Özet:

During periods when the intensity of solar radiation is high, it is possible to provide the comfortable environment desired by plants in greenhouses with natural ventilation as the cheapest method. In the greenhouse where plant production is carried out, with good ventilation, the air temperature is become above the external temperature by 1-2 °C, while the plant temperature can rise above the air temperature by 5-15 °C. For this reason, ventilation and shading together are considered an effective method of air conditioning in providing a plant comfortable environment during hot periods. The ventilation rate of air is an important parameter used to determine the ventilation efficiency in greenhouses. The number of air changes (ventilation rate) varies depending on the size, location of the ventilation openings, and the porosity of the insect tulle used in the ventilation openings. In this study, depending on the size of the ventilation openings and the porosity coefficient of the insect tulle used, and the wind speed, the ventilation rate, and the temperature difference that could be reached were determined. As a result of the calculations, in 50% shaded greenhouse and when the ventilation openings area on the roof to the greenhouses floor area was 40% while the insect tulles were used on the ventilation openings, the temperature difference was determined as 1.6 °C according to the air change coefficient of 30 h-1 that was achieved in the greenhouses.

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