• Title/Summary/Keyword: Outdoor method

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Actual Energy Consumption Analysis of Temperature Control Strategies for Secondary Side Hot Water District Heating System with an Inverter (인버터시스템 적용 지역난방 시스템의 2차측 공급수 온도 제어방안에 따른 에너지사용량 실증 비교)

  • Cho, Sung-Hwan;Hong, Seong-Ki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.4
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    • pp.179-186
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    • 2015
  • In this study, the actual energy consumption of the secondary side District Heating System (DHS) with different hot water supply temperature control methods is compared. The two methods are Outdoor Temperature Reset Control and Outdoor Temperature Predictive Control. While Outdoor Temperature Reset Control has been widely used for energy savings of the secondary side system, the results show that the Outdoor Temperature Predictive Control method saves more energy. In general, the Outdoor Temperature Predictive Control method lowers the supply temperature of hot water, and it reduces standby losses and increases the overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, the Outdoor Temperature predictive Control method saves about 6.6% of energy when compared to the Outdoor Temperature Reset Control method. Also, it is found that at partial load condition, such as during daytime, the fluctuation of hot water supply temperature with Outdoor Temperature Reset Control is more severe than that with Outdoor Temperature Predictive Control. Thus, it proves that Outdoor Temperature Predictive Control is more stable even at partial load conditions.

Actual Energy Consumption Analysis on Temperature Control Strategies (Set-point Control, Outdoor Temperature Reset Control and Outdoor Temperature Predictive Control) of Secondary Side Hot Water of District Heating System (지역난방 2차측 공급수 온도 제어방안(설정온도 제어, 외기온 보상제어, 외기온 예측제어)에 따른 에너지사용량 실증 비교)

  • Cho, Sung-Hwan;Hong, Seong-Ki;Lee, Sang-Jun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.3
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    • pp.137-145
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    • 2015
  • In this study, the actual energy consumption of the secondary side of District Heating System (DHS) with different hot water supply temperature control methods are compared. Three methods are Set-point Control, Outdoor Temperature Reset Control and Outdoor Temperature Prediction Control. While Outdoor Temperature Reset Control has been widely used for energy savings of the secondary side of the system, the results show that Outdoor Temperature Prediction Control method saves more energy. In general, Outdoor Temperature Prediction Control method lowers the supply temperature of hot water, and it reduces standby losses and increases overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, Outdoor Temperature Prediction Control method saves about 7.1% in comparison to Outdoor Temperature Reset Control method and about 15.7% in comparison to Set-point Control method. Also, it is found that at when partial load condition, such as daytime, the fluctuation of hot water supply temperature with Set-point Control is more severe than Outdoor Temperature Prediction Control. Therefore, it proves that Outdoor Temperature Prediction Control is more stable even at the partial load conditions.

Measurement and Analysis of Exposure Opportunities for Outdoor Lighting (경관조명의 노출기회 측정 및 분석)

  • Park, Byoung-Chul;Choi, An-Seop
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.11a
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    • pp.173-178
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    • 2005
  • Outdoor lighting is an important factor of the urban scape. As a night image of the city, outdoor lighting acts important roles. Cities of developed countries have already had there own night images. Regarding this, government encourages outdoor lighting of building by various ways to building owners. However, in present, owners of private buildings have not been up and coming about outdoor lighting more than those of public buildings in our country. From this point of view, this paper suggests a quantification method for economic effects of outdoor lighting and analyzes economic effects of outdoor lighting in advertising. A suggested measurement method of economic effects is difficult to measure all economic effects of outdoor lighting. Therefore, this measurement method limits the target to the private buildings.

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An empirical method to determine a reverberation time in outdoor spaces of apartment complexes (아파트 단지 잔향시간 특성 및 예측 경험식 제안)

  • Yang, Hong-Seok;Kim, Myung-Jun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.880-884
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    • 2014
  • RT (reverberation time) of outdoor spaces surrounded by multi-storey buildings depends on many designable factors such as the openness, volume and building layouts, etc. This study therefore aims to clarify the influential factors for RT in outdoor spaces surrounded by buildings with complicated topographical conditions. A series of measurements were carried out for 15 outdoor spaces in 6 apartment complexes with different building layouts. An Empirical method considering the openness, averaged ray length and building high is also suggested, to predict RT approximately in the outdoor spaces. The overall results suggest that RT in outdoor spaces of apartment complexes is significantly influenced by source-receiver distance and building layouts.

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A Methodology Study for the Measurement of Outdoor Lighting Effects (경관조명의 효과측정을 위한 방법론 연구)

  • Park, Byoung-Chul;Choi, An-Seop
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.129-132
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    • 2005
  • Outdoor lighting is an important factor of urban scape. As a night image of the city, outdoor lighting acts important roles. Cities of developed countries have already had night images of their cites. About this, government is encouraging outdoor lighting of building by various ways. However, in present, outdoor lighting of headquarter buildings was not activated more than that of public buildings in our country. From this point of view, this paper presents a method to measure outdoor lighting effects as quantitative aspects for outdoor lighting activation. Presented the method of outdoor lighting effects is difficult to apply all buildings. Therefore, this paper limits the target to the headquarter buildings.

