Thermal Performance of an Unheated Greenhouse Under Semi-Arid Conditions During the Night

Mesmoudi, Kamel; Bougoul, S.; Bournet, P.E.

doi:10.17660/actahortic.2012.952.52

Cited by 9 publications

(11 citation statements)

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“…The average internal temperatures for each case were 9.48, 7.41 and 6.59 °C for the 19:00, 00:00 and 05:00 hours, respectively. The ∆T generated under this condition for the considered hours were -3.61, -2.7 and -2.62 ºC respectively, which indicates that under these atmospheric conditions and without any type of heating system, the thermal inversion occurs, as has already been demonstrated in previous studies (Mesmoudi et al, 2012;Montero et al, 2013). This phenomenon is generated mainly by an accelerated loss of heat through the roof and the flow of heat extracted from the interior of the greenhouse through the fixed overhead openings (Teitel et al, 2008).…”

Section: Thermal Behavior Scenario a -Dry Clear Sky Nightsupporting

confidence: 80%

Study using a CFD approach of the efficiency of a roof ventilation closure system in a multi-tunnel greenhouse for nighttime microclimate optimization

Villagrán

Bojacá

2020

Rev. Ceres

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Section: Thermal Behavior Scenario a -Dry Clear Sky Nightsupporting

confidence: 80%

Study using a CFD approach of the efficiency of a roof ventilation closure system in a multi-tunnel greenhouse for nighttime microclimate optimization

Villagrán

Bojacá

2020

Rev. Ceres

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“…The values of the highest normalized velocity agreed with the time when the temperature of the outside environment started to decrease, therefore it can be mentioned that this acceleration of the air flow inside the greenhouse may be strongly associated with the thermal effect of natural ventilation by buoyancy; an effect that generally produces rapid changes in temperature and velocity inside a greenhouse [59]. This buoyancy phenomenon is caused by convective movements generated between the soil and the greenhouse cover, since at that time the soil is the surface of higher temperature due to energy storage throughout the day, while the cover usually cools rapidly to the level of the outside ambient temperature [34,60].…”

Section: Air Velocity Inside the Greenhouse And Calculated Ventilation Ratesmentioning

confidence: 99%

Contribution to the Sustainability of Agricultural Production in Greenhouses Built on Slope Soils: A Numerical Study of the Microclimatic Behavior of a Typical Colombian Structure

2021

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The use of covered structures is an alternative increasingly used by farmers to increase crop yields per unit area compared to open field production. In Latin American countries such as Colombia, productive areas are located in with predominantly hillside soil conditions. In the last two decades, farmers have introduced cover structures adapted to these soil conditions, structures for which the behavior of factors that directly affect plant growth and development, such as microclimate, are still unknown. Therefore, in this research work, a CFD-3D model successfully validated with experimental data of temperature and air velocity was implemented. The numerical model was used to determine the behavior of air flow patterns and temperature distribution inside a Colombian passive greenhouse during daytime hours. The results showed that the slope of the terrain affects the behavior of the air flow patterns, generating thermal gradients inside the greenhouse with values between 1.26 and 16.93 °C for the hours evaluated. It was also found that the highest indoor temperature values at the same time were located in the highest region of the terrain. Based on the results of this study, future researches on how to optimize the microclimatic conditions of this type of sustainable productive system can be carried out.

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“…Nevertheless, few investigations of the performance of greenhouses in southern Mediterranean climates have been undertaken so far, and the involved physical mechanisms remain poorly understood. Some progress was made in recent years since the energy balance and the behavior of the indoor microclimate has long become a matter of concern in the studies conducted by a number of researchers …”

Section: Introductionmentioning

confidence: 99%

“…Some progress was made in recent years since the energy balance and the behavior of the indoor microclimate has long become a matter of concern in the studies conducted by a number of researchers. [20][21][22][23] Performance criteria based on very different approaches are difficult to compare, and a common approach based clearly on the same bioclimatic stage is required so that greenhouse performance can be simulated and examined with respect to their engineering design (both greenhouse geometry and covering material). Under arid climate conditions, few CFD works that predict and analyze the microclimate of greenhouses exist.…”

Section: Introductionmentioning

confidence: 99%

Effect of the greenhouse design on the thermal behavior and microclimate distribution in greenhouses installed under semi‐arid climate

Mesmoudi

Meguallati

Bournet

2017

Heat Trans. Asian Res.

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Greenhouse design and cover material properties may strongly impact greenhouse energy. To study the effect of these parameters, three typical unheated agricultural buildings equipped with rows of canopy were considered, and two‐dimensional simulations were conducted using the discrete ordinate model for simulating radiative transfers. Experiments were conducted to establish the boundary conditions and to validate the model. Two parametric studies were carried out: one for the nocturnal period when the energy performance of each type of greenhouse was investigated, and one for the diurnal period, when the sun path was simulated taking into account the type of the cover, its spectral optical and thermal properties. Results indicate that for the diurnal period, and for both plastic greenhouses equipped with fully opened side vents, the air located between the rows of canopy and ground surfaces remained very slow, not exceeding 0.2 m/s; for the Venlo glasshouse, the recirculation loop situated above the crop improved the air mixing and induced a good homogenization. Results also indicate that the cover material with the highest absorptivity, deteriorated the natural ventilation, increasing the air temperature by convection, enhancing local air temperature favoring the development of a secondary recirculation, and reduced the available photosynthetically active radiation. Concerning the nocturnal period, the ambient air temperature in the tunnel and in the vertical wall of the greenhouse was relatively homogenous and warmer than the temperature in the Venlo greenhouse. During the nocturnal period, the plastic greenhouse (in particular the one with the tunnel) performed better in regard to the homogenization of the climate and thermal energy storage.

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Thermal Performance of an Unheated Greenhouse Under Semi-Arid Conditions During the Night

Cited by 9 publications

References 0 publications

Study using a CFD approach of the efficiency of a roof ventilation closure system in a multi-tunnel greenhouse for nighttime microclimate optimization

Study using a CFD approach of the efficiency of a roof ventilation closure system in a multi-tunnel greenhouse for nighttime microclimate optimization

Contribution to the Sustainability of Agricultural Production in Greenhouses Built on Slope Soils: A Numerical Study of the Microclimatic Behavior of a Typical Colombian Structure

Effect of the greenhouse design on the thermal behavior and microclimate distribution in greenhouses installed under semi‐arid climate

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