Greenhouse daily sun-radiation intensity variation, daily temperature variation and heat profits through the polymeric cover

Leonidopoulos, Georgios

doi:10.1016/s0142-9418(99)00051-3

Cited by 2 publications

(2 citation statements)

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“…The solar position and outside weather conditions also contribute to the τ gh . A variety of studies on the τ gh have considered the incidence angle of solar radiation (Bowman, 1970), weather conditions (Leonidopoulos, 2000;Cabrera et al, 2009), greenhouse orientation (Papadakis et al, 1998;Li et al, 2000), structural members (Critten, 1987), and dust and dirt on the covering (Geoola et al, 1998). Because the results on τ gh vary from 25% to 59%, according to experimental conditions, applying a specific τ gh for the energy input equation was difficult.…”

Section: Al 2009mentioning

confidence: 99%

Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization

Yang

Son

Lee

et al. 2016

Span. j. agric. res.

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This study concentrates on the utilization of surplus thermal energy (STE) in greenhouses. Even in the cold season, the thermal energy input from solar radiation easily exceeds the required amount for heating on a clear day in the temperate or subtropical regions. This excessive solar energy is regarded as STE. There are several studies related to the STE energy (Pavlou, 1991; Suh et RESEARCH ARTICLE OPEN ACCESS AbstractIf a greenhouse in the temperate and subtropical regions is maintained in a closed condition, the indoor temperature commonly exceeds that required for optimal plant growth, even in the cold season. This study considered this excess energy as surplus thermal energy (STE), which can be recovered, stored and used when heating is necessary. To use the STE economically and effectively, the amount of STE must be estimated before designing a utilization system. Therefore, this study proposed an STE model using energy balance equations for the three steps of the STE generation process. The coefficients in the model were determined by the results of previous research and experiments using the test greenhouse. The proposed STE model produced monthly errors of 17.9%, 10.4% and 7.4% for December, January and February, respectively. Furthermore, the effects of the coefficients on the model accuracy were revealed by the estimation error assessment and linear regression analysis through fixing dynamic coefficients. A sensitivity analysis of the model coefficients indicated that the coefficients have to be determined carefully. This study also provides effective ways to increase the amount of STE.Additional key words: energy balance; energy conservation; environmental control; heat pump; heat storage Abbreviations used: FCU (fan coil unit); HST (high temperature heat storage tank); LST (low temperature heat storage tank); mPLAI (modified PLAI, ratio of total projected leaf area to the floor area); PLAI (projected leaf area index, projected area of horizontal leaves per unit of horizontal land below); SHEF (sensible heat emission factor); STE (surplus thermal energy) Citation: Yang, S. H.; Son, J. E.; Lee, S. D.; Cho, S. I.; Ashtiani-Araghi, A.; Rhee, J. Y. (2016). Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization.

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Section: Al 2009mentioning

confidence: 99%

Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization

Yang

Son

Lee

et al. 2016

Span. j. agric. res.

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“…The growth conditions used in almost all experiments indoors are temporarily and spatially less variable than those in natural environments (Frenkel, Jankanpaa, Moen, & Jansson, 2008). The temperatures are usually constant or at the best varying between diurnal values, while the light intensity is generally lower and with a spectral composition differing quite significantly from that of the sun (Leonidopoulos, 2000;Young, McMahon, Rajapakse, & Decoteau, 1994). On the other hand, while in common garden experiments, phenology can be studied in natural light and temperature conditions, the local versus foreign effect cannot be tested rigorously (Allendorf & Lundquist, 2003).…”

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Effect of climate change on bud phenology of young aspen plants (Populus tremula. L)

Sivadasan

Randriamanana

Chenhao

et al. 2017

Ecology and Evolution

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Boreal tree species are excellent tools for studying tolerance to climate change. Bud phenology is a trait, which is highly sensitive to environmental fluctuations and thus useful for climate change investigations. However, experimental studies of bud phenology under simulated climate change outdoors are deficient. We conducted a multifactorial field experiment with single (T, UVA, UVB) and combined treatments (UVA+T, UVB+T) of elevated temperature (T, +2°C) and ultraviolet‐B radiation (+30% UVB) in order to examine their impact on both male and female genotypes of aspen (Populus tremula L.). This study focuses on the effect of the treatments in years 2 and 3 after planting (2013, 2014) and follows how bud phenology is adapting in year 4 (2015), when the treatments were discontinued. Moreover, the effect of bud removal was recorded. We found that elevated temperature played a key role in delaying bud set and forcing bud break in intact individuals, as well as slightly delaying bud break in bud‐removed individuals. UVB delayed the bud break in bud‐removed males. In addition, both UVA and UVB interacted with temperature in year 3 and even in year 4, when the treatments were off, but only in male individuals. Axillary bud removal forced both bud break and bud set under combined treatments (UVA+T, UVB+T) and delayed both under individual treatments (T, UVB). In conclusion, male aspens were more responsive to the treatments than females and that effect of elevated temperature and UV radiation on bud set and bud break of aspen is not disappearing over 4‐year study period.

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Greenhouse daily sun-radiation intensity variation, daily temperature variation and heat profits through the polymeric cover

Cited by 2 publications

References 1 publication

Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization

Surplus thermal energy model of greenhouses and coefficient analysis for effective utilization

Effect of climate change on bud phenology of young aspen plants (Populus tremula. L)

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