• Title, Summary, Keyword: Outdoor air cooling

Search Result 202, Processing Time 0.038 seconds

An Analysis of Heating and Cooling Energy and Effect on Outdoor Air Cooling according to Building Type of Apartment Complex (공동주택 단지의 주동형식에 따른 냉난방 에너지 및 외기냉방 효과 분석)

  • Roh, Ji-Woong
    • Journal of the Korean Solar Energy Society
    • /
    • v.34 no.4
    • /
    • pp.31-38
    • /
    • 2014
  • This study makes three apartment building complex an object of analyzing representative building types and energy consumption rate of house holds, and effect of outdoor air cooling. Recently created apatrment complex is composed of very various types of building, plan, and orientation etc. But, it is difficult to remark conclusively that these various types of buildings are designed energy-effectively. Because architects are hard to find useful energy design guideline for decision making. By the preceding study, the present condition and problem about this subject is grasped, apartment building types were examined and representative types were extracted. In this study, energy simulation was conducted, and the effect to outdoor air cooling was analyzed about representative types of the subject apartment complex. It is expected that this analysed results will be basic data for the more integrated study. Research consequence can be summarized as follow: 1) Besides solar gain, household layout of building, orientation, and plan etc. effects compositively on energy consumption rate. 2) The effect of ourdoor air cooling in building of tower type can be improved by arranging households appropriately.

An Experimental Study on Control Performance of Radiant Floor Cooling Using Ondol (온돌을 이용한 바닥복사냉방의 제어성능에 관한 실험적 연구)

  • 김용이;임재한;한여명;김광우
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.13 no.11
    • /
    • pp.1165-1173
    • /
    • 2001
  • The objectives of this study are to analyze the application of radiant floor cooling and to evaluate the control methods through experiments when the radiant heating system is used for cooling. Through the experiment analysis the control methods such as on/off control, variable flow control and outdoor reset with indoor temperature feedback control are evaluated and compared. The cooling curve (reset ratio) is found for radiant cooling, which shows tole relation between outside air temperature and supply water temperature. Comparison of cooling methods shows that outdoor reset with indoor temperature feedback control is more appropriate than on/off control and variable flow control with regard to prevention of the condensation and thermal comfort.

  • PDF

The Possibility on Utilization of Underground Pit for Reduction of Cooling and Heating Load (냉방과 난방 부하 감소를 위한 지하피트의 이용 가능성)

  • Cho Sung-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.18 no.2
    • /
    • pp.144-150
    • /
    • 2006
  • The purpose of this study is to predict outlet temperature and humidity through underground pit for the reduction of cooling load and heating load. Commonly, the underground temperature is lower than outdoor in summer but the reverse happens in winter. When the outdoor average air temperature is $25.7^{\circ}C$ during cooling periods, the average outlet air temperature through underground pit is $23.6^{\circ}C$ with 3 m-depth and 60m-length and is $22.2^{\circ}C$ with 3 m-depth and 150 m-length. When the outdoor average air temperature is $4.9^{\circ}C$ during heating periods, the average outlet air temperature through underground pit is $7.7^{\circ}C$ with 3m-depth and 60 m-length and is $10.8^{\circ}C$ with 3 m-depth and 150 m-length. The outlet air temperature is affected by more length than depth of underground pit. The diffusion ratio of outdoor humidity is $-7.7\times10^{-8}kg/s$ in cooling periods and $9.29\times10^{-7}kg/s$ in heating periods.

The Performance Analysis and On-site Performance Test of a Dedicated Outdoor Air System (외기 전용 공조기의 성능 분석 및 현장 성능시험)

  • Kim, Young-Il;Kim, Jung-Min;Chung, Kwang-Seop;Park, Seung-Tae
    • Proceedings of the SAREK Conference
    • /
    • /
    • pp.346-351
    • /
    • 2007
  • Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional cooling+reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 48.8% less equivalent energy that conventional system. The on-site performance test of the prototype shows that the coefficient of performance(COP) of the DOA system is 37.4% higher than the conventional system.

  • PDF

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

  • Song, Gen-Soo;Yoo, Kyung-Hoon;Kang, Shin-Young;Son, Seung-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.21 no.5
    • /
    • 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.

A Study on Correlation of Outdoor Environmental Condition about Cooling Load (냉방부하에 영향을 미치는 외기 환경조건의 상관관계에 관한 연구)

  • Lee, Je-Myo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.24 no.11
    • /
    • pp.759-766
    • /
    • 2012
  • To estimate the cooling load for the following day, outdoor temperature and humidity are needed in hourly base. But the meteorological administration forecasts only maximum and minimum temperature. New methodology is proposed for predicting hourly outdoor temperature and humidity by using the forecasted maximum and minimum temperature. The correlations for normalized outdoor temperature and specific humidity has been derived from the weather data for five years at Seoul, Daejeon and Pusan. The correlations for normalized temperature are independent of date, while the correlations for specific humidity are linearly dependent on date. The predicted results show fairly good agreement with the measured data. The prediction program is also developed for hourly outdoor dry bulb temperature, specific humidity, dew point, relative humidity, enthalpy and specific volume.

