Improvement of Air Flow Circulation and Daytime CO2 Concentration Using Wind Direction Plates in the Intelligent Greenhouse

• Published in: Shokubutsu Kankyo Kogaku Vol. 33; no. 2; pp. 69 - 76
• Main Authors: OBATA, Keigo, UEKA, Yuko, ARIMA, Seiichi
• Format: Journal Article
• Language: English; Japanese
• Published: Fukuoka Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists 2021; Japan Science and Technology Agency
• Subjects: Air circulation; Air flow; Carbon dioxide; Circulation; computational fluid dynamics; Computer applications; Cultivation; gas environment; greenhouse; Greenhouses; Photosynthesis; Plant communities; Plates; Skylights; Velocity; Wind; Wind direction; Wind speed
• ISSN: 1880-2028; 1880-3563
• DOI: 10.2525/shita.33.69

Within a greenhouse, air circulation is maintained through circulation fans and ventilation windows. It is believed that a wind velocity of approximately 0.5 m s-1 is required to promote photosynthesis. Conventional skylight construction provides very low wind velocity in cultivation areas and inadequate airflow circulation. Besides, the CO2 concentration in a greenhouse during the day is lower than that in outside air.In this study, wind direction plates, constructed with vinyl, were installed on the ridge of a greenhouse, and the effect was verified using actual measurement and computational fluid experiments. Vertical inflow of outside air was measured and numerical fluid analysis was also employed, and the outside air was confirmed to have reached the cultivation area. In particular, the effect of the vertical airflow was observed just below the upwind opening of the skylight, and the wind speed near the plant community reached 0.5 m s-1.In addition, it was confirmed that the decrease in CO2 concentration in the cultivation area was suppressed, and subsequent recovery proceeded uniformly and promptly.