• Title/Summary/Keyword: Indoor Pressure

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An Analysis on the Effect of Pressure System Installation on the Pipeline to Identify Pressurized Water and Self-inspection Ease in Apartment Building (아파트에 설치하는 옥내소화전 압력계 설치가 배관의 가압수 식별 및 자체점검 용이성 간의 영향 분석)

  • Son, Joo-Dal;Kong, Ha-Sung
    • Journal of the Korea Safety Management & Science
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    • v.22 no.1
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    • pp.33-44
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    • 2020
  • This study analyzed how the installation of a pressure gauge in the indoor fire hydrant of an apartment building affected identifying pressurized water in the pipe, making it easier to conduct internal inspection on the fire suppression system, and ensuring reliability of fire suppression. The following are the study's results: First, identifying pressurized water in the indoor firefighting pipe had a positive effect on the installation of a pressure gauge in the indoor fire hydrant. This implies that a higher level of identification of pressurized water in the indoor firefighting pipe had a positive impact on improving the installation and use of a pressure gauge in the indoor fire hydrant. Second, making it easier for the fire safety officer to inspect the fire suppression system had a positive effect on the installation of a pressure gauge in the indoor fire hydrant. This suggests that if it becomes easier for the apartment building's stakeholder to conduct internal inspection or the firefighting facility manager to carry out inspection on the fire suppression system, it would have a positive effect on the installation of a pressure gauge in the indoor fire hydrant. Finally, ensuring reliability in fire suppression had a positive effect on the installation of a pressure gauge in the indoor fire hydrant. This implies that if it becomes easier to identify pressurized water in the indoor firefighting pipe, for the fire safety officer to conduct internal inspection, or for the firefighting facility manager to carry out inspection in accordance with the fire suppression system's internal inspection requirements, it would increase reliability in fire suppression, making it more necessary to install a pressure gauge in the indoor fire hydrant.

The Impact of Double-Skin Façades on Indoor Airflow in Naturally Ventilated Tall Office Buildings

  • Yohan, Kim;Mahjoub M. Elnimeiri;Raymond J. Clark
    • International Journal of High-Rise Buildings
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    • v.12 no.2
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    • pp.129-136
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    • 2023
  • Natural ventilation has proven to be an effective passive strategy in improving energy efficiency and providing healthy environments. However, such a strategy has not been commonly adopted to tall office buildings that traditionally rely on single-skin façades (SSFs), due to the high wind pressure that creates excessive air velocities and occupant discomfort at upper floors. Double-skin façades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as the fundamental components such as the additional skin and openings create a buffer to regulate the direct impact of wind pressure and the airflow around the buildings. This study investigates the impact of modified multi-story type DSFs on indoor airflow in a 60-story, 780-foot (238 m) naturally ventilated tall office building under isothermal conditions. Thus, the performance of wind effect related components was assessed based on the criteria (e.g., air velocity and airflow distribution), particularly with respect to opening size. Computational fluid dynamics (CFD) was utilized to simulate outdoor airflow around the tall office building, and indoor airflow at multiple heights in case of various DSF opening configurations. The simulation results indicate that the outer skin opening is the more influential parameter than the inner skin opening on the indoor airflow behavior. On the other hand, the variations of inner skin opening size help improve the indoor airflow with respect to the desired air velocity and airflow distribution. Despite some vortexes observed in the indoor spaces, cross ventilation can occur as positive pressure on the windward side and negative pressure on the other sides generate productive pressure differential. The results also demonstrate that DSFs with smaller openings suitably reduce not only the impact of wind pressure, but also the concentration of high air velocity near the windows on the windward side, compared to SSFs. Further insight on indoor airflow behaviors depending on DSF opening configurations leads to a better understanding of the DSF design strategies for effective natural ventilation in tall office buildings.

