Yuko Ogura

On the Transmission Coefficient of the Air-conditioned Glasshouse

The over-all transmission coefficient of air-conditioned glasshouse (Rall) is given by the following formula.Rall=Rf⋅Rg⋅RdThis report is a discussion on these factors; the ratio of decrease by frame work (Rf), the transmission coefficient of glass (Rg) and the ratio of reduction in transmission by dust and sedimentation (Rd) .The ratio of decrease by frame is estimated to be about 0.85 on an average by the measurement of the frame ratio (11-18.2%) of various glasshouses. The transmission coefficient of glass for total radiation is estimated to be about 0.89. The ratio of reduction in transmission by dust and sedimentation was measured about 0.80 in one year, but it is generally most difficult to determine of these three factors because remarkable variations occur according to circumstances.The over-all transmission coefficient of a whole day, 0.49-0.57, on the average at all seasons is a little smaller than the mean value at midday in summer, 0.586. The author discussed on the influences of the radiation energy and condensed water drop on the over-all transmissoion coefficient.