Articles
The influence of near-infrared radiation cut film on the thermal environment in a greenhouse during the summer season
Article number
1423_14
Pages
105 – 112
Language
English
Abstract
In greenhouse cultivation, high-temperature suppression during the summer is an important issue.
Near-infrared radiation (NIR)-cut films have been attracting attention as a covering material reducing high temperatures in greenhouses.
The aim of this study was to investigate the effect of a NIR-cut film on the thermal environment in a greenhouse during summer season.
A polyolefin (PO) film (PO_Normal) and a NIR-cut PO film (PO_NIRCut) were installed on two greenhouses (floor area: ~60 m2, height: ~3.0 m, orientation: north-south), in Tsukuba, Ibaraki, Japan.
Air and soil temperature and solar radiation were measured in each greenhouse from August 24-26, 2023, without plants.
The side windows of the greenhouse were kept open at all times during the measurements.
The integrated solar radiation under PO_NIRCut was lower than under PO_Normal because a portion of NIR and photosynthetically active radiation (PAR) in the solar radiation was blocked by PO_NIRCut.
No apparent differences were observed in air temperatures between greenhouses because the greenhouses used in this research were small and the ventilation frequency were relatively high.
Average soil temperatures under PO_NIRCut were lower than those under PO_Normal by 3.1°C (6:00-18:00), 1.7°C (18:00-6:00), and 2.4°C (all day). PO_NIRCut reduced NIR and PAR energy incidence on the ground surface in the greenhouse, resulting in lower soil temperatures.
The results suggest that the use of NIR-cut film suppressed the increase in soil temperature inside the greenhouse.
The fact that soil temperature under PO_NIRCut was lower than that under PO_Normal at nighttime (18:00-6:00) means that the amount of heat stored in the soil from daytime solar radiation was lower under PO_NIRCut.
This study could increase insights into NIR cut film’s impact on the summer greenhouse’s thermal environment.
Near-infrared radiation (NIR)-cut films have been attracting attention as a covering material reducing high temperatures in greenhouses.
The aim of this study was to investigate the effect of a NIR-cut film on the thermal environment in a greenhouse during summer season.
A polyolefin (PO) film (PO_Normal) and a NIR-cut PO film (PO_NIRCut) were installed on two greenhouses (floor area: ~60 m2, height: ~3.0 m, orientation: north-south), in Tsukuba, Ibaraki, Japan.
Air and soil temperature and solar radiation were measured in each greenhouse from August 24-26, 2023, without plants.
The side windows of the greenhouse were kept open at all times during the measurements.
The integrated solar radiation under PO_NIRCut was lower than under PO_Normal because a portion of NIR and photosynthetically active radiation (PAR) in the solar radiation was blocked by PO_NIRCut.
No apparent differences were observed in air temperatures between greenhouses because the greenhouses used in this research were small and the ventilation frequency were relatively high.
Average soil temperatures under PO_NIRCut were lower than those under PO_Normal by 3.1°C (6:00-18:00), 1.7°C (18:00-6:00), and 2.4°C (all day). PO_NIRCut reduced NIR and PAR energy incidence on the ground surface in the greenhouse, resulting in lower soil temperatures.
The results suggest that the use of NIR-cut film suppressed the increase in soil temperature inside the greenhouse.
The fact that soil temperature under PO_NIRCut was lower than that under PO_Normal at nighttime (18:00-6:00) means that the amount of heat stored in the soil from daytime solar radiation was lower under PO_NIRCut.
This study could increase insights into NIR cut film’s impact on the summer greenhouse’s thermal environment.
Authors
Y. Ohashi, R. Tsuchiya, M. Ishii, M. Hayashi
Keywords
covering material, high-temperature suppression, polyolefin film, soil temperature, solar radiation
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