Pressure Analysis and Conceptual Design for Indoor Ballistic Test Range by Numerical Methods (수치해석기법을 이용한 실내시험장 압력특성해석 및 개념설계)

  • Jung, Hui-Young;Park, Kwan-Jin;Kim, Nam-Hyuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.1
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    • pp.55-62
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    • 2017
  • For evaluating a large caliber ammunition tests, indoor ballistic test range is required to reduce the noise and fragments occurring during the test. To ensure the reliability of the indoor ballistics test range design, we carried out the analysis of the indoor test range using the AUTODYNE hydrodynamic code before its construction. The 120 mm tank ammunition is adopted as a reference model and we analysed the characteristics of the pressure distribution at fire area, the structure design at impact area, the over-pressure applied to the tunnel, and the sabot stopper design. The results of the analysis were applied to the design of the indoor ballistic test range.

A Simulation Method for Considering the Outdoor Wind-Pressure in Calculation of Indoor Air-Flow in High-Rise Buildings (건물 내 공기유동 해석에 외부 바람이 미치는 영향의 분석)

  • Kim, Dae-Young;Song, Doo-Sam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.2
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    • pp.55-62
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    • 2016
  • The air flows in building caused by thermal buoyancy, known as the stack effect, have a pronounced influence on both the indoor environment (thermal environment, noise, draught and contaminant diffusion) and energy needs in high-rise buildings. Prior studies for airflow in high-rise buildings were focused on the degree of stack effect and countermeasures. The wind pressure was neglected during the calculation of the indoor airflow in high-rise buildings to clarify the effect of thermal buoyancy in previous studies. However, wind is an important driving force of indoor airflows in buildings with the stack effect. In this study, the effect of wind pressure on indoor airflow in high-rise building when the stack effect is dominant in winter was analyzed. In this paper, methods that involved considering the wind pressure in airflow network simulation were analyzed.

A Case Study on the Ventilation System of the General hospital (종합병원의 환기설비 사례 연구)

  • Jung, Jong-Rim
    • KIEAE Journal
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    • v.4 no.3
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    • pp.187-194
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    • 2004
  • In many other buildings, hospital is very important because of its function and purpose. A proper building service systems including heating, cooling, ventilation and plumbing systems is required in hospial. Besides, a special systems like medical gas, vacuum cleaning systems are required to prevent contamination as well as cure a patient in hospital. Ventilation is very important method to keep the indoor pressure and clean class. There are some specific rooms to consider clean class and indoor pressure in the general hospital. In this article, specific rooms were set to operating room, laboratory, ICU, isolation unit, and sterilizer room. In this case study, design factors of ventilation system, including air changes of OA and TA, indoor pressure, clean class, filter, and material of system, of specific rooms in hospital were proposed through a literature research and a design examples review.

A Study on Improvement of Discharge Pressure Measurement of Indoor Fire Hydrant System (옥내소화전설비의 방수압 측정 개선에 관한 연구)

  • Min, Se-Hong;Jeong, Sang-Ho
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.67-72
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    • 2012
  • Indoor fire hydrant facilities and sprinkler system applied to the initial fire suppression for buildings' interior fire are pivotal roles in extinguishing the fire in the early stage. The roof shapes of recent buildings combined with distinctive local culture and design are being constructed. Distinctive roof forms, i.e. gable roof buildings are planned and built, View point planning with the roof gardens also restricts measurement of the discharge pressure on the indoor fire hydrant, It is too narrow to gauge the water discharge pressure with deploying up to 5 water hoses. To resolve these problems improvement for the efficient management of indoor fire hydrant system and the effective early stage flame extinguishment is suggested.

Practical Algorithms for the Effective Operation of a $CO_2$ Air-conditioner (이산화탄소에어컨의 효율적인 운용을 위한 실용알고리즘)

  • Han, Do-Young;Park, Seung-Ho
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.435-440
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    • 2009
  • For the effective control of a $CO_2$ air-conditioning system, the system high-side pressure algorithm, the indoor temperature algorithm, and the outdoor fan algorithm were developed. The system high-side pressure algorithm was composed of the setpoint algorithm, the reset algorithm, and the electronic expansion valve control algorithm. The indoor temperature algorithm was composed of the compressor control algorithm and the indoor fan control algorithm. These algorithms were tested by using mathematical models developed from the previous study. Results from the setpoint step change test and the disturbance test showed good control performances. Therefore, algorithms developed in this study may practically used for the control of a $CO_2$ air-conditioning system.

