Simulation and control of ventilation rates in greenhouses

Dayan, J.; Dayan, E.; Strassberg, Y.; Presnov, E.

doi:10.1016/j.matcom.2003.09.017

Cited by 30 publications

(9 citation statements)

References 28 publications

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“…Greenhouse screening by insect netting can cause a significant decrease in turbulence (Katsoulas et al 2006; Kittas et al 2008) depending on the type of netting. Bartzanas et al (2004), Dayan et al (2004) and Kittas and Bartzanas (2007) simulated airflow and temperature patterns under different regimes finding similar results. Shilo et al (2004) suggested that air flows in the lower part of the greenhouse were mostly not directed toward the windows but rather toward the ground and to the sides.…”

Section: Discussionmentioning

confidence: 66%

Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

et al. 2011

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Greenhouses are a well-accepted containment strategy to grow and study genetically modified plants (GM) before release into the environment. Various containment levels are requested by national regulations to minimize GM pollen escape. We tested the amount of pollen escaping from a standard greenhouse, which can be used for EU containment classes 1 and 2. More specifically, we investigated the hypothesis whether pollen escape could be minimized by insect-proof netting in front of the roof windows, since the turbulent airflow around the mesh wiring could avoid pollen from escaping. We studied the pollen flow out of greenhouses with and without insect netting of two non-transgenic crops, Ryegrass (Loliummultiflorum) and Corn (Zea Mays). Pollen flow was assessed with Rotorod® pollen samplers positioned inside and outside the greenhouse’ roof windows. A significant proportion of airborne pollen inside the greenhouse leaves through roof windows. Moreover, the lighter pollen of Lolium escaped more readily than the heavier pollen of Maize. In contrast to our expectations, we did not identify any reduction in pollen flow with insect netting in front of open windows, even under induced airflow conditions. We conclude that insect netting, often present by default in greenhouses, is not effective in preventing pollen escape from greenhouses of wind-pollinated plants for containment classes 1 or 2. Further research would be needed to investigate whether other alternative strategies, including biotic ones, are more effective.Electronic supplementary materialThe online version of this article (doi:10.1007/s10453-011-9237-8) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 66%

Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

et al. 2011

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“…In addition, the temperature and humidity ratios were higher closer to the roof, while air velocity was greater near the crops. Dayan et al [80] developed a simplified model to calculate the rate of ventilation in a greenhouse used for growing roses and obtained a good agreement between the predicted numerical values and the validation experiment. They used this model to demonstrate the influence of forced ventilation on canopy and plant temperatures.…”

Section: Ventilation-based Coolingmentioning

confidence: 86%

Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods

2019

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The projected increase of the world’s population, coupled with the shrinking area of arable land required to meet future food demands, is building pressure on Earth’s finite agricultural resources. As an alternative to conventional farming methods, crops can be grown in protected environments, such as traditional greenhouses or the more modern plant factories. These are usually more productive and use resources more efficiently than conventional farming and are now receiving much attention—especially in urban and peri-urban areas. Traditionally, protected cropping has been predominantly practised in temperate climates, but interest is rapidly rising in hot, arid areas and humid, tropical regions. However, maintaining suitable climatic conditions inside protected cropping structures in warm climates—where warm is defined as equivalent to climatic conditions that require cooling—is challenging and requires different approaches from those used in temperate conditions. In this paper, we review the benefits of protected cropping in warm climates, as well as the technologies available for maintaining a controlled growing environment in these regions. In addition to providing a summary of active cooling methods, this study summarises photovoltaic (PV)-based shading methods used for passive cooling of greenhouses. Additionally, we also summarise the current humidity-control techniques used in the protected cropping industry and identify future research opportunities in this area. The review includes a list of optimum growing conditions for a range of crop species suited to protected cropping in warm climates.

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“…Many researchers have studied control strategies for ventilation and heating systems, for humidification/dehumidification systems, and for the regulation of other agricultural greenhouse parameters. References [14,15] proposed a ventilation system based on an on-off control, Reference [16] studied a natural ventilation system for an agricultural greenhouse, Reference [17] presented an evaluation of the use of various renewable energy sources to heat a greenhouse, and Reference [18] introduced different fields of application for renewable energy in buildings, in particular in the agricultural sector. Reference [19] proposed energy reduction measured through low-cost and solar energy-based sensors.…”

Section: Introductionmentioning

confidence: 99%

Intelligent Control of the Microclimate of an Agricultural Greenhouse Powered by a Supporting PV System

et al. 2020

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An agricultural greenhouse is a complex and Multi-Input Multi-Output MIMO system in which the internal parameters create a favorable microclimate for agricultural production. Temperature and internal humidity are two parameters that have a major impact on greenhouse yield. The objective of this study was to propose a simulated dynamic model in a MATLAB/Simulink environment for experimental validation. Moreover, a fuzzy controller was designed to manage a greenhouse indoor climate by means of an asynchronous motor for ventilation, heating, humidification, etc. An intelligent system to control these actuators for an optimal inside climate was implemented in the model. The dynamic model was validated by comparing the simulation results to experimental measurements. These results showed the effectiveness of the control strategy in regulating the greenhouse indoor climate. Finally, a photovoltaic generator was modeled, with the aim of reducing the costs of agricultural production. It feeds the asynchronous motor with a vector control optimized by fuzzy logic that drives a variable speed fan.

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Simulation and control of ventilation rates in greenhouses

Cited by 30 publications

References 28 publications

Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods

Intelligent Control of the Microclimate of an Agricultural Greenhouse Powered by a Supporting PV System

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