• Journal of Energy Engineering
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• v.15 no.3 s.47
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• pp.194-201
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• 2006

Greenhouses should be heated during nights and cold days in order to fit growth conditions in greenhouses. Ground source heat pump (GSHP) systems are recognized to be outstanding heating and cooling systems. A horizontal GSHP system with thermal storage tank was installed in greenhouse and investigated the performance characteristics. The reasons for using thermal storage tank were discussed in detail. Thermal storage tank can provide heat for heating load that is larger than GSHP system heating capacity. The results of study showed that the heating coefficient of performance of the heat pump system was 2.69.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.643-658
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• 2015

This study presents detailed emission of greenhouse gases of using Clean Energy Agriculture System according to a cradle-to-gate life-cycle assessment, including emission from energy use and leak of Biogas. Calculations were done with the PASS software and the covered gases are $CH_4$, $N_2O$ and $CO_2$, Total GHG fluxes of amount to $1719.03kgCO_2/day$, $39.63kgCO_2/day$ (2.31%) are from facility house process, $0.19kgCO_2/day$ (0.01%) are from transport process, $696.72kgCO_2/day$ (40.53%) are from Anaerobic digestion process, $846.61kgCO_2/day$ (49.25%) are from Heating and cooling system, $135.88kgCO_2/day$ (7.90%) are from Fertigation production process. The results suggest that for effective reduction of GHG emissions from Facility house using clean energy. Reduction targets should address both the production process as defined by IPCC sectors and the consumption process. An LCA assessment as presented here could be a basis for such efforts.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.447-452
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• 2007

Greenhouses should be heated during nights and cold days in order to fit growth conditions in greenhouses. Ground source heat pump(GSHP) or geothermal heat pump system(GHPs) is recognized to be outstanding heating and cooling system. Horizontal GSHP system is typically less expensive than vertical GSHP system but requires wide ground area to bury ground heat exchanger(GHE). In this study, a horizontal GSHP system with thermal storage tank was installed in greenhouse and investigated as performance characteristics. In the daytime, heating load of greenhouse is very small or needless because solar radiation increases inner air temperature. The results of study showed that the heating coefficient of performance of the heat pump ($COP_h$) was 2.9 and the overall heating coefficient of performance of the system($COP_{sys}$) was 2.4. Heating energy cost was saved 76% using the horizontal GSHP system with thermal storage tank.

• Asian review of World Histories
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• v.2 no.1
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• pp.1-16
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• 2014

This paper examines the historical relationship between the Little Ice Age and the Anthropocene, which has not yet been studied. The Little Ice Age is the coldest multi-century period in the Holocene. The reforestation of huge farmlands, abandoned due to pandemics in the Americas, aggravated the cooling weather of the Little Ice Age. It was in the long and severe cold of the Little Ice Age that the transition from renewable energy to non-renewable energy was completed in Britain in the latter part of the eighteenth century, and when the pattern of linear growth in greenhouse gas concentrations was forged in the ecosystems of the Earth. The Little Ice Age forced humans to depend on fossil fuels while the advent of warmer and more stable climate in the Holocene enabled them to start agriculture in an energy revolution 11,000 years ago, thus making the coming of the Anthropocene possible.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.473-483
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• 2014

In this work, the effects of shade combination, shade height and wind regime on greenhouse climate were quantified. A two-dimensional (2-D) computational fluid dynamics (CFD) model was developed based on an 11-span plastic greenhouse in eastern China for wind almost normal to the greenhouse orientation. The model was first validated with air temperature profiles measured in a compartmentalized greenhouse cultivated with mature lettuce (Lactuca sativa L., 'Yang Shan'). Next, the model was employed to investigate the effect of shade combinations on greenhouse microclimate patterns. Simulations showed similar airflow patterns in the greenhouse under different shade combinations. The temperature pattern was a consequence of convection and radiation transfer and was not significantly influenced by shade combination. The use of shade screens reduced air velocity by $0.02-0.20m{\cdot}s^{-1}$, lowered air temperature by $0.2-0.8^{\circ}C$ and raised the humidity level by 0.9-2.0% in the greenhouse. Moreover, it improved the interior climate homogeneity. The assessment of shade performance revealed that the external shade had good cooling and homogeneity performance and thus can be recommended. Furthermore, the effects of external shade height and wind regime on greenhouse climate parameters showed that external shade screens are suitable for installation within 1 m above roof level. They also demonstrated that, under external shade conditions, greenhouse temperature was reduced relative to unshaded conditions by $1.3^{\circ}C$ under a wind speed of $0.5m{\cdot}s^{-1}$, whereas it was reduced by merely $0.5^{\circ}C$ under a wind speed of $2.0m{\cdot}s^{-1}$. Therefore, external shading is more useful during periods of low wind speed.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.281-287
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• 1999

In order to take a good look at effectiveness of cooling of Fog system and Pad-Fan system, we chose 49 farm households which were installed evaporative cooling system and 2 farm households which were installed Pad-Fan system and Fog system for a test. We execute the test on 29 households out of 49.6 households, which were installed Pad-Fan system, were able to use; however, 6 household out of 9 which were installed Fog system couldn't use it. The main reason was the clogged on nozzle. The cooling efficiency on Pad-Fan system was 77.4%, but it was very poor on Fog system. Since there are many problems on Fog system, we need more research on size of fog, the location of nozzle, control of Fog systems.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.04a
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• pp.25-29
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• 2002

대부분의 작물이 생육하기에 적합한 지온은 18-2$0^{\circ}C$정도이고 최고한계는 23-$25^{\circ}C$로 알려져 있으나, 여름철 온실내의 지온은 이보다 높으며 2001년 8월에 온실내의 지온을 계측해본 결과 표층으로부터 5-35cm 깊이의 평균 지온은 27-29.4$^{\circ}C$까지 상승하는 것으로 나타났다(김 등, 2001). 따라서 지중 냉각의 필요성이 인정되며, 정 등(1998)의 보고에 의하면 무처리시 지온 25.7$^{\circ}C$에 대하여 지하수 냉각으로 지온을 19-19.6$^{\circ}C$로 냉각해줄 경우 배추 수량이 8-11% 증수되었다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.32-35
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• 1998

최근 온실이 현대화, 대형화, 고정화 및 자동화와 함께 주년생산을 위한 년중 재배체계가 도입되면서, 여름철 작물의 생육환경 조성을 개선하기 위하여 기존의 방법보다 더욱 적극적인 냉방시스템을 활용하게 되었다. 지금까지 알려진 여름철 주간 온실냉방방식에는 여러 가지 있으나, 그 중에서 물의 기화열을 이용한 패드 ㆍ 팬방식, 미스트 ㆍ 팬방식, 포그 ㆍ 팬방식의 증발냉각법이 주를 이루고 있다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.10a
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• pp.178-184
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• 2005

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.103-106
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• 1995

최근 시설재배 면적이 급증하고 있는 것에 부응하여 시설을 이용한 작물의 주년안정생산에 관한 연구가 활성화되고 있다. 그러나 여름철의 고온극복과 냉방에 관한 연구는 아직까지도 많은 어려움을 겪고 있다. 우리나라와 같이 사계절이 뚜렷한 기후여건에서는 겨울철의 난방 및 보온에 못지 않게 여름철의 냉방 및 고온극복 대책이 주년안정생산에 있어서 빼놓을 수 없는 중요한 과제가 아닐 수 없다. (중략)