• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.21 no.3
• /
• pp.193-200
• /
• 2009

The ventilation system of apartments can be divided by supply and exhaust fan, supply fan and exhaust free and supply free and exhaust fan. Recently, the individual ventilation system and central ventilation system which is combined cooling system with duct system are applied to apartment ventilation system. The airflow pattern is affected by location of supply unit and exhaust unit in indoor. This study is to investigate the proper distance between supply unit and exhaust unit using CFD. As a result of this study, the proper distance between supply unit and exhaust unit could be suggested at the interval of 3 m in supply and exhaust fan system and 2.5 m in supply fan and exhaust free.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.10
• /
• pp.982-992
• /
• 2001

In this paper, the performance of ventilation equipments in enclosed parking garages were investigated for several air distribution systems by numerical method. Air change effectiveness of the non-mixing system was 0.42. It meant that more supply air as much as the design supply air was needed to maintain good indoor air quality. In the high speed nozzle ventilating system which is most expensive one, air change effectiveness was 0.54. Therefore this system satisfied to ventilation design. In the jet fan ventilating systems, air change effectiveness for jet fan ventilating system-A with 18 jet fans and jet fan ventilating system-B with 6 jet fans in circulation mixing arrangement were 0.565 and 0.42 respectively. Jet fan ventilating system-C with 6 jet fans in transport mixing arrangement was 0.535. Jet fan ventilating system-A and jet fan ventilating system-C met the ventilation design. But velocity in jet fan ventilating system-A was over 2.0m/s which is inappropriate in human comfort. Therefore this system is not proper to ventilation. Jet fan ventilating system-C was the optimum one for enclosed parking garages among 5 systems examined in this paper.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2002.11a
• /
• pp.321-326
• /
• 2002

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.1 no.1
• /
• pp.1-7
• /
• 1997

Experimental study was carried out to investigate the interaction effect between spray fan formed by gas/liquid swirl injector. Test variables were supply pressure and injector distance. Water and air were the simulant for the experiment. For water supply only; Collected water mass was concentrated at the lower part of the two spray fan, but this effect was reduced with increasing supply pressure. Both air and water supply1; Collected water mass was again concentrated at the lower part of the impingement point, but this effect was reduced when air/water supply pressure ratio was increased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.16 no.2
• /
• pp.184-193
• /
• 2004

The purpose of this study is to evaluate the performance of various control strategies in commercial buildings which have been operated by the variable air volume (VAV) system. Two buildings in Seoul were chosen for the field study. The one (D building) combined by LonWorks has the constant airflow of supply fan and the proportional control of VAV units (damper type). The other (S building) combined by DDC has the PI control mode of the supply fan and the floating control of VAV units (venturi type). In estimating thermal comfort and energy performance through control modes of PI, PID, and CAV in the supply fan, we could identify several energy efficient operating control strategies for the VAV system.

• Journal of the Korean housing association
• /
• v.15 no.5
• /
• pp.77-84
• /
• 2004

The mock-ups of ventilation system, which has been widely adopted for the bathroom with the area of 100 $m^2$ apartment housing, were established and tested to design mechanical ventilation for apartment housing bathroom where air supply exhaust are relatively important. These ventilation mock-ups were capable of controlling intake and exhaust, which has the size of supply openings as 40cm${\times}$1cm, 40cm${\times}$3cm, 40cm${\times}$5cm. They were established at five locations, spaced 40cm from each other at a height of 25cm from the floor. The exhaust fans were located at four corners and center of the ceiling. The results this ventilation effect measurement by different condition are showing that when the size of air supply is bigger and the location is lower, the effect of ventilation was relatively higher. In addition, as the distance between exhaust fan and air supply was farther, the ventilation effect were getting highly efficient.

• Journal of the Korean housing association
• /
• v.12 no.3
• /
• pp.141-148
• /
• 2001

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$\textrm{m}^2$, were made and installed in a laboratory. These ventilation mock-ups were available for control of air supply and exhaust, and the sizes of supply openings were 40cm${\times}$1cm, 40cm${\times}$3cm, and 40cm${\times}$5cm. They were installed at five positions, spaced 45cm at a height of 5cm from the floor. The exhaust fan was designed for its operating voltage to be set to five steps(100V, 130V, 150V, 180V and 220V) in order to control its air flow rates. When the size and position of each supply opening were changed with the wind velocity of the exhaust fan set to the step 5, the ventilation rates were measured and analyzed by the concentration decay method of tracer gas method, in order to present an efficient mechanical ventilation system. The results of the study revealed that the ventilations rates would increase in the presence of supply openings, compared to the absence of supply openings, and that the larger the size of the supply opening, the more the ventilation rates. Therefore, it was found necessary to take air supply into consideration.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.15 no.4
• /
• pp.39-45
• /
• 2019

The operational conditions such as cooling tower water pump flow rate, cooling tower fan flow rate, and chiller capacity in heat source equipment, and supply air temperature and chilled water temperature in air conditioner are considered to study the effects on energy consumption for central cooling system by using TRNSYS program. As a result, the optimal values of supply air temperature and chilled water temperature for minimal total energy consumption are 12℃ and 8℃. And if maximum values of cooling tower water pump and fan flow rate is decreased from 100% to 40%, energy consumptions are increased 170MJ/day and 63.2MJ/day, respectively.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.6
• /
• pp.822-826
• /
• 2009

In case of engine room of ship, it uses type 2 ventilation system which supplies outside air forcibly by engine room ventilation fan, and naturally discharges air to outlet through low-pressed casing. The advantage of type 2 ventilation is that it makes inside with bi-pressure status to discharge contaminated materials to outside naturally. However, there is a phenomenon that pressure is greatly different between outside and inside due to huge amount of air supply by engine room ventilation fan. Therefore, we went aboard a container vessel which is on test run to analyze differential pressure with micronanometer by engine load and by combustion air supply method of engine. As a result, as engine load decreases (50, 75, 100%), the differential pressure between outside and inside tends to increase by 35% average, and the difference of pressure was 6.5 times maximum by combustion air supply method of engine.

• Journal of Advanced Marine Engineering and Technology
• /
• v.30 no.1
• /
• pp.50-57
• /
• 2006

This study describes to analyze the cooling load characteristics for a room air conditioner as a function of supply ventilation air when an air conditioner is running An experimental apparatus consists of a test room, a room air conditioner, a humidifier, an electrical heater a supply fan and a controller The reaching time to the inside setting temperature of the room air conditioner with is evaluated theoretically and experimentally in a conditioned space cooling loads such as supply ventilation air, lighting, occupancy and infiltration. In the conditions of cooling loads for the supply ventilation air of 9.5 L/s(0.98 ACH). lights. one Person, and infiltration, the reaching time to the inside setting temperature ($27\;^{\circ}C$ dry-bulb) increases up to $35\%$ more than for no supply ventilation air condition. Theoretical modelling of the reaching time shows good agreement with experimental results.