• 한국산업보건학회지
• /
• 제29권3호
• /
• pp.343-350
• /
• 2019

Objectives: This study aims to identify whether ventilation conditions and their effectiveness can be significantly improved in an experimental chamber by increasing the mixing factor (K-Factor). Methods: In a chamber with a volume of $1m^3$, air velocity was measured at six different points with four roof fans in the upper part of the chamber being operated in order. The impact of the ventilation conditions was analyzed when the flow rates were increasing and the first inlet of the chamber was either open or closed. Smoke patterns were also observed at four corner points where ventilation was limited. Kruskal Wallis and Mann-Whitney tests were performed to compare air velocities measured in the chamber. Results: The air velocities measured at only the third point increased significantly from $0.03{\pm}0.03m/s$ (door open) and $0.05{\pm}0.06m/s$ (door closed) with two fans, $0.08{\pm}0.08m/s$ with three fans, and $0.09{\pm}0.09m/s$ with four fans operating (p<0.05). However, air velocities at the four corner points did not significantly increase. Smoke patters also showed that the open inlet of the chamber had no effect on improvement of ventilation conditions and effectiveness. Conclusions: In this study, the air velocities at six points in the chamber did not significantly increase despite the increase in the mixing factor and flow rates of ventilation in the controlled environment. Therefore, the inflow of outdoor air throughout an open inlet and installation of a forced ventilation system can potentially increase the indoor air velocity and improve ventilation condition without an increase in the mixing factor.

• 화훼연구
• /
• 제26권4호
• /
• pp.166-178
• /
• 2018

In this study, the principal objective was to investigate the effect of light quality and vessel ventilation on the growth and development, physiology, activities of antioxidant enzymes, and contents of mineral nutrients of carnation (Dianthus caryophyllus L.) 'Marble Beauty'. Single node cuttings stuck into the plant growth regulator (PGR)-free MS medium in containers covered with caps with or without a ventilation filter were cultured first four weeks under white and then additional four weeks under either white (control), blue, red, or red + blue light emitting diodes (LEDs) for 56 days. Interestingly, a ventilated culture condition not only reduced the percentage of the hyperhydricity, but also increased the total chlorophyll content (Chl a + Chl b) of the plantlets as compared to the non-ventilated condition. In addition, blue LEDs produced plantlets with the greatest number of shoots and red LEDs produced plantlets with the greatest shoot length. The quality of plantlets was improved under a ventilation condition. Besides, under a ventilated condition, red + blue LEDs raised APX activity, and blue LEDs not only raised the activity of the CAT, but also increased tissue contents of such elements as K, Ca, Mg, Zn, Mn and Fe. The red LEDs increased contents of B and Si under a ventilated condition, and Na accumulation under a non-ventilated condition. Thus, including blue or red LEDs as the light source in a ventilated culture condition will produce plantlets of carnation 'Marble Beauty' in vitro with improved quality.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집B
• /
• pp.199-204
• /
• 2000

This paper reports a thermal environmental analysis of a room in accommodated with multi-heat sources according to ventilation condition. Two case modification have been investigated to obtain the lower temperature distribution in the room. The temperature distribution of the original room were found about $25{\sim}35^{\circ}C$. As a result, the use of, three ventilating fans and two electric fans are useful for room ventilation respectively, and using two electric fan is more recommendable in side of economical efficiency.

• 한국조리학회지
• /
• 제11권4호
• /
• pp.228-244
• /
• 2005

The objective of the study is to observe cooks first from the kitchen and those who care health and to grasp the impression regarding the kitchen environment. Also, it grasped the recognition degree of cooks against the elements of kitchen ventilation and kitchen ventilation equipments. We surveyed against 385 cooks who work in the kitchen of special grade hotels and family restaurants, used 5 scales for the object, and executed the analysis. The results of this study are as follows: (1) Health condition of the cooks appeared most highly pain in the shoulder and the neck. (2) for the impression regarding the kitchen environment, temperature was high and the insufficiency of ventilation is answered highly. (3) The importance of kitchen ventilation of cooks was recognized very high. (4) The combustion gas was recognized as very high percentage and the most effective element of the kitchen on the human body to remove first inside the kitchen. (5) Most cooks were recognized that the improvement of ventilation equipments is necessary. (6) The object of ventilation equipments is appeared to maintain comfortable kitchen environment. (7) The optimum operation method of ventilation equipment uses the automatic system of ventilation equipment from the kitchen and it is necessary to maintain the optimum. This research is based on preceding studies, investigating special grade hotels and family restaurants in Seoul. The ventilation plan of the kitchen should be accomplished to improve the health of cooks and productivity.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2002년도 추계학술발표대회
• /
• 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.

