• Title/Summary/Keyword: Indoor Air Temperature

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Seasonal Monitoring of Airborne Microbial Concentrations in Kindergartens (유치원의 실내환경에서 공기중 미생물 수의 계절적 변화)

  • Hwang, Gwang-Hwan;Lee, A-Mi;Sin, Hyeon-Jin;Kim, Jong-Seol
    • Korean Journal of Microbiology
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    • v.39 no.4
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    • pp.253-259
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    • 2003
  • To assess microbiological indoor air quality in kindergartens, concentrations of viable airborne microorganisms were seasonally determined at three kindergartens in Ulsan from April, 2002 to January, 2003. Sampling was performed with an impaction-type air sampler and three different media. The numbers of bacteria grown on Staphylococcus medium were between 84 and 4,150 MPN/m3 with an average of 827 MPN/m3, and those on standard method agar ranged from 50 to 2,636 MPN/m3 with an average of 580 MPN/m3. The bacterial concentrations were highest in summer, followed by fall, spring, and winter, and were significantly correlated with indoor temperature. Among the colonies, 45.6~61.0% were observed as Gram-positive cocci and 8.5~20.6% were Gramnegative rods. Micrococcus species were the dominant organisms. The numbers of fungi ranged from 0 to 1,888 MPN/m3(661 MPN/m3 average) based on colony counts with dichloran rose bengal chloramphenicol agar. On average, the fungal concentrations were highest in summer and lowest in winter. Penicillium species and Aspergillus species were identified from the colonies. The obtained data can be utilized as a step to set a guideline for bioaerosols in indoor environment of schools.

Development of Environmental Control Systems for Windowless Pig-housing (I) - Assessment of Control Performance - (무창돈사의 환경제어 시스템 개발 (I) - 제어성능의 평가 -)

  • 장홍희;장동일;임영일
    • Journal of Biosystems Engineering
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    • v.24 no.5
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    • pp.415-424
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    • 1999
  • This study was conducted to assess performances of the developed environmental control systems under various seasons of Korea. In all trials for the environmental control systems, the manure pit ventilation system in the windowless pig-housing with partly slatted floor was used. Consequently, under all seasons of Korea, the complex environmental control systems could comfortably maintain the indoor temperature (14.8~27.2$^{\circ}C$) , concentrations of noxious gases (CO2 gas : 631~1,874ppm, NH3 gas : 0.3~3.2ppm), air velocity (0.11~0.23m/s), air movement, and so on. Therefore, the performances of the complex environmental control systems were evaluated as proper as the intended.

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The Estimation of Cooling Load for District Cooling in Apartment Buildings (지역냉방 공동주택 적정 냉방부하 산정)

  • Kim, Sang-Hun;Byun, Woon-Seob
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.643-649
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    • 2008
  • The purpose of this study is to establish a standard for unit cooling load in central control type apartment applied district cooling. The model of unit household was selected. And the standard of coefficient of overall heat transmission, location of unit household, indoor air temperature, solar radiation & thermal conduction at window and interior load was selected, and region, expansion or non-expansion of balcony, pyeong type, azimuth, rate of window area was applied as parameter. And then cooling load simulation was performed. Based on the result of simulation, the synthetic district cooling load was presented for selecting heat source of apartment applied district cooling, and unit cooling load was analyzed according to design parameter.

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Study on Evaluation Analysis on Thermal Performance of Window Using A. S. Lab.(Artificial Solar Laboratory) (인공태양실험실(A. S. Lab.)을 활용한 창호의 열성능 평가에 관한 연구)

  • Kang, Ki-Nam;Lee, Keon-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.11
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    • pp.812-819
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    • 2010
  • Recently residential buildings are characterized with high-rise and high density. Under this circumstance, achieving comfortable and healthy indoor environment with minimized energy consumption becomes a very challenging engineering and societal issue. Along this the increased size and transparency of window as well as light surface caused by high stories lowers the heat shield efficiency of building. Since glass that constitutes building surface has low heat efficiency, it aggravates heat loss of all building considerably, thereby resulting in extreme heating load and cooling load in the country where temperature varies much in summer and winter. The research will check whether experiment can be effectively done by overcoming the limit of existing artificial solar laboratory constructed in the country and properly adjusting controlled variables with simplified function through construction of this experimental set.

Experimental Study on the Evaluation of Heat Transfer Characteristics of Buildings' External Walls -Focusing on the winter heat transfer characteristics of four experimental model buildings in accordance with the location of insulation- (건물(建物) 외벽(外壁)의 전열특성(傳熱特性) 평가(評價)에 관한 실측(實測) 연구(硏究) - 단열재 위치에 따른 실험용 건물의 겨울철 열특성 평가를 중심으로 -)

  • Sohn, J.Y.;Yoon, D.W.;Park, J.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.1 no.3
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    • pp.228-234
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    • 1989
  • This paper describes the experimental thermal performance results of four experimental model buildings insulated differently. For the purpose of examining the thermal characteristics of external walls and indoor thermal conditions, four experimental model buildings are constructed as externally insulated, internally insulated, non-insulated &light-weight curtain wall types with different K-values and heat capacities, respectively.
    Through the measurements of temperatures at various points and solar insolation, the effects of insulation and heat capacities are evaluated, and the evaluated effects of each experimental model buildings are compared. Hence, the characteristics of temperature profiles, time-lag effects and decrement factors are discovered.

