J.of Soc of Agri Struc, Japan.
Vol.23,No.2 November 1992,67-71
Original:
Language: Japanese

A Study on Natural Ventilation of Greenhouse in Taiwan(1)
-The Air Permeability of Insect Screen Used in Ventilation Opening of Greenhouse-

Yu-I HUANG, Yoshiyasu AIHARA, Tomoyuki SENO and Makoto NARA

Summary

    Ventilation opening covered with screen are being utilized for eliminating insect infestationsin the greenhouses in Taiwan. In this study, air permeability of seven types of insect screens was investigated. The result showed that air exchangeindex(n) was in the region of 1.70-1.88, and the air exchange rate (a.m3/(m2.min.Pa1/n)) increased with larger porosities of screen by a function of a =1.36 x 102.35μ. When Reynolds number were about 400, pressure loss coefficient (*) obtained for each screen became constant, and the relation between * and μ was deduced to *= 0.95(1-μ)/μ2.

Keywords: greenhouse, insect screen, air permeability

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