• 한국음향학회지
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• 제32권1호
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• pp.43-55
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• 2013

최근 창호의 창틀에 폐열회수장치를 삽입한 일체형 환기장치인 일명 "창호일체형 폐열회수 환기장치"를 개발됨으로써 창문을 열지 않고도 에너지 손실을 최소화하면서 실내외 공기를 교환할 수 있게 되었다. 그러나 이 장치의 작동시 기계소음과 공력소음이 발생하여 실제 주거시설에 적합하지 않은 면이 있다. 따라서 본 연구에서는 창호일체형 환기장치의 소음을 설치상태와 무향실에서 측정하고 소음의 발생 원인과 소음전달 취약부분을 분석하였다. 또한, 창호일체형 환기장치내의 차음재와 흡음재를 설치하여 소음을 제어하기 위한 대안을 제시하였다. 연구결과, 환기장치의 소음원은 블로워로 나타났으며 소음의 주된 누출 원인은 환기장치 구조체의 낮은 차음성능 때문이었음을 알 수 있었다. 또한 이를 제어하기 위하여 장치 내부에 고무시트 등의 차음재를 설치한 결과 폐열회수환기장치의 소음기준인 40 dBA 이하를 만족함을 알 수 있었다.

• 한국환경보건학회지
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• 제47권4호
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• pp.330-338
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• 2021

Background: This study was conducted to provide background information for the proper management of radon contamination in apartments using mechanical ventilation facilities in residential environments. Objectives: To this end, this study compared and evaluated changes in radon concentrations based on different operating intensities of mechanical ventilation with or without natural ventilation. Methods: For the continuous measurement of radon concentrations, an RAD7 instrument was installed in four apartments equipped with a ventilation system. The measurements were done for comparison of ventilation types and different ventilation intensities ("high", "middle", "low"). Results: The results confirmed that both mechanical and natural ventilation sufficiently reduced the radon concentration in the apartments. In particular, mechanical ventilation at "high" intensity was the most effective. Natural ventilation combined with mechanical ventilation and then natural ventilation alone were the second and the third most effective, respectively. Conclusions: When using ventilation to reduce indoor radon concentrations, it is most effective to operate mechanical ventilation ("high") or natural ventilation and mechanical ventilation at the same time. In cases where mechanical ventilation is available alone, it is recommended to operate it at a minimum of "middle" intensity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.737-740
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• 2004

The interior noise reduction of construction equipment is concerned for improving the driver comfort in this study. From the baseline test, the exhaust noise gives a big contribution to the interior noise of construction equipment. And the detail noise contribution analysis of the exhaust system, the tail pipe, which is for ventilation an engine room hot air to outside, amplify the exhaust noise around operating engine RPM associated with tail pipe structural and cavity resonances. To remove the noise amplifying effects, the tail pipe has to be shorted its length. Even the noise can be attenuated the ventilation flux when using the redesigned tail pipe is reduced than the original one. Thus, a shape change of the tail pipe is additionally needed for increasing the ventilation flux and attenuating the exhaust noise using CFD technique. The CFD results of the tail pipe give a meaning full information what obstructs the ventilation flex in the current design and how changes the tail pipe.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.95-100
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• 2007

The traction motor for High Speed Train is being required reliability and stability for high-speed operation. And also required low noise level, high performance, compact size owing to the space and weight limitation for attaching to train, etc. As a result of requiring the low noise level and high power capacity, it is adopted forced-air-ventilation insead of self-ventilation that is generally used on electric multiple unit. Traction motor is cooled by cooling air through the air-ventilation hole. When the traction motor is operated with forced-air-ventilation, there is some abnormal noise in the specific RPM. This paper is dealing with the method to reduce the resonance phenomena by adopting the rotor blade.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.201-209
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• 2001

Some passenger cars with sunroofs open at tilted positions experience reverse flows into cabin rooms and wind noises much louder compared to other cars. In this study, flows around open sunroofs are numerically studied with the variations of body leakage. The effects of body leakage on ventilation and wind noise of a sun roof are examined, in particular. Furthermore, flow visualization, pressure, and noise measured from wind tunnel and road tests are presented. The results show that too small body leakage results in poor performance of ventilation and generates high wind noise around a sunroof. It is therefore very important to secure an adequate body leakage from the early design stage to achieve better performance of a sunroof as well as passengers' comfort related to HVAC(Heating, Ventilation, and Airconditioning).