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Analysis of basic IAQ management factors in KTX passenger cabin (KTX 객실의 IAQ 관리 기초 인자 분석)

  • Cho Young-Min;Park Duckshin;Park Byunghyun;Park Eunyoung
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.1153-1158
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    • 2005
  • The passenger cabin of train is generally insulated from exterior environment to ensure the safety of passengers and to enhance the heating and cooling efficiency. Therefore, the IAQ management of passenger cabin is very important in aspect of amenity and health of passengers. In this study, we measured some IAQ factors influencing on the indoor air quality of passenger cabin. The measurement was carried out to investigate the PM-10, PM-2.5, PM-1.0, temperature, relative humidity, carbon monoxide, carbon dioxide leves of KTX. The results showed that the air quality of the cabin was largely satisfactory, but carbon dioxide level was relatively higher. The control of carbon dioxide levels need the extensive research in the future.

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Multiple Units Control of Boiler and Refrigerator in HVAC System (공조용(空調用) 열원기기(熱源機器)의 대수분리(臺數分離) 제어(制御)에 관한 연구(硏究))

  • Sohn, J.Y.;Kim, H.S.;Ahn, B.W.;Shin, Y.T.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.4 no.1
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    • pp.1-10
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    • 1992
  • The purpose of this paper is to provide an efficient method of operating and designing HVAC systems for reasonable energy consumption in building. Accroding to the conditions of indoor temperature and humidity, and the methods of dividing and grouping the capacity of boiler and refrigerator, the amount of their annual energy consumptions is simulated by using an energy analysis program which is developed in this paper, and opatimal design methods of HVAC system are suggested as well.

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Recent Progress in Air Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2007 (설비공학 분야의 최근 연구 동향 : 2007년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Shin, Dong-Sin;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.12
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    • pp.844-861
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    • 2008
  • The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.

A Comparative Analysis on Cooling Energy of Heat Recovery Ventilator and Air Handling Unit in the Office Building (사무용 건물에서 전열교환 환기시스템과 일반공조기의 냉방에너지 비교분석에 관한 연구)

  • Jang, Ji-Hoon;Kim, Hyeonsoo;Auh, Jin-Sun;Leigh, Seung-Bok;Kim, Byungseon-Sean
    • KIEAE Journal
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    • v.16 no.6
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    • pp.123-128
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    • 2016
  • Purpose: In order to save the energy consumption of buildings, buildings have been constructed with high performance insulation or airtightness. However, high performance insulation or air tightness has led to a poor indoor air quality. Therefore, HRV(Heat Recovery Ventilator) has received attention to save the energy consumption and insure a good air quality. Because existing research is almost about the performance of HRV in residential buildings, This study analyzed the effect of HRV on cooling energy consumption in commercial office building. Method: This study was proceeded at commercial office building in In-cheon. In order to evaluate the energy consumption of HRV, this study proposed two methods: estimating energy consumption of the room installed AHU(Air Handling Unit) system; estimating energy consumption of the room installed HRV system. Therefore, comparison of two methods was proceeded to evaluate energy performance of each method. Result: As the result of comparison between rooms installed AHU and HRV, the experiment showed that energy consumption of the room installed HRV system is about 22% less than the room of AHU system. This conclusion is considered because the room installed HRV system have maintained temperature well at set point temperature $26^{\circ}C$.

Study on Optimal Control Algorithm of Electricity Use in a Single Family House Model Reflecting PV Power Generation and Cooling Demand (단독주택 태양광 발전과 냉방수요를 반영한 전력 최적운용 전략 연구)

  • Seo, Jeong-Ah;Shin, Younggy;Lee, Kyoung-ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.10
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    • pp.381-386
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    • 2016
  • An optimization algorithm is developed based on a simulation case of a single family house model equipped with PV arrays. To increase the nationwide use of PV power generation facilities, a market-competitive electricity price needs to be introduced, which is determined based on the time of use. In this study, quadratic programming optimization was applied to minimize the electricity bill while maintaining the indoor temperature within allowable error bounds. For optimization, it is assumed that the weather and electricity demand are predicted. An EnergyPlus-based house model was approximated by using an equivalent RC circuit model for application as a linear constraint to the optimization. Based on the RC model, model predictive control was applied to the management of the cooling load and electricity for the first week of August. The result shows that more than 25% of electricity consumed for cooling can be saved by allowing excursions of temperature error within an affordable range. In addition, profit can be made by reselling electricity to the main grid energy supplier during peak hours.