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

  • Hong, Goopyo;Hong, Jun;Kim, Byungseon Sean
    • KIEAE Journal
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    • v.16 no.6
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    • pp.13-19
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    • 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.

A Prediction on the Pollution Level of Outdoor Insulator with Regression Analysis (회귀분석을 활용한 옥외 절연물의 오손도 예측)

  • 최남호;구경완;한상옥
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.3
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    • pp.137-143
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    • 2003
  • The degree of contamination on outdoor insulator is ons of the most importance factor to determine the pollution level of outdoor insulation, and the sea salt is known as the most dangerous pollutant. As shown through the preceding study, the generation of salt pollutant and the pollution degree of outdoor insulator have a close relation with meteorological conditions, such as wind velocity, wind direction, precipitation and so fourth. So, in this paper, we made an investigation on the prediction method, a statistical estimation technique for equivalent salt deposit density of outdoor insulator with multiple linear regression analysis. From the results of the analysis, we proved the superiority of the prediction method in which the variables had a very close(about 0.9) correlation coefficient. And the results could be applied to establish the Pollution Prediction System for power utilities, and the system could provide an invaluable information for the design and maintenance of outdoor insulation system.

Analysis of Outdoor Design Temperatures for Heating and Cooling Greenhouses Based on Annual Percentiles (연간 백분위 방식에 의한 온실 냉난방 설계기온의 분석)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.27 no.3
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    • pp.269-275
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    • 2018
  • In order to establish the criterion for analyzing outdoor weather conditions in the greenhouse heating and cooling system design, we analyzed heating and cooling design outdoor temperatures by the annual percentile method and compared with design outdoor temperatures by the existing seasonal percentile method. In the annual percentile method, 0.4%, 1% and 2% of the total 8,760 hours per year are presented as cooling design outdoor temperatures and 99.6% and 99% as heating design outdoor temperatures. When the annual percentile method was adopted, heating design outdoor temperatures increased by 6.7 to 9.6% compared with the seasonal percentile method, and cooling design outdoor temperatures decreased by 0.6 to 1.1%. The maximum heating load in the same greenhouse condition decreased by 3.0 to 3.6% when the annual percentile method was adopted, but the effect on the maximum cooling load was insignificant. Therefore, it is necessary to consider the change of heating design outdoor temperatures to the annual percentile method, but it is not necessary to change the cooling design outdoor temperatures since there is little difference between the two methods.

A Study on the Planning of Outdoor Playground Space Open to the Community through the Participatory Design Method (사용자참여 디자인을 통한 열린 놀이터 만들기 - 서울 삼양초등학교 옥외공간을 중심으로 -)

  • Reigh, Young-Bum
    • Journal of the Korean Institute of Educational Facilities
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    • v.12 no.3
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    • pp.22-32
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    • 2005
  • This paper is to propose a design possibility that incorporates participatory process and also to emphasize the participatory process applied to the planning of outdoor playground space open to the neighboring community. Community design based on the participation method can be understood as an attitude about a force for change in the creation and management of environments for people who are the major users of them. Planning for outdoor space is an integral part of school education and a vital component of child development. For the design of outdoor space of Samyang Elementary School it first needs to examine the current and emerging needs of students, teachers and parents as community residents through the participatory design method. A series of workshops and interviews are taken to identify dreams and ideal spaces of each group. An assessment of existing school spaces and design possibility of reprogrammed outdoor spaces are proposed to match the major demands of participants. Selected outdoor places are chosen and designed to accommodate options for various play settings and to make the school pleasant places where members of the neighborhood can gather for relaxation in restful surroundings.

Experimental Study on Energy Saving Performance of Outdoor Temperature Reset Control Strategy for Central Cooling System (중앙 냉방시스템에 대한 외기보상제어의 절약 성능에 관한 실험적 연구)

  • Kim, Dong-Cheol;Song, Jae-Yeob;Ahn, Byung-Cheon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.7 no.2
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    • pp.30-36
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    • 2011
  • In this study, energy saving performance of outdoor temperature reset control strategy for central cooling system is researched by experiments. Outdoor temperature reset control is the control method to change indoor air set temperature according to outdoor air temperature change. The range of indoor air set temperature is represented by the comfort temperature range of indoor air temperature offered from ASHRAE and indoor air set temperature is programmed between $22^{\circ}C$ and $27^{\circ}C$ by outdoor air temperature $20^{\circ}C{\sim}32^{\circ}C$ in summer. As a result of applying outdoor temperature reset control to central cooling system, the suggested control method shows better performances of energy savings than the conventional method which indoor temperature maintains constantly.