• 토지주택연구
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• 제13권3호
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• pp.107-113
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• 2022

건축물의 에너지소비를 줄이기 위해 건물의 기밀도가 지속적으로 향상되고 있으며, 이로 인해 건물 내부의 평균적인 상대습도가 높아지고 있다. 평균 상대습도가 높아짐에 따라 단열 취약부 및 습기발생 행위 시 결로가 발생하며, 습기제어를 위하여 기계 환기장치의 중요성이 향상되고 있다. 그러나, 기계환기장치는 추가적인 에너지 소비 및 소음 발생으로 재실자의 불쾌감을 유발하기 때문에, 서로 상충되는 기준에 대한 적절한 환기전략 선정이 필요하다. 본 연구에서는 공동주택 내 기계환기장치의 환기성능, 에너지 소비량, 소음도를 측정하여, 서로 상충하는 운영기준 중 우선순위에 있는 환기전략을 찾기위해 다기준 의사결정기법인 TOPSIS를 이용하였다. 또한, 재실자의 환기장치 운영기준 선호도에 따라 달라지는 적절 환기전략을 도출하였으며, 향후 AI 기술을 활용한 재실자 맞춤 환기전략 제시가 가능할 것으로 사료된다.

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.191-198
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• 2015

Noise propagated through the ventilation openings of enclosures is actively controlled using an FIR filter. The enclosures considered in this paper are used for isolating noise due to machinery. This method is of limited use because of the ventilation openings through which most of noise is propagated. Feedforward control strategy is incorporated to minimize the acoustic power propagated through the openings. For the real-time implementation, although it is numerical study, the controller is implemented using an FIR filter. The acoustic transfer functions of the pressure on the openings of the enclosure to the primary source and to the secondary source are numerically calculated using the boundary element method. The performance analysis of the active control is conducted with the time-domain simulation using Matlab Simulink.

• 수산해양교육연구
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• 제26권6호
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• pp.1373-1379
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• 2014

The purpose of this research is to evaluate the performance of the Ventilation hood and to make better oil collection for improvement. In order to complete the purpose, the research range has limited a kitchen cooking utensil used in preparing food in vessels. Assessment was carried out with reference(ASTM F1704-09) to the specification. Evaluation items of ventilation hood were flow visualization, oil collection rate and noise levels. When filter angle was 40 degrees, oil collection rate was increased by 9%.

• 설비공학논문집
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• 제29권4호
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• pp.175-184
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• 2017

With the improvement of living standards, the ventilation for the mitigation of indoor or outdoor air-pollution problems has recently attracted a lot of attention. Consequently, the ventilation for the supply of outdoor fresh air into a room is treated as an important building-design factor. The ventilation is generally divided into the forced and natural types; here, the former can control the ventilation rate by using mechanical devices, but it has the disadvantages of the equipment costs, maintenance costs, and noise generation, while the latter is applied to most workshops due to the absence of noise and the low installation and maintenance costs. In this experimental study, the ventilation performance of a typical rotating-type natural ventilator, which is called a "wind turbine," was investigated with the outdoor-wind velocity and the indoor/outdoor-temperature difference. From the experiment results, it was confirmed that the temperature difference of $10^{\circ}C$ corresponds to the ventilation driving force with an outdoor-wind velocity of 1.0 m/s. Additionally, the intake-opening area of a building also exerts a great effect on the ventilation rates.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.123-128
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• 2002

Over the range(OTR) has been applied for cooking and ventilation functions especially in northern Amarica. Because flow rate and operating rpm of the double sided sirocco fan for ventilation are much higher and than the microwave oven system, the major noise source is the sirocco fm. Recently, the quiet fan development is one of very important issues for amenity. In this study, the noise source identification using multi-microphone array system was carefully carried out and numerical simulations for understanding the aerodynamic and aeroacoustic of the fan were peformed. The sound level of tonal noise is predicted with a good accuracy but that of the broadband shows some discrepancy. In order to reduce the broadband noise, the inlet region of sirocco fan have to be modified that the secondary flow should be suppressed. Based on these results, new low noise fan and OTR is now developing.