• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.274-277
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• 2011

We measured a solar irradiation of vertical and horizontal surface per azimuth in southern area of Korea using pyrheliometer. In comparison with the provided data from ASHRAE and CIBSE, the average amount of solar irradiation has much variation of 10 to 150% in reference with north direction. In the clear day, the measured value has much difference with the value of ASHRAE and there is similar trend in case of CIBSE. The reason why amount of irradiation of clear day is differ from the average value, is able to be assumed that the value of ASHRAE and CIRSE is made of assumption based on clear days. The result of analysis of ASHRAE and CIBSE values according to the amount irradiation value for vertical and horizontal surface per azimuth using the MBE, RSME, and t-Statistic show that the CIBSE value has more reliability for the MBE, RMSE, and t-Statistic values than ASHRAE value.

• Advances in Energy Research
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• 제8권2호
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• pp.111-123
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• 2022

Solar Energy is the energy of solar radiation carried by them in the form of heat and light. It can be converted into electricity. Solar potential depends on the site's atmosphere; the solar energy distribution depends on many factors, e.g., turbidity, cloud types, pollution levels, solar altitude, etc. We estimated solar radiation with the help of the Ashrae clear-sky model for three locations in Pakistan, namely Pasni, Gwadar, and Jiwani. As these locations are close to each other as compared to the distance between the sun and earth, therefore a slight change of latitude and longitude does not make any difference in the calculation of direct beam solar radiation (BSR), diffuse solar radiation (DSR), and global solar radiation (GSR). A modified formula for declination angle is also developed and presented. We also created two different models for Ashrae constants. The values of these constants are compared with the standard Ashrae Model. A good agreement is observed when we used these constants to calculate BSR, DSR, GSR, the Root mean square error (RMSE), Mean Absolute error (MABE), Mean Absolute percent error (MAPE), and chisquare (χ²) values are in acceptance range, indicating the validity of the models.

• 태양에너지
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• 제12권1호
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• pp.15-24
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• 1992

태양열이용 LiBr-water 흡수식 냉난방시스템의 시간단위의 simulation model을 SuperCalc spreadsheet를 사용해서 제시하였고 전체시스템의 열성능을 분석함으로써 spreadsheet simulation 방식의 가치를 입증하였다. Arizona, Tucson에 위치한 사무실형 건물의 시간단위의 냉난방 부하를 ASHRAE 방식에 의하여 계산하였으며 전체 시스템의 구성요소 및 제어 방식에 대한 알고리즘을 제시하였다. 두 종류의 흡수식 시스템의 열성능을 시스템 매개변수를 이용해서 비교하였다.

• 설비공학논문집
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• 제1권3호
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• pp.210-218
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• 1989

The ASHRAE Simplified Energy Analysis Procedure using the Modified Bin Method(SEAP) is compared with the hourly calculation program, HASP/ACLD. The HASP/ACLD model office building with VAV system in Seoul is used as the basis for comparison. And the parameters considered are glass to wall area ratio and internal heat gains. The results show that SEAP predictions of annual energy use agree with HASP/ACLD predictions within 5% deviation. But there is a large difference in cooling and heating energy as glass to wall area ratio is varied. The SEAP cooling energy is 65-85% and the heating energy is 104-160% of the HASP/ACLD results. This is probably due to the solar heat gain data. the data related to the SEAP must be developed prior to use it.

• 설비공학논문집
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• 제29권10호
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• pp.497-503
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• 2017

In recent years, studies on the prediction of building load using Artificial Neural Network (ANN) models have been actively conducted in the field of building energy In general, building loads predicted by ANN models show a sharp deviation unless large data sets are used for learning. On the other hands, some of the input data are hard to be acquired by common measuring devices. In this work, we estimate daily building loads with a limited number of input data and fewer pastdatasets (3 to 10 days). The proposed model with fewer input data gave satisfactory results as regards to the ASHRAE Guide Line showing 21% in CVRMSE and -3.23% in MBE. However, the level of accuracy cannot be enhanced since data used for learning are insufficient and the typical ANN models cannot account for thermal capacity effects of the building. An attempt proposed in this work is that learning procersses are sequenced frequrently and past data are accumulated for performance improvement. As a result, the model met the guidelines provided by ASHRAE, DOE, and IPMVP with by 17%, -1.4% in CVRMSE and MBE, respectively.

