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Abstract: The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms⁻¹, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.

[1] Andre, N., Albright, L.D., 1994. Criterion for establishing similar air flow patterns (isothermals) in slotted-inlet ventilated enclosures. Trans. ASAE, 37:235-250.

[2] Bartzanas, T., Boulard, T., Kittas, C., 2004. Effect of vent arrangement on windward ventilation of a tunnel greenhouse. Biosystems Engineering, 88(4):479-490.

[3] Boulard, T., Draoui, B., 1995. Natural ventilation of a greenhouse with continuous roof vents: Measurements and data analysis. Journal of Agricultural Engineering Research, 61:27-36.

[4] Boulard, T., Meneses, J.F., Mermier, M., Papadakis, G., 1996. The mechanisms involved in the natural ventilation of greenhouse. Agricultural and Forest Meteorology, 79:61-77.

[5] Fernández, J.E., Bailey, B.J., 1992. Measurements and prediction of greenhouse ventilation rates. Agricultural and Forest Meteorology, 58:229-245.

[6] Kittas, C., Draoui, B., Boulard, T., 1995. Quantification of the ventilation of a greenhouse with roof opening. Agricultural and Forest Meteorology, 77:95-111.

[7] Kittas, C., Boulard, T., Papadakis, G., 1997. Natural ventilation of a greenhouse with ridge and side openings: Sensitivity to temperature and wind effects. Trans. ASAE, 40(2):415-425.

[8] Linden, P.F., Lane-Serf, G.F., Smeed, D.A., 1990. Emptying filling Boxes: The fluid mechanics of natural ventilation. Journal of Fluid Mechanics, 212:309-335.

[9] Papadakis, G., Mermier, M., Meneses, J.F., Boulard, T., 1996. Measurements and analysis of air exchange rates in a greenhouse with continuous roof and side openings. Journal of Agricultural Engineering Research, 63:219-228.

[10] Pearson, C.C., Owen, J.E., 1994. The resistance to air flow of farm building ventilation components. Journal of Agricultural Engineering Research, 57:53-65.

[11] Pérez Parra, J., Baeza, E., Montero, J.I., Bailey, B.J., 2004. Natural ventilation of parral greenhouse. Biosystems Engineering, 87(3):355-366.

[12] Teitel, M., Tanny, J., 1999. Natural ventilation of greenhouse: Experiments and model. Agricultural and Forest Meteorology, 96:59-70.

[13] Whittle, R.M., Lawrence, W.J.C., 1960. The climatology of glasshouses. II. ventilation. Journal of Agricultural Engineering Research, 5:36-41.