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Effects of Heat Wave on Body Temperature and Blood Pressure in the Poor and Elderly

  • Kim, Young-Min;Kim, So-Yeon;Cheong, Hae-Kwan;Ahn, Byun-Gok;Choi, Kyu-Sik
    • Environmental Analysis Health and Toxicology
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    • v.27
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    • pp.13.1-13.10
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    • 2012
  • Objectives: We aimed to investigate the acute effects of heat stress on body temperature and blood pressure of elderly individuals living in poor housing conditions. Methods: Repeated measurements of the indoor temperature, relative humidity, body temperature, and blood pressure were conducted for 20 elderly individuals living in low-cost dosshouses in Seoul during hot summer days in 2010. Changes in the body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to variations in the indoor and outdoor temperature and humidity were analyzed using a repeated-measures ANOVA controlling for age, sex, alcohol, and smoking. Results: Average indoor and outdoor temperatures were $31.47^{\circ}C$ (standard deviation [SD], $0.97^{\circ}C$) and $28.15^{\circ}C$ (SD, $2.03^{\circ}C$), respectively. Body temperature increased by $0.21^{\circ}C$ (95% confidence interval [CI], 0.16 to $0.26^{\circ}C$) and $0.07^{\circ}C$ (95% CI, 0.04 to $0.10^{\circ}C$) with an increase in the indoor and outdoor temperature of $1^{\circ}C$. DBP decreased by 2.05 mmHg (95% CI, 0.05 to 4.05 mmHg), showing a statistical significance, as the indoor temperature increased by $1^{\circ}C$, while it increased by 0.20 mmHg (95% CI, -0.83 to 1.22 mmHg) as outdoor temperature increased by $1^{\circ}C$. SBP decreased by 1.75 mmHg (95% CI, -1.11 to 4.61 mmHg) and 0.35 mmHg (95% CI, -1.04 to 1.73 mmHg), as the indoor and outdoor temperature increased by $1^{\circ}C$, respectively. The effects of relative humidity on SBP and DBP were not statistically significant for both indoor and outdoor. Conclusions: The poor and elderly are directly exposed to heat waves, while their vital signs respond sensitively to increase in temperature. Careful adaptation strategies to climate change considering socioeconomic status are therefore necessary.

Study of the Indoor Noise Limit for Naval Vessels Considering the Satisfaction of the Crew (승조원의 만족도를 고려한 함정의 함내소음 기준 분석)

  • Han, Hyung-Suk;Park, Mi-Yoo;Cho, Heung-Gi
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.4
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    • pp.589-597
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    • 2010
  • The indoor noise of the naval vessel is very important considering hearing protection, improvement of working environment and easily communication between crews. When the environment of the naval vessel suffering from the noise is considered, it is very important to be quiet in the living area where the crews have a rest sufficiently. In addition, the noise of the working area should be reduced in order to increase working efficiency. Therefore, in this research, the satisfactions about the indoor noise are survey for crews working in a naval vessel. Through this survey, the relationship between the indoor noise and crew's satisfaction about it can be found. As a result, the limit of sound pressure level which almost all crew can be satisfied with the indoor noise about their living and working area is suggested base on the survey in this research.

Correlation Analysis of Parameters affecting Pressure Distributions in Vertical Shafts by Design of Experiments (실험계획법에 의한 수직샤프트내 압력분포에 영향을 미치는 인자간 상관관계 분석)

  • Han, Hwa-Taik;Shin, Chul-Yong
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.883-888
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    • 2008
  • Various effluents generated in cooking processes contribute a great deal to indoor air pollution among many other indoor pollutants such as dusts from outdoor and carbon dioxide from human body. Kitchen exhaust hoods are not believed to exhaust indoor contaminants properly in many cases, while generating too much noise. Instead of focusing on individual products of kitchen hoods, we should address the problem by attacking the ventilation system as a whole including vertical shafts and building air-tightness. In this study, it is intended to investigate the pressure distribution along the vertical shaft depending on various system parameters, such as shaft size, concurrent hood usage rate, roof fan, inlet pressure loss, and outdoor temperature. The maximum static pressure in the vertical shaft has been obtained using the method of design of experiments and analyzed by the analysis of variance. The results can be used for the design of kitchen exhaust systems by analyzing the pressure distributions in vertical shafts.

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