Effect of vent configuration and insect screen on greenhouse microclimate

In this paper the effect of insect screens and vent configuration of a tunnel greenhouse cultivated with a tomato crop on airflow, temperature and humidity patterns was numerically analyzed using a commercial computational fluid dynamics (CFD) code. The numerical model was firstly validated against experimental data, which were carried out in an arch plastic covered greenhouse with continuous side openings. The three components of air velocity and the spatial distribution of air temperature and humidity were measured using a sonic anemometer and fast response sensors respectively. After the good agreement between experimental and numerically obtained results the code was used for parametric studies concerning the effect of different insect screens and vent configuration on the inside climate. Data from the experiments were used to define proper and realistic boundary conditions in the numerical model. A gradual increase of air temperature and humidity and a decrease of air velocity were observed as the porosity of the tested insect screen was reduced. It was found that vent configuration affects the ventilation rate and the climate distribution inside the greenhouse.