• Architectural research
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• 제25권4호
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• pp.73-84
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• 2023

Indoor thermal conditions greatly affect the health and comfort of humans who occupy the space in it. The purpose of this research is to analyze the influence of water and vegetation elements as a microclimate modifier in buildings to obtain thermal comfort through the study of thermal environment models. This research covers two objects, namely public buildings and housing in Makassar City, South Sulawesi Prov-ince - Indonesia. Quantitative methods through field surveys and measurements based on thermal and personal variables. Data analysis based on ASHRAE 55 2020 standard. The data was processed with a parametric statistical approach and then simulated with the Computational Fluid Dynamics (CFD) simulation method to find a thermal prediction model. The model was made by increasing the ventilation area by 2.0 m2, adding 10% vegetation with shade plant characteristics, moving water features in the form of fountains and increasing the pool area by 15% to obtain PMV + 0.23, PPD + 8%, TSV-1 - +0, Ta_25.7℃, and relative humidity 63.5 - 66%. The evaluation shows that the operating temperature can analyze the visitor's comfort temperature range of >80% and comply with the ASHRAE 55-2020 standard. It is concluded that water elements and indoor vegetation can be microclimate modifiers in buildings to create desired comfort conditions and adaptive con-trols in buildings such as the arrangement of water elements and vegetation and ventilation systems to provide passive cooling effects in buildings.

• 터널과지하공간
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• 제27권3호
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• pp.132-145
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• 2017

과거 도로터널 환기에 있어서 충격 손실은 설계에 반영되지 않았지만, 터널 내 네트워크형 구조로 인해 분기 합류부가 존재하는 복층 도로터널에서는 충격 손실에 의한 압력 손실이 크게 발생할 것이다. 이에 본 연구에서는 네트워크형 구조를 가지는 복층 도로터널 최적 환기 설계를 위하여 분기 합류 지점에서 발생하는 충격 손실에 대한 3D 전산유체역학(CFD) 수치해석 연구를 수행한다. 이를 위해 복층 도로터널 표준단면을 적용한 실제 스케일 모델을 활용하여 전산 유체 역학을 수행하였고 다양한 각도와 차도폭에 대한 충격 손실 계수를 도출하여 기존의 설계 값과 비교 분석하였다. 연구 결과, 분기 구간에서는 30도의 분류 각도를 가진 모델의 충격 손실 계수가 높게 측정되었고, 합류 구간에서는 2차선으로 설계된 모델의 충격 손실 계수가 낮게 측정됨을 확인할 수 있었다. 따라서 분기 합류 각도와 차도폭이 충격 손실 산정에 있어서 중요한 설계 요소가 될 수 있으므로 환기기 용량 산정에 있어서 정확한 설계 인자를 제시할 것으로 판단된다. 본 연구는 3D 전산유체역학(CFD)를 활용하여 확폭 교차 유 무에 따른 분기 합류 지점에서의 충격 손실 계수를 도출하고, ASHRAE 설계 값과 결과를 비교 분석하였다. 확폭 구간이 반영되지 않은 모델은 ASHRAE 값에 비해 최대 3배의 충격 손실 값을 확인하였고, 확폭 구간이 반영된 모델은 최대 2배의 값을 확인할 수 있었다.

• 한국태양에너지학회 논문집
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• 제30권2호
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• pp.72-80
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• 2010

The main thrust of this paper is to investigate a practical way of generating the monthly averaged daily horizontal solar radiation in Korea. For estimating the horizontal solar radiation, the clearness index($K_T$) and the clearness number($C_N$) which are required for the use of Liu and Jordan's model and ASHRAE Clear Sky model were derived based on the measured weather data. Third-order polynomials returning $K_T$ and��$C_N$ for a given location were derived as a function of cloud amount, month, date, latitude and longitude. The predicted monthly averaged daily horizontal solar radiation values were compared with those acquired from the established design weather data. The MBE(Mean Bias Error) and RMSE (Root Mean Squares for Error) between the predicted values and the measured data were near zero. It means that the suggested third-order polynomials for $K_T$ and $C_N$ have good applicability to Liu and Jordan's model and ASHRAE Clear Sky model.

• 대한건축학회논문집:구조계
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• 제34권12호
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• pp.65-72
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• 2018

The purpose of this study is to predict vertical illuminance accurately at the design stage of a building without the help of simulation tools. Comparing two well-known vertical illuminance prediction algorithms with measured values, it is verified that the Igawa model is more consistent with the measured values than the Perez model. Using the DIVA program, we simulated the vertical illuminance at 30-degree intervals from south to north, compared with the vertical illuminance calculated with the Igawa model. The result of calculation values were verified from 120 degrees east to 120 degrees west. The vertical illuminance values with each of three shade devices were calculated using the Igawa model, and compared with the vertical illuminance simulated by DIVA program. As a result, all the errors when installing horizontal / vertical / grid shade divices were included in the error standard specified by ASHRAE.

• 한국지열·수열에너지학회논문집
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• 제14권1호
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• pp.16-21
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• 2018

This work aims to develop a platform to investigate the effect of operation schedules on the building energy consumption and to derive a simulation model based optimal start and stop daily strategy. An open-source building energy simulation tool DOE2 is used for the engine, and the developed simulation model is validated using ASHRAE guideline 14. The effect of late-start/early-stop operation of HVAC system on the daily building energy consumption was analyzed using the developed simulation model. It was found that about 10% of energy consumption cut was possible using the control strategy for an hour of advance of the stop operation, and about 3% per an hour of delay of the start operation.