• 한국식품저장유통학회지
• /
• 제8권4호
• /
• pp.356-361
• /
• 2001

양파 간이저장시 노지야적에 의해 발생하는 부패를 감소시켜 망과의 안전저장을 위하여 조립식 간이하우스를 이용하여 통풍조건 및 통풍구 재료의 크기에 따른 저장성을 조사한 결과는 다음과 같다. 평균온도는 노지야적에 비해 강제통풍에서 0.3~3.6$^{\circ}C$높았고, 무통풍에 비해서는 1.4~8.2$^{\circ}C$가 낮았다. 그러나 처리간 유의차는 없었다. 상대습도는 통풍처리구에서 무통풍 및 노지야적에 비해 약간 높았다. 구중감소율은 노지야적에서는 2.5%, 무통풍에서는 2.9%, 자연통풍 2단에서는 3%, 강제통풍 2단에서는 4.3%였다. 8월 하순까지의 부패율은 자연통풍 2단 27.7%, 강제통풍 2단 25.4%,인데 비해 무통풍 34.6%, 노지야적 37.8%로 통풍처리구에서 부패가 적었다. 통붕구 재료의 크기가 클수록 평균기온은 조금 낮았고, 상대습도는 7월에 조금 높은 경향을 보이다가 8월 이후에는 차이가 거의 없었다. 통풍 파이프 표면의 풍속은 통풍구의 크기가 작을수록 강했으며, 부위별로는 중간부위가 양끝쪽보다 낮았다. 부패율은 75mm통풍구 17.9%, 100mm통풍구 15.3%, 125mm통풍구 14.1%로 통풍구 크기가 클수록 부패는 적었다.

• KIEAE Journal
• /
• 제4권3호
• /
• pp.203-210
• /
• 2004

This dissertation identifies and investigates the possible control modes of hybrid ventilation system in applying to general apartments. It evaluates range of hybrid ventilation control modes in terms of indoor air quality, thermal comfort, and energy consumption in a living room and a kitchen of the $1000m^2$ apartment. The TRNSYS simulation program was used for evaluating the following four ventilation types : A ventilation mode relying on only infiltration for supplying air, A natural ventilation mode considering with weather condition, A hybrid ventilation (natural + mechanical ventilation) mode allowing minimum ventilation with no heat exchange, and a hybrid ventilation mode with heat exchange. This study shows the following results. As temperature being controlled by heating cooling equipments, there is without significant difference in thermal performance among ventilation types. Regarding Indoor Air quality, Indoor air contamination level of the hybrid ventilation case consistently keep the lower levels. The hybrid ventilation modes consume more energy by a 49% as compared to the A ventilation mode relying on only infiltration for supplying air. It is caused by the continuous ventilation for keeping good indoor air quality; the increase of energy consumption can be attributable to the increase of the heating energy. Therefore, the heat exchange between indoor and outdoor air is required during heating season in severe weather conditions. During the cooling seasons, Introducing natural ventilation can achieve energy saving by 40 ~ 45%. Thus, it can be an effective strategies for energy saving. Based on these results, a hybrid ventilation system can be suggested as an effective ventilation strategy for archiving high level of indoor air quality, thermal comfort, and energy consumption.

• 한국식품과학회지
• /
• 제4권1호
• /
• pp.13-17
• /
• 1972

This experiment was conducted to observe the changes of composition of atmosphere in storage room by controlled ventilation under normal and sub-atmospheric conditions, and the biochemical changes in apple texture under these conditions. The results were as follows; 1) By controlled ventilation, concentration of carbon dioxide in storage room was optionally regulated and constantly maintained. 2) Among compositions of internal atmosphere of apple, especially, concentration of ethylene was much decreased at apple stored under sub-atmospheric condition than that stored under normal atmospheric condition. 3) Acidity of apple stored under sub-atmospheric condition was much greater than that of apple stored under normal atmospheric condition. 4) Respiratory quotients of apple, which was stored under normal and sub-atmospheric conditions, were shown to be high. But decarboxylation of added pyruvate was found more active in slices prepared from apple stored under sub-atmospheric condition.

• KIEAE Journal
• /
• 제11권3호
• /
• pp.31-36
• /
• 2011

People spend most of their time inside buildings recently, so the indoor air quality is one of the most important factors to human health. Furthermore, minimum energy use with proper ventilation systems for pleasant indoor environment is necessary because of energy shortage over the world. The concern to maintain proper indoor air quality at home has been increased, and a proper indoor air quality is continuously requested by the residents. By measuring and analyzing the density fluctuation of $CO_2$ through indoor humidity and testing personal reactions regarding comfort condition, we can obtain a way to effective ventilation. Heat and carbon dioxide emissions from resident's metabolism and construction materials could be the causes of indoor air pollution. If these materials stay indoors for a long time, it could directly influence the resident's health condition with diseases. It also leads massive energy use. Therefore, the way to save energy and to have effective control of indoor ventilation is needed. This study presented the control method of bedroom ventilation by $CO_2$ concentration change and subjective evaluation.

• Journal of Advanced Marine Engineering and Technology
• /
• 제30권1호
• /
• 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.