Evaluation Indicator for Greenhouse Air Circulator Performances

Kuroyanagi, Takeshi

doi:10.1016/s1881-8366(13)80009-2

Cited by 6 publications

(4 citation statements)

References 8 publications

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“…The first is the uneven distribution of CO 2 in the cultivation area. Using circulation fans to provide air movement seems to be an ideal method for solving this problem 45 . However, in this study, the cultivators did not use circulation fans in the greenhouses, possibly due to anticipated pest control difficulties.…”

Section: Eco-friendly Strategy For Co 2 Enrichment In Commercial Gree...mentioning

confidence: 99%

Eco-friendly strategy for CO2 enrichment performance in commercial greenhouses based on the CO2 spatial distribution and photosynthesis

Zhang,

Yasutake,

Hidaka

et al. 2023

Sci Rep

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CO2 enrichment is an essential environmental control technology due to its significantly enhancing effect on crop production capacity. Despite being a key energy consumer in protected agriculture (i.e. greenhouse systems), CO2 enrichment remains at a low energy use efficiency level, highlighting the need for developing more energy-efficiency strategies for CO2 enrichment. Therefore, this study employed the computational fluid dynamics (CFD) simulation method to replicate the CO2 diffusion process resulting from CO2 enrichment in three commercial strawberry greenhouses with varying geometric characteristics. Based on the CFD-simulated CO2 concentration distributions, the leaf photosynthetic rate was calculated using a mathematical model group. The CO2 enrichment efficiency was then analysed by calculating the ratio of increased photosynthesis across the cultivation area to the amount of energy (in CO2 equivalent) used. The efficiency peaked when the average CO2 concentration was approximately 500 μmol mol−1, thereby providing guidance for determining the target concentration of CO2 enrichment in production. Although this study is limited as the CFD simulation only considered a typical short-period CO2 enrichment event, future research will provide a broader analysis by considering changes throughout the day.

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Section: Eco-friendly Strategy For Co 2 Enrichment In Commercial Gree...mentioning

confidence: 99%

Eco-friendly strategy for CO2 enrichment performance in commercial greenhouses based on the CO2 spatial distribution and photosynthesis

Zhang,

Yasutake,

Hidaka

et al. 2023

Sci Rep

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“…The air circulation coverage of six commercial fans was previously investigated using an identical protocol (Kuroyanagi 2013a). Airflow created by each fan was measured in a closed and empty garage (8.5 m in width, 33.6 m in depth, and 6.1 m in height).…”

Section: Performance Indicatormentioning

confidence: 99%

“…The authors did not discuss the reason why horizontal airflow reduced the vertical gradient of air temperature and relative humidity. It could be explained by a circulation of airflow along the gable end wall of the high tunnel because airflow from a commercial air circulator reaches 20 m and more ahead (Kuroyanagi 2013a). Matsuura et al (2004) also reported that air circulation significantly increased the yield in January from 369 g m -2 for the control tunnel to 622 g m -2 for the tunnel with the fan (P = 0.0047).…”

Section: Uniform Air Temperature and Humiditymentioning

confidence: 99%

Current Usage of Air Circulators in Greenhouses in Japan

Kuroyanagi

2016

JARQ

Self Cite

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In the last decade, air circulators have been widely used in greenhouses and high tunnels in Japan. The main purpose of air circulation is to provide uniformity in temperature, humidity level, and carbon dioxide concentration in greenhouse air. In addition, empirical knowledge that air circulation prevents hygrophilous diseases increased among growers, together with the inference that air circulation reduces the fuel consumption required for heating. Although the benefits of air circulation remain uncertain, some empirical evidence has been obtained from horticultural and engineering studies in Japan. In this review, the results of these investigations are summarized on the basis of five aspects: performance indicators for circulators, microclimate uniformity, crop yield, suppression of hygrophilous diseases and possible mechanisms. Practical issues regarding the installation of air circulators for greenhouses and high tunnels are also discussed.

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“…In a study on the influence of air disturbance on the variation of canopy temperature in a double-span greenhouse, Ishii et al (2012) found that the SD of canopy temperature under air disturbance with air velocity of 0.5 m/s was less than 0.6°C, and the SD of canopy temperature without air disturbance was more than 1.1°C. Stagnant air will form a boundary layer on the surface of plants, and as a result, the physiological processes of crops are suppressed (Kuroyanagi, 2013;Kuroyanagi et al, 2013;Takayama et al, 2014). Appropriate air disturbance can regulate the microenvironment of plant canopy leaves, promote energy exchange between the crop canopy and the surrounding environment, reduce CO 2 exchange resistance, increase CO 2 concentration in the microenvironment of leaves, and improve the transpiration rate and promote photosynthesis (Elings et al, 2007).…”

mentioning

confidence: 99%

Design of an Air Blowing Device Above Seedbed: The Effect of Air Disturbance on the Microenvironment and Growth of Tomato Seedlings

Li¹,

Li²,

Wu³

et al. 2020

horts

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In recent years, air circulation has been used in protected cultivation to improve the microenvironment around seedlings, which in turn enhances photosynthesis and seedling growth. However, a practical and precise air circulation device has not yet been reported, especially one for growing seedlings in a greenhouse. Considering the use of a seedbed in seedling cultivation, a blower that can move back and forth on the seedbed and accurately control the air velocity is designed. In this experiment, we take the nonblowing treatment as the control (CK); three air velocities (0.3, 0.6, and 0.9 m/s) were selected to investigate the effect of interval blowing on the microenvironment of the canopy, physiology of seedling growth, stomatal characteristics of leaves, and stem mechanics of tomato seedlings. The three air velocities were found to significantly reduce the canopy temperature by 0.44, 0.78, and 1.48 °C lower than the CK, respectively, and leaf temperature by 0.83, 1.57, and 2.27 °C lower than the CK, respectively, in cultivated seedlings during summer. The relative humidity of the tomato seedling canopy decreased by 2.7% to 7.0%. Compared with the CK, the plant height of tomato seedlings decreased by 13.54% and root dry mass, root-shoot ratio, and seedling quality index (SQI) increased by 34.63%, 21.43%, and 14.29%, respectively, at 0.6 m/s. In addition, mechanical indexes such as hardness and elasticity of the tomato seedling stem were higher under air disturbance than those of the CK. The best effect was seen in the treatment with the air velocity of 0.6 m/s, in which the hardness and elasticity of the stem base and the first node were significantly higher than that of the CK. In conclusion, air disturbance generated by the air blowing device we designed effectively improved the microenvironment around the plants, enhanced the physiological activity of the seedlings, and thereby promoted seedling growth.

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Evaluation Indicator for Greenhouse Air Circulator Performances

Cited by 6 publications

References 8 publications

Eco-friendly strategy for CO2 enrichment performance in commercial greenhouses based on the CO2 spatial distribution and photosynthesis

Eco-friendly strategy for CO2 enrichment performance in commercial greenhouses based on the CO2 spatial distribution and photosynthesis

Current Usage of Air Circulators in Greenhouses in Japan

Design of an Air Blowing Device Above Seedbed: The Effect of Air Disturbance on the Microenvironment and Growth of Tomato Seedlings

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