Operation Cost Comparison of Dedicated Outdoor and Cooling + reheating Air-conditioning Systems by On-site Performance Test (현장성능시험에 의한 외기전용과 냉각식 + 재열 공조기의 운전비 비교)

  • Kim, Young-Il;Kim, Jung-Min;Chung, Kwang-Seop;Park, Seung-Tae
    • Transactions of the Korea Society of Geothermal Energy Engineers
    • /
    • v.7 no.2
    • /
    • pp.37-42
    • /
    • 2011
  • Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional Cooling + reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 50% less equivalent energy than the conventional system. The on-site performance test of a prototype shows that the coefficient of performance(COP) of the DOA system is 37% higher than the conventional system.

Performance Simulation of a Ventilation System Adopting a Regenerative Evaporative Cooler (재생증발식 냉방기를 이용한 환기 냉방시스템의 성능해석)

  • Chang, Y.S.;Lee, D.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.23 no.1
    • /
    • pp.8-15
    • /
    • 2011
  • Cooling load reduction was analysed of a ventilation system adopting a regenerative evaporative cooler. The regenerative evaporative cooler is a kind of indirect evaporative cooler which cools the air down to its inlet dewpoint temperature in principle without change in the humidity ratio. The regenerative evaporative cooler was found able to cool the ventilation air to $18{\sim}21^{\circ}C$ when the outdoor condition ranges $25{\sim}35^{\circ}C$ and 0.01~0.02 kg/kg. When the outdoor humidity ratio is lower than 0.018 kg/kg, the regenerative evaporative cooler was found to provide cooling performance enough to compensate the ventilation load completely and to supply additional cooling as well. Energy simulation during the summer was carried out for a typical office building with the ventilation system using the regenerative evaporative cooler. The results showed that the seasonal cooling load can be reduced by about 40% by applying the regenerative evaporative cooler as a ventilation conditioner. The reduction was found to increase as the outdoor temperature increases and the outdoor humidity ratio decreases.

Analysis of Energy Reduction of Free Cooling System with Regions of South Korea (지역별 프리쿨링 시스템의 에너지 절감 분석)

  • Yoon, Jung-In;Son, Chang-Hyo;Choi, Kwang-Hwan;Baek, Seung-Moon;Heo, Jeong-Ho;Kim, Young-Min
    • Journal of the Korean Solar Energy Society
    • /
    • v.34 no.3
    • /
    • pp.82-88
    • /
    • 2014
  • Using low outdoor temperature, free cooling system is used in a data center or industrial air-conditioning for energy saving. Because use of IT equipment has increased in some office building recently, there is a growing trend towards using free cooing system. Free cooling system performance is influenced by outdoor temperature. Therefore the performance is different with regions. In this study, performance characteristic of free cooling system is analysed and energy reduction is compared with some regions. Selected regions are 4 cities; including Ulsan analyzed in preceding research, Seoul, ChunCheon and Daejeon. The Aspentech software HYSYS 8.0v was used to conduct the analysis of free cooling system based on temperature per hour of 4 cities in 2013, respectively. The main result is following as. Free cooing system in this study has energy saving effect when outdoor temperature below $7^{\circ}C$. Becuase temperature of Chuncheon is relatively low, using free cooling system can conserve most air-conditioning energy. Energy reduction amount of Seoul is 11%, Chuncheon is 17.5%, Deajeon is 15%, Ulsan is 14%. In case of large scale of air-conditioning, it is reasonable to use free cooling system although the system is used in Seoul.

DOAS/CRCP 시스템 설계

  • Jeong, Jae-Weon
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.35 no.12
    • /
    • pp.41-48
    • /
    • 2006
  • For the Designing a Dedicated Outdoor Air System with Ceiling Radiant Cooling Panels the concept of a dedicated outdoor air system(DOAS) with parallel sensible cooling was born from the decoupled system concept, which can be summarized as decoupling of ventilation and air-conditioning functions, or decoupling of sensible and latent load functions. First , remove the latent loads from the outside air(OA) intake and generated in spaces using a 100% OA ventilation system(i.e., DOAS). Second, remove the space sensible loads using a parallel mechanical cooling system, such as fan coil units, conventional variable air volume , and ceiling radiant cooling panel(CRCP) independent of the ventilation system.

  • PDF