• 제목/요약/키워드: outdoor air

검색결과 972건 처리시간 0.02초

외기상태의 변화에 따른 실내 환경인자의 민감도 분석 (Sensitivity Analysis of Indoor Environment Factors along with Changes of Outdoor Air Condition)

  • 조석호
    • 한국환경과학회지
    • /
    • 제19권2호
    • /
    • pp.125-136
    • /
    • 2010
  • The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. A sensitivity analysis of indoor environment factors was carried out to grasp influences along with changes of atmospheric conditions. An integrated multizone model was used to predict these sensitivities. This model was applied to an apartment with six zones. Airflow rates are influenced very seriously by changes of wind direct or wind velocity, but are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air temperatures are influenced very directly by changes of outdoor air temperature, but are influenced very slightly by wind direction or wind velocity and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air humidities are influenced very directly by changes of outdoor air humidity, but are not influenced at all by changes of outdoor air contaminant concentration and have little or no influence by changes of wind direction, wind velocity, or outdoor air temperature. Indoor air contaminant concentrations are influenced very seriously by changes of wind direct or wind velocity, but are influenced somewhat by changes of outdoor air contaminant concentration and are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity.

반도체 클린룸용 증기가습 및 수분무가습 외기공조시스템의 에너지소비량 평가 (An Assessment of Energy Consumption in Steam-Humidification- and Water-Spray-Humidification-Type Outdoor Air Conditioning Systems for Semiconductor Manufacturing Clean Rooms)

  • 김기철;송근수;김형태;유경훈;신대건;박덕준
    • 설비공학논문집
    • /
    • 제25권2호
    • /
    • pp.55-63
    • /
    • 2013
  • For a large-scale semiconductor manufacturing clean room, the energy consumed in an outdoor air conditioning system to heat, humidify, cool and dehumidify incoming outdoor air is very large. In particular, the energy requirement to humidify outdoor air in the winter season is generally known to be high. Recently, in order to overcome the high energy consumption nature of a steam generator in a conventional steam humidification type outdoor air conditioning system, an air washer is often introduced instead of the steam generator in the outdoor air conditioning system, which can be called a water spray humidification type outdoor air conditioning system. Therefore, the assessment and comparison of the annual energy consumed in the steam humidification type and the water spray humidification type outdoor air conditioning systems deserves to be examined in order to reduce the outdoor air conditioning load of a clean room. In the present study, a numerical analysis was conducted to obtain the annual electric power consumption of the two outdoor air conditioning systems. It was shown from the comparison of the numerical results that the water spray humidification type outdoor air conditioning system can reduce about 30% of annual electric power consumption of the steam humidification type outdoor air conditioning system.

반도체 클린룸용 에어와셔 외기공조시스템의 에너지소비량에 관한 실험적 연구 (An Experimental Study on Energy Consumption of Air Washer Outdoor Air Conditioning Systems for Semiconductor Manufacturing Clean Rooms)

  • 김기철;김형태;송근수;유경훈;손승우;신대건;박덕준
    • 설비공학논문집
    • /
    • 제24권4호
    • /
    • pp.297-305
    • /
    • 2012
  • In recent large-scale semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems to heat, humidify, cool and dehumidify incoming outdoor air represents about 45% of the total air conditioning load required to maintain a clean room environment. Therefore, the energy performance evaluation and analysis of outdoor air conditioning systems is useful for reducing the outdoor air conditioning load for a clean room. In the present study, an experiment was conducted to compare the energy consumption of outdoor air conditioning systems with a simple air washer, an exhaust air heat recovery type air washer and a DCC return water heat recovery type air washer. It was shown from the present lab-scale experiment with an outdoor air flow of 1,000 $m^3/h$ that the exhaust air heat recovery type and DCC return water heat recovery type air washer outdoor air conditioning systems were more energy-efficient for the summer and winter operations than the simple air washer outdoor air conditioning system and furthermore, the DCC return water heat recovery type one was the most energy-efficient in the winter operation.

