• Research Article

    Pre-Analysis Study on Ground Source Heat Pump System in Building with RETScreen

    RETScreen을 활용한 건물에서의 지열 히트펌프 시스템 적용 사전 분석연구

    Kim Yu Jin, Lee Kwang-Seob, Lee Euy-Joon, Kang Eun-Chul

    김유진, 이광섭, 이의준, 강은철

    Korea government published renewable energy obligation policy that public building must be supplied some part of total consumption energy (2019: 27%, 2020 ... + READ MORE
    Korea government published renewable energy obligation policy that public building must be supplied some part of total consumption energy (2019: 27%, 2020: 30%). RETScreen is freely available global energy tool that developed by Canadian National Energy Laboratory to quantify energy saving to compare conventional system. This program can be performed energy modeling, cost analysis, greenhouse gas emission analysis and financial analysis. In this study, GSHP (Ground source heat pump) heating and cooling system were studied for the energy deliverly and ROI (Return On Investment) in an office building. Three cases were studied according to the number of HP (Heat pump) units for the 1,000 m2 office building located in Daejeon. Results indicated that the energy delivery of the case 1 (1 HP unit) covered 57% of the office building heating and cooling energy consumption. The case 2 (2 HP units) covered 87.8% and the case 3 (3 HP units) covered 96.8% of the office building energy consumption. The ROI of the case 1 indicated 7.9 years. While 8.2 years for the case 2 and 9.7 years for the case 3. - COLLAPSE
    April 2020
  • Research Article

    Study on Long-term Performance of Phenolic Foam Insulation through Accelerated Aging Test

    가속화 시험을 통한 페놀폼 단열재의 장기성능 비교분석에 관한 연구

    Kim Jin-Hee, Kim Sang-Myung, Kim Jun-Tae

    김진희, 김상명, 김준태

    The application of the high-performance insulation materials for buildings seems to be an essential measure for reducing energy use in buildings. Phenolic ... + READ MORE
    The application of the high-performance insulation materials for buildings seems to be an essential measure for reducing energy use in buildings. Phenolic foam is a readily available insulation material with thermal conductivity of about 0.018 to 0.020 W/(mK). It has the advantage of higher thermal resistance and better fire resistance compared to other conventional building insulation materials. Insulation material used for building envelope is regarded as one of the decisive factors for building's energy load. Furthermore, the degradation of its thermal performance over time increasingly affects the building's energy use demand. Generally, the life span of conventionally built buildings is expected to be more than 50 years, so the long-term performance of insulation materials is critical. This paper aims to evaluate the long-term performance of phenolic form boards through an accelerated aging test. The tests were conducted according to BS EN 13166 and KS M ISO 11561. Based on the results of the accelerated aging test, the thermal performance variation of the material was analyzed, and then its aged value after 25 years was computed. Also, the characteristics of the phenolic foam board's long-term performance were also examined based on the standard testing methods adopted. - COLLAPSE
    April 2020
  • Research Article

    An Evaluation of Indoor Thermal Environment for Zero-Carbon Green Home according to the Operation Conditions in Summer

    제로카본 그린홈의 여름철 운영조건에 따른 실내 열환경 평가

    Yu Jung yeon, Cho Dong woo, Kim Kee Han

    유정연, 조동우, 김기한

    The Korean government has a plan to mandate zero-energy buildings in 2020 for public and 2025 for private buildings. In order to ... + READ MORE
    The Korean government has a plan to mandate zero-energy buildings in 2020 for public and 2025 for private buildings. In order to design a zero-energy building, insulation and airtightness, which are the most basic elements of passive house technology, are required, and the government has been accomplished this through step-by-step strengthening of related standards. In passive house with high thermal insulation and airtightness performance, the heat introduced into the building through solar radiation can be stored for a long time to keep the inside warm during winter. On the other hand, during summer, heat introduced into the building cannot be easily released to outside, so it is necessary to actively block solar radiation and high temperature outdoor air to prevent an increase of indoor temperature. Therefore, this study aims to derive an appropriate operation condition of passive house to maintain the indoor temperature at an suitable level according to the ventilation methods and solar shading conditions. As a result, under the conditions that the outdoor temperature was 28°C or less, the ventilation using a heat recovery ventilation system at daytime and natural ventilation at nighttime were selected for the most appropriate operation method. In addition, in the case of solar shading, it was found that blocking solar radiation at daytime using the blind and open the blind at nighttime to ensure natural ventilation were selected for the most appropriate solar shading condition. - COLLAPSE
    April 2020
  • Research Article

    Generation of Horizontal Global Irradiance using the Cloud Cover and Sunshine Duration According to the Solar Altitude

    일조시간 및 운량을 이용한 태양고도에 따른 수평면 전일사 산출

    Lee Kwan-Ho, Geoff J. Levermore

    이관호, 재프 리버모어

    This study compares cloud radiation model (CRM) and sunshine fraction radiation model (SFRM) according to the solar altitude using hourly sunshine duration ... + READ MORE
    This study compares cloud radiation model (CRM) and sunshine fraction radiation model (SFRM) according to the solar altitude using hourly sunshine duration (SD) and cloud cover (CC) data. Solar irradiance measurements are not easy for the expensive measuring equipment and precise measuring technology. The two models with the site fitting and South Korea coefficients have been analyzed for fourteen cities of South Korea during the period (1986-2015) and evaluated using the root mean square error (RMSE) and the mean bias error (MBE). From the comparison of the results, it is found that the SFRM with the site fitting coefficients could be the best method for fourteen locations. It may be concluded that the SFRM models of South Korea coefficients generated in this study may be used reasonably well for calculating the hourly horizontal global irradiance (HGI) at any other location of South Korea. - COLLAPSE
    April 2020