한국건축친환경설비학회 논문집 · 한국건축친환경설비학회

Research Article

A Comparison of Airtightness according to Airtight Quality Construction in Multi-unit Residential Buildings
공동주택 단위 세대의 기밀 품질 시공에 따른 기밀성능 비교

Ji, Kyung-Hwan, Lee, Dong-Seok, Jo, Jae-Hun
지경환, 이동석, 조재훈

Recently, interest in passive building techniques has been increased to improve the energy efficiency of buildings. Accordingly, airtightness has become increasingly emphasized ... + READ MORE

Recently, interest in passive building techniques has been increased to improve the energy efficiency of buildings. Accordingly, airtightness has become increasingly emphasized to reduce energy costs of heating and cooling attributable to infiltration and exfiltration. In this study, we compared airtightness value for apartment and mixed-use residential buildings, and evaluated the airtightness according to the airtightness quality construction. We conducted airtightness measurement using fan pressurization method for 37 units in 3 residentail buildings. As a result, the airtightness of the apartment unit was measured airtight. The airtightness was poorly measured for units with a drywall. And the airtightness was measure at a level of about one-third of the building with airtight quality construction. - COLLAPSE

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June 2021
Research Article

Evaluation of the Usefulness of the Drain Back System to Prevent Overheating and Freezing for Facade installed Solar Hot Water System for School Building
수직 벽면형 태양열 온수급탕 시스템의 학교건물 적용을 위한 드레인백 시스템의 과열 및 동파방지 유용성 평가

Joo, Hong-Jin, Lee, Kyoung-Ho, An, Young-Sub, Lee, Wang-Je
주홍진, 이경호, 안영섭, 이왕제

In this study, a drain back system to prevent summer season overheating and winter season freezing of facade installed solar hot water ... + READ MORE

In this study, a drain back system to prevent summer season overheating and winter season freezing of facade installed solar hot water system for school building was suggested and evaluated by long-term experiments. The drain back system proposed in this study was configured as a system with a control valve to modulate the amount of drained water when drain-back is called. The controller of the drain-back system allows the user to set the set point temperature and control whether to remain or discharge the working fluid inside the piping of the solar hot water system. In addition, the piping system was constructed so that a part of the working fluid pump power recovered by installing a micro hydro turbine with a capacity of 10 W at the end of the return pipe of the solar hot water system. In order to experimentally evaluate the reliability and usefulness of the drain back system to prevent overheating and freezing, long-term demonstration experiments were carried out to use tap water that is vulnerable to freezing and overheating as a working fluid. As a result of long-term experiments, the temperature inside the heat storage tank could be kept below the setting temperature of 68℃ in the summer season. Also, the freezing problem of the solar hot water system did not occur at all even when the outside temperature was continuously below -10℃ in the winter season. - COLLAPSE

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June 2021
Research Article

Performance Improvement and Comparative Evaluation of the Chiller Energy Consumption Forecasting Model Using Python
Python을 이용한 냉동기 에너지소비량 예측 모델의 성능 개선 및 비교 평가

Lee, Cheol-Won, Seong, Nam-Chul, Choi, Won-Chang
이철원, 성남철, 최원창

In this study, Python is used to predict chiller energy consumption and improve the performance of forecasting models. The forecasting model used ... + READ MORE

In this study, Python is used to predict chiller energy consumption and improve the performance of forecasting models. The forecasting model used a random forest model and an artificial neural network model. To improve the performance of the forecasting model, the accuracy was evaluated by adjusting the number of inputs and the training data size. As a result, for the random forest model, the prediction performance allowed by the criteria was shown from the number of input variables to seven, and the CvRMSE improved the prediction performance by up to 23.91% by increasing the number of inputs. The training data size was shown to have acceptable predictive performance for the criterion at 80% and increased the training data size, improving the predictive performance by up to 14.08%. For artificial neural network (ANN) models, the predictive performance allowed by the criterion was shown to have a predictive performance with four inputs, and the CvRMSE improved by up to 14.90% by increasing the number of inputs. The training data size was shown to have acceptable predictive performance for the criterion at 70% and the maximum increase in the training data size resulted in improved predictive performance by up to 11.99% for CvRMSE. Comparing the two models, the artificial neural network model has better predictive performance than the random forest model, and the model for improving predictive performance is also more advantageous for the use of input variables and the adjustment of training data size. - COLLAPSE

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June 2021
Research Article

In-situ Method for Calculation of the Linear Thermal Transmittance of Wall-window Joints using Infrared Thermography
열화상을 활용한 현장측정 기반의 창-벽체 접합부 선형열관류율 산출 방법

Kim, Chang-Min, Choi, Jae-Sol, Kim, Eui-Jong, Jang, Hyang-In
김창민, 최재솔, 김의종, 장향인

The occurrence of defects in wall-window joints directly affects occupants. However, there are challenges in measuring defects quantitatively due to the lack ... + READ MORE

The occurrence of defects in wall-window joints directly affects occupants. However, there are challenges in measuring defects quantitatively due to the lack of evaluation standards. Therefore, this study proposes a digital twin-based method for calculating the linear thermal transmittance of wall-window joints using thermal images, and verifies its applicability. The applicability of the proposed field measurement-based linear thermal transmittance calculation method was verified by reproducing the results through chamber tests. The chamber tests were performed by fabricating specimens with construction defects, setting the internal and external temperatures to a dynamic state, and measuring the thermal images at four different time points. As a result of applying the proposed method, the maximum error of linear thermal transmittance between the four time points was 6.32%. The results demonstrate the possibility of quantitatively measuring defects in wall-window joints. - COLLAPSE

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June 2021
Research Article

A Study on the Capacity Estimation of Photovoltaic System Applied to Multi-Unit Dwelling by Zero Energy Building Certification Grade
제로에너지건축물 인증을 고려한 공동주택 태양광 발전시스템 적용 방안

Won, Jong-Yeon, Tae, Yeong-Ran
원종연, 태영란

This study examined the applicable capacity of the photovoltaic system of two blocks of the apartment complex for each ZEB certification grade ... + READ MORE

This study examined the applicable capacity of the photovoltaic system of two blocks of the apartment complex for each ZEB certification grade through a solar simulation program. District heating is applied to the two blocks of the apartment, and the Ⓐ block is higher-rise than the Ⓑ block. Accordingly, since the Ⓐ block has a relatively long district heating pipe length and pumping power, the primary energy requirement was calculated to be higher. As a result of calculating the PV applicable area of the roof and the facade using the solar simulation program, the roof was found to be in the range of 54 to 73% depending on the building arrangement, and it was analyzed that the average of 65% was applicable. The facade was found to be available as much as 15% of the total facade area in the southeast and 20% in the southwest. As a result of applying the PV system according to the ZEB certification grade, it was analyzed that up to Grade4 can be achieved only by the rooftop area, and it was found that the facade area from Grade3 should be available. As the maximum achievable level, Ⓐ block was analyzed as ZEB Grade3 and Ⓑ block as Grade2. - COLLAPSE

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June 2021
Research Article

A Practical Method for Mitigating the Trouble with the Heavyweight Floor Impact Sound: Wearing Indoor Shoes
층간소음 분쟁 완화를 위한 현실적 대안의 모색: 실내화 착용

No, Tae-Hak, Joo, Mun-Ki, Oh, Yang-Ki
노태학, 주문기, 오양기

In spite of many advantages on energy efficiency and amenities in life, apartment house has a critical problem in floor impact noise ... + READ MORE

In spite of many advantages on energy efficiency and amenities in life, apartment house has a critical problem in floor impact noise, particularly heavy weight floor impact noise between floors. 50 dB of minimum performance and 210 mm of floor slab thickness were proposed and coded by Korean law and building code system since 2003 to mitigate the impact noise conflict. But there have been still many apartment houses which haven’t met the minimum performance level due to the shallow slabs and the other factors. In this paper, a practical solution to relieve the conflict between above and underneath floors due to the floor impact noise was proposed and verified, wearing indoor shoes. The characteristics and reduction of the impact sound were measured and analyzed in various conditions. The results showed that the lower the dynamic stiffness of indoor shoes buffer, the better the reduction level. The effect of wearing indoor shoes was concentrated on the 50-160 Hz frequency ranges, which affects the single number of the heavy floor impact sound. Unlike single impact sound when slow walking, a difference of 7.3-9.7 ㏈ was shown in the 50-160 ㎐ frequency ranges, which influenced the evaluation value of the heavy floor impact sound. And for girls, there was a difference of 8-11.9 ㏈. Because it is difficult to reduce the low-frequency band noise of heavy floor impact sounds, it is considered wearing indoor shoes is a very positive result as realistic alternative. - COLLAPSE

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June 2021
Research Article

Performance Evaluation of Hot Water Flow Rate Control through Differential Pressure Control for Radiant Heating System in Apartment Buildings
공동주택 복사난방 시스템의 차압제어를 통한 온수유량 제어 성능 평가

Rhee, Kyu-Nam, Jung, Gun-Joo
이규남, 정근주

In hydronic networks of apartment buildings with radiant heating systems, an excessive flow rate can be supplied to the household due to ... + READ MORE

In hydronic networks of apartment buildings with radiant heating systems, an excessive flow rate can be supplied to the household due to increased pressure difference, usually under part load conditions. To deal with this problem, test-rig experiments and hydronic network simulations were conducted to investigate the control performance of pressure difference controllers such as flow limit valve (FLV) and pressure difference control valve (PDCV). To do this, a test-rig and Flowmaster simulation models were developed to analyze the flow rate and pressure difference under part load conditions in hydronic networks. The results showed that the FLV could reduce the maximum flow rate, however, excessive flow rate was still caused because the large pressure difference was not mitigated under low-part load conditions. It was found that the PDCV was effective in preventing excessive flow rate, because it could maintain a stable pressure difference even under low-part load conditions. Pressure difference and flow quotient charts were also suggested to evaluate the control performance depending on part load conditions in apartment buildings. - COLLAPSE

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June 2021