Energy Saving Potential and Indoor Air Quality Benefits of Multiple Zone Dedicated Outdoor Air System

  • Lee, Soo-Jin;Jeong, Jae-Weon
    • 국제초고층학회논문집
    • /
    • 제8권1호
    • /
    • pp.71-82
    • /
    • 2019
  • The purpose of this study is to evaluate the indoor air quality (IAQ) and energy benefits of a dedicated outdoor air system (DOAS) and compare them with a conventional variable air volume (VAV) system. The DOAS is a decoupled system that supplies only outdoor air, while reducing its consumption using an enthalpy wheel. The VAV system supplies air that is mixed outdoor and transferred indoor. The VAV has the issue of unbalanced ventilation in each room in multiple zones because it supplies mixing air. The DOAS does not have this problem because it supplies only outdoor air. That is, the DOAS is a 100% outdoor air system and the VAV is an air conditioning system. The transient simulations of carbon dioxide concentration and energy consumption were performed using a MATLAB program based on the thermal loads from the model predicted by the TRNSYS 18 program. The results indicated that when the air volume is large, such as in summer, the distribution of air is not appropriate in the VAV system. The DOAS however, supplies the outdoor air stably. Moreover, in terms of annual primary energy consumption, the DOAS consumed approximately 40% less energy than the VAV system.

부하예측 외기냉방에 의한 건물에너지 절약에 관한 연구 (A Study on Building Energy Saving using Outdoor Air Cooling by Load Prediction)

  • 김태호;유성연;김명호
    • 설비공학논문집
    • /
    • 제29권2호
    • /
    • pp.43-50
    • /
    • 2017
  • The purpose of this study is to develop a control algorithm for outdoor air cooling based on the prediction of cooling load, and to evaluate the building energy saving using outdoor air cooling. Outdoor air conditions such as temperature, humidity, and solar insolation are predicted using forecasted information provided by the meteorological agency, and the building cooling load is predicted from the obtained outdoor air conditions and building characteristics. The air flow rate induced by outdoor air is determined by considering the predicted cooling loads. To evaluate the energy saving, the benchmark building is modeled and simulated using the TRNSYS program. Energy saving by outdoor air cooling using load prediction is found to be around 10% of the total cooling coil load in all locations of Korea. As the allowable minimum indoor temperature is decreased, the total energy saving is increased and approaches close to that of the conventional enthalpy control.

반도체 클린룸용 배기 열회수식 외기공조시스템의 에너지절감에 관한 실험적 연구 (An Experimental Study on Energy Reduction of an Exhaust Air Heat Recovery Type Outdoor Air Conditioning System for Semiconductor Manufacturing Clean Rooms)

  • 송근수;유경훈;강신영;손승우
    • 설비공학논문집
    • /
    • 제21권5호
    • /
    • pp.273-281
    • /
    • 2009
  • In recent semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems represents about 45% of the total air conditioning load required to maintain a clean room environment. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery from the exhaust air is therefore useful for reducing the outdoor air conditioning load for a clean room. In the present work, an energy-efficient outdoor air conditioning system was proposed to reduce the outdoor air conditioning load by utilizing an air washer to recover heat from the exhaust air. The proposed outdoor air conditioning system consisted mainly of a preheating coil, an air washer, two stage cooling coils, a reheating coil, a humidifier and two heat recovery cooling coils inserted into the air washer and connected to a wet scrubber. It was shown from the lab-scale experiment with outdoor air flow of $1,000\;m^3/h$ that the proposed system was more energy-efficient for the summer and winter operations than an outdoor air conditioning system with a simple air washer.

