• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.341-347
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• 2009

Experiments and computations were conducted to investigate the heat insulation characteristics of multi layer materials for cultivation greenhouse. In case of the experiments, measurements of temperature were carried out with a K-type thermocouples and data logger to research the heat transfer in the experimental module generated by the heat source. A thermal conductivity meter, QTM-500 based on modified transient hot wire method was used to measure the thermal conductivity of multi layer materials. The numerical analyses were performed by commercial code CFX-11 according to the variation of multi layer materials without air layer. The experimental results showed that the heat insulation of multi layer materials was higher than single layer materials by 50~90%. It was found that the effect of heat insulation was raised by the combination of multi layer materials.

• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.89-95
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• 2007

This study was accomplished to compare energy saving effects of several heat insulation materials in greenhouse and to develop new automatic opening and closing equipment which is suitable to the most effective heat insulation material. To find out more effective heat insulation material, the magnitude of heat transfer occurred through aluminum screen (ALS), non-woven fabric (NWF), double-layer aluminum screen with chemical cotton sheet (DAL), and multi-layer fabric screen material quilted with non-woven fabric, chemical cotton, poly foam, and polypropylene (MLF) were compared relatively. The results showed that the relative magnitude of heat transfer occurred through MLF was lower than DAL and ALS by 23.3% and 43.0% respectively. MLF screen material was the most effective compared with other heat insulation materials. But because of thickness, there was a need of new mechanism for automatic operation in greenhouse. Accordingly, new screen system using MLF-thick but profitable for keeping warm in greenhouse-was developed. Opening & closing equipment was designed to roll MLF with pipe axis during opening process and pull MLF with string during closing process with electric motors, clutches, drums, and so on. In hot pepper cultivation and energy saving test during winter time, the early stage yield of pepper under MLF screen system was higher than NWF by 27%, and gasoline consumption of MLF screen system was lower than NWF by 46%.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.255-264
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• 2019

In this study, we conducted the hot box tests to compare the changes in thermal insulation for the four types of multi-layer thermal screens by the used period after collecting them from the greenhouses in the field when they were replaced at the end of their usage. The main materials for these four types of multi-layer thermal screens were matt georgette, non-woven fabrics, polyethylene (PE) foam, chemical cotton, etc. These materials were differently combined for each multi-layer thermal screen. We built specimens ($70{\times}70cm$) for each of these multi-layer thermal screens and measured the temperature descending rate, heat transmission coefficient, and thermal resistance for each specimen through the hot box tests. With regard to the material combinations of multi-layer thermal screens, thermal insulation can be increased by applying a multi-layered PE foam. However, it is considered that the multi-layered PE foam significantly less contributes to heat-retaining than chemical wool that forms an air-insulating layer inside multi-layer thermal screens. For the suitable heat-retaining performance of multi-layer thermal screens, basically, materials with the function of forming an air-insulating layer such as chemical cotton should be contained in multi-layer thermal screens. The temperature descending rate, heat transmission coefficient, and thermal resistance of multi-layer thermal screens were appropriately measured through the hot box tests designed in this study. However, in this study, we took into consideration only the four kinds of multi-layer thermal screens due to difficulties in collecting used multi-layer thermal screens. This is the results obtained with relatively few examples and it is the limit of this study. In the future, more cases should be investigated and supplemented through related research.

• 월간 기계설비
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• s.312
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• pp.96-97
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• 2016

건설현장의 자재는 종류가 다양하기 때문에 이를 관리하기란 쉬운 일이 아니다. 보온재 또한 크기와 모양이 비슷하기 때문에 복잡하고 다양한 배관작업을 수행하는 우리 기계설비건설업체 공사현장에서는 규격이 다른 보온재를 설치하여 금전적 손실로 이어질 위험이 크다. 이에 따라 이번호에 KS인증 표시기준을 준수하는 발포 폴리에틸렌 보온재의 제품인증 표시 확인 방법에 대해 알아본다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.64-66
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• 1995

시설하우스용 보온커튼지의 부직포는 시설에 이용되는 보온재중 그 비중이 15.9% 수준에 불과하나 최근 원예시설의 현대화 대형화 사업으로 급속히 증가하고 있는 추세로 온도관리에서 열에너지 절감에 매우 주요한 시설자재이다. 그러나, 시설원예의 구조와 환경관리에 관한 연구가 많은 반면, 보온커튼지의 중요성에 비추어 보온커튼지의 부직포에 관한 물리적 기계적성질이나 광투과성 및 보온성에 관한 연구는 매우 미진한 실정이다. (중략)

• 월간 기계설비
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• s.19
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• pp.92-97
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• 1991

2백만호 주택건설을 비롯한 국내건설경기의 활황이 연 3년째 지속되고 있는 가운데 자재난, 인력난, 노임단가의 급상승 등은 건설경기의 활황 이면에 어두운 그림자를 던져주고 있다. 특히 자재가격의 상승 및 구득난은 공사원가의 상승 및 공기의 자연 등으로 이어져 건설경기의 압박요인으로 작용하고 있는 것이다. 이러한 현상은 설비공사업계에도 미치고 있는 것으로서 만성적인 자재구득난의 하나로 지적되어온 위생도기류는 대량 수입과 생산시설의 증가 등으로 해소될 기미를 보이고 있으나 최근들어 유리면보온재 및 밸브류, 강관, 주철관등은 아직도 구득이 어려운 실정이다. 본지는 설비공사업계에서 심각한 구득난을 빚고 있는 보온재, 위생도기, 밸브류 등을 차례로 점검, 진단해 본다.

• Korean Architects
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• no.1 s.142
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• pp.76-79
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• 1981

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.332-340
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• 2009

In this study, the thermal insulation effectiveness of the greenhouse insulators by the installation methods was investigated to find the right installation way of the insulation materials. Physical properties of the insulators such as thickness, air transmissivity, apparent density, ultraviolet rays cutoff ratio, reflectance, thermal conductivity, moisture absorptivity were evaluated and the insulation ability of the insulators were measured by the module experiments. For the same insulator, the insulation ability of the case with the outward direction of the black colored face, i.e., with the inward direction of the white colored face, was better than that of vice versa. The case of the black colored both surfaces was better than the case of the white colored both surfaces. For aluminium reflection material, the case with the outward direction of the lustre face, i.e., with the inward direction of the non-lustre face, was better than that of vice versa. For the same material with the inner thin polyethylene foam (or polyester) and the chemical wool, the case with the outward direction of the inner thin polyethylene foam (or polyester), i.e., with the inward chemical wool, was better than that of vice versa. Addition of the inner thin polyethylene foam increased the insulation effect very much.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.227-233
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• 2018

The purpose of this study was to develop a warm cover for greenhouse with excellent thermal insulation and to propose ways of commercialization of the product. Feathers were used as filling materials because they formed the air layer to enhance insulation. Instead of downs for clothing or other textile products, we used disposed feathers. The developed product covers the outside of the greenhouse to keep the crops warm. It has multiple layers including feathers as filling materials, padding, inside fabric, heat insulation materials and outer fabric. It has proven to improve the insulation ratio. We developed other kinds of warm covers that are applicable to the inside of the greenhouse or the small houses in the greenhouse. Also, R&D system of educational industrial complex enables us to commercialize the products and building marketing strategies for them. This technology contributes to the expansion of energy-saving facilities for farmers, and it can serve the development and spread of various products utilizing feather.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.251-257
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• 2004

This experiment was carried out to investigate the effects of different covering materials and methods on heat insulation of a plastic greenhouse, growth and yield of tomato. Night air and soil temperatures in a double-layer greenhouse with external multifold thermal cover (MTC; eight-ounce cassimere+four-fold polyform+double-fold non-woven fabric+single-fold polypropylene covering were about $1^{\circ}C$ lower than in that with internal MTC covering, but about $3^{\circ}C$ higher than in that with an EVA film screen. Tomato yield in the external MTC covering increased by $2\%\;and\;19\%$ as compared to that in the internal MTC covering and the non-covering of MTC, respectively, due to its high light transmission and insulation effect. Night air temperatures in a double-layer greenhouse with external MTC covering and with thermal screen (polyester plus aluminium) were $2.2^{\circ}C\;and\;4.5^{\circ}C$ higher than those in a double-layer greenhouse with an external MTC covering and in a double-layer greenhouse equipped an EVA film screen, respectively. Tomato yield in the treatment with external MTC covering and a thermal screen was $18\%\;and\;37\%$ greater than that in the external MTC covering and in an EVA film screen, respectively. Results indicate that tomato could be grown without heating or with minimal heating in a double-layer greenhouse covered with MTC and a thermal screen during the winter season in sourthern regions of Korea.