HortScience (Jan 2025)

Greenhouse Covering Material Overall Heat-transfer Coefficient Determination Using Contour Plots

  • Yuta Ohashi,
  • Ryota Tsuchiya,
  • Masahisa Ishii,
  • Makio Hayashi

DOI
https://doi.org/10.21273/HORTSCI18217-24
Journal volume & issue
Vol. 60, no. 2

Abstract

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Improving greenhouse heat-insulating performance requires covering materials with low overall heat-transfer coefficients. We constructed a contour plot using equations relating this coefficient to longwave radiation absorptance under different outdoor downward longwave radiation levels. It revealed that the coefficient ranged from 4.7 to 7.7 W·m−2·K−1, decreasing with increasing downward longwave radiation and longwave radiation absorptance. This method facilitates rapid estimation of overall heat-transfer coefficients under different downward longwave-radiation levels, based on longwave-radiation absorptance.

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