변풍량 공조시스템의 요구외기량 확보를 위한 제어방식 (Control Methods of the VAV Air Handling Unit for the Required Outdoor Air Demand)

  • 한도영;주영덕;김진;이준호
    • 설비공학논문집
    • /
    • 제15권3호
    • /
    • pp.203-209
    • /
    • 2003
  • Control algorithms of an air handling unit by using the mixing box plenum pressures were developed and verified by experiments. Control algorithms developed for this study were the setpoint algorithms for the outdoor damper position, the outdoor/fixed plenum pressure, and the return/exhaust plenum pressure. The outdoor/fixed plenum pressure setpoint was used to control the bypass damper position, and the return/exhaust plenum pressure setpoint was used to control the return fan speed. Experimental results showed the good control of the required outdoor air demand. Therefore, setpoint algorithms developed for this study may effectively be applied for the control of the VAV air handling unit.

Calculation of Outdoor Air Fraction through Economizer Control Types during Intermediate Season

  • Hong, Goopyo;Hong, Jun;Kim, Byungseon Sean
    • KIEAE Journal
    • /
    • 제16권6호
    • /
    • pp.13-19
    • /
    • 2016
  • Purpose: In this study, we examined outdoor air fraction using historical data of actual Air Handling Unit (AHU) in the existing building during intermediate season and analyzed optimal outdoor air fraction by control types for economizer. Method: Control types for economizer which was used in analysis are No Economizer(NE), Differential Dry-bulb Temperature(DT), Diffrential Enthalpy(DE), Differential Dry-bulb Temperature+Differential Enthalpy(DTDE), and Differential Enthalpy+Differential Dry-bulb Temperature (DEDT). In addition, the system heating and cooling load were analyzed by calculating the outdoor air fraction through existing AHU operating method and control types for economizer. Result: Optimized outdoor air fraction through control types was the lowest in March and distribution over 50% was shown in May. In case of DE control type, outdoor air fraction was the highest of other control types and the value was average 63% in May. System heating load was shown the lowest value in NE, however, system cooling load was shown 1.7 times higher than DT control type and 5 times higher than DE control type. For system heating load, DT and DTDE is similar during intermediate season. However, system cooling load was shown 3 times higher than DE and DEDT. Accordingly, it was found as the method to save cooling energy most efficiently with DE control considering enthalpy of outdoor air and return air in intermediate season.

사계절 외기 전용 공조기에 대한 실험적 연구 (An Experimental Study on Four-season Dedicated Outdoor Air Handling Unit)

  • 박승태;김종천;홍영주;김영일
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2008년도 하계학술발표대회 논문집
    • /
    • pp.577-582
    • /
    • 2008
  • The present study has been conducted to study the performance of Dedicated outdoor air handling unit. Dedicated outdoor air handling unit consists of pre-cooler, dehumidification and after cooler. By combining dedicated outdoor air-conditioning and heat pump, a new four-season dedicated outdoor air handling unit has been developed. Amount of energy saved and condition when this new system is superior to conventional vapor-compression cooling system has been presented.

  • PDF

외기 도입에 따른 바닥급기 시스템의 에너지 사용량 분석 (Analysis of the Energy Consumption in Underfloor Air Distribution System depending on Outdoor Air Intake Rates)

  • 김동희;허정호;조동우;유기형;유지용
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2006년도 하계학술발표대회 논문집
    • /
    • pp.826-831
    • /
    • 2006
  • In this paper, we discussed the energy performance of underfloor air distribution(UFAD) and overhead air distribution system according to outdoor air intake rates in a office building. For this, the laboratory(S lab.) is selected for measuring the thermal environments of UFAD system and overhead system. Based on the measured data, the TRNSYS simulation is used to evaluate the energy performance of UFAD system and the overhead system according to outdoor air intake rates. By increasing outdoor air intake rates from required outdoor air intake rates(100CMH) to maximum air intake rates, the energy savings of UFAD system comparing with overhead system are varied $15%{\sim}25.6%$ in summer, $12.8%{\sim}19%$ in fall/spring and not varied in winter(8%). As results of simulations on stratification height and cooling set temperature, the lower the stratification height and the higher cooling set temperature, the larger cooling energy savings of UFAD comparing with overhead system according to outdoor air intake rates.

  • PDF