiency improved markedly with the use of an upward air curtain. In case that the air flow rate of the slot was greater than 60%, the capturing efficiency decreased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.4
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• pp.321-327
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• 2007

In an apartment house that is generally air-tight and well insulated, the combustion gas from cooking devices is the major source of air pollution in the kitchen. It spreads throughout the house affecting the overall Indoor all quality. In this study, the performance of the kitchen range hood which employs air induction and air curtain was investigated by numerical simulation. The results are compared with that of two other kitchen range hoods which are in general use. The two general types of range hoods considered in the present calculations are box and plate type range hoods. The former has a large capture space between the filter and suction duct, while the latter has little. It was found that the capture efficiency of the kitchen range hood with air induction and air curtain Is higher than that of the general types of range hoods by 20% approximately The reason may be because the air induction and the air curtain block the air stream escaping from the front and the side part of range hoods effectively and because an additional fan for air induction and air curtain increases suction flow rates.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.4
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• pp.333-340
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• 2005

Horizontal air-jet effect has been utilized in some air conditioning systems in order to control the contaminated air indoor. In the present study, the flow and heat transfer of the contaminated air from a range hood system has been investigated with or without horizontal air-jet effect when the hood fan is on or off. For the present numerical experiment, PAT Flow code has been used. From the present numerical simulations, it has been shown that the air jet of a range hood generates coanda effect confining the contaminated air in a certain region. Furthermore, the qualitative relation between the flow rate of the capture air jet and the distribution pattern of the contamination has been discussed.

• The KSFM Journal of Fluid Machinery
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• v.8 no.2 s.29
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• pp.9-15
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• 2005

This paper presents an experimental and numerical study on the overall performance and local flow characteristics of sirocco fan in a range hood. Measurement of overall performance for sirocco fans were conducted based on AMCA standard 210. The effects of flow blockages due to the motor inside the fan on the fan performance were investigated by experimentally and numerically and the results were compared with each other. The numerical and experimental results show the inlet flow blockage reduces the performance (ie. fan static pressure, design flow rate, maximum efficiency and free delivery flow rate) of fan. It is found that the blockage makes the flow field highly non-uniform through the blade and cause the efficiency decrement.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.9
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• pp.468-474
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• 2015

When oil is used for cooking in detached or apartment houses, large amounts of oil-mist, smoke, and particulate substances are generated and dispersed into the indoor-air environment. These pollutants diffuse into the surroundings and spread their odor while rising fast at a high temperature due to the heat energy from the gas range. Although the exhaust gas is discharged from the exhaust hood, which is installed on the top of a gas range to remove the diffuse pollutants, the exhaust conditions can vary greatly because they depend on the shape of the exhaust hood and the discharge rate. In this paper, the air that is required for the gas-exhaustion process is supplied by an air curtain that surrounds the kitchen hood, and the pollutant-capturing efficiency varies depending on the angle of the discharge grills; the pollutant-capturing efficiency was studied using a numerical-analysis method. The results indicate that the pollutant-capturing efficiency is not significantly changed by a change of the discharge-grill angle at a low air-discharge rate; however, at a high air-discharge rate, the efficiency value increases with an increase of the discharge-grill angle, whereby the best value occurs at 30 degrees and the efficiency decreases above this angle. Below 30 degrees, the effect of the discharge rate on the capturing efficiency is more than that of the discharge-grill angle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3363-3369
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• 2014

Recently, considerable effort has been made to maintain a pleasant and safe indoor environment in buildings. For this, the use of a ventilation system attached to a range hood in kitchens has prevailed. Accordingly, diversiform designs for range hoods have been used. Press molding is normally used for range hood construction for several reasons. On the other hand, its economic efficiency is low in the case of a small production work. Considerable research has been carried out to solve this problem and it is believed that it is useful to use the change core method to develop molds. This study designed the core of a mold using the change core method and a total of four processes were used in its manufacture. As a result, the press molds, which are needed for shorter production runs and whose form is changeable, were developed. In addition, after the measurements in three-dimensions, the specimen passed a test within a tolerance of ${\pm}2.00mm$.

• Journal of the Korean housing association
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• v.15 no.3
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• pp.101-108
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• 2004

To find more efficient exhaust effect, air curtain of upward or downward trend in gas table and left or right side of range hood were made. As result that film vapor from range hood lower part by digital camera, the air current change by moving existence and nonexistence of exhaust fan and direction of air curtain were known. Under all experiment condition, upward air curtain superior exhaust performance.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.572-577
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• 2004

This paper presents numerical study on the performance improvement of the sirocco fan in a range hood. The performance of sirocco fan means a higher flowrate, a higher static pressure and a lower required motor power in a fixed geometry constraint. Various impeller geometric parameters, such as blade profile, blade diameter, blade thickness profile and blade exit angle, were investigated by numerically and the results were compared with each other to know the effects on the performance. In this approach, the volute geometry were fixed with the original shape. The numerical results show that the blade profile with airfoil shape and small exit blade thickness increases the performance. The blade exit angle shows optimum angle within a varied range. The efficiency of the optimized exit angle was about $10\%$ higher than the base blade exit angle and the static pressure was about $28\%$ higher at the flow